- Email: [email protected]
Disorders of the Hair in Children
Symposium on Pediatric Dermatology
Disorders of the Hair in Children Vera H. Price, M.D., FR.C'p. (C)*
The assessment of an infant or child with hair loss involves taking a detailed history and performing a careful clinical examination, and microscopic hair examination in many instances. In taking the history, it is important to determine first whether the hair is coming out with the roots attached, as in alopecia areata, or whether the hair is breaking off at some point distal to the roots, as in trichotillomania or tinea capitis. Other important aspects of the history include the duration of the hair disorder, drug intake, mental state, physical development (including state of teeth, nails, eyes, and presence of heat intolerance), past medical history, hair style and hair care and cosmetics, and family history of hair problems. In the clinical examination, the hair texture, length, style, and pattern and distribution of hair loss are noted. A "pull test" is useful in determining whether the hair is shedding excessively, as in alopecia areata (around the margins of active lesions) or in some of the congenital alopecias. The test is done by grasping 8 to 10 closely grouped hairs near and scalp with the thumb, index, and middle fingers, and applying traction as the fingers are pulled firmly and slowly away from the scalp. Normally, 0 to 2 hairs are pulled out by this method. If excessive shedding is present 4 to 6 or more hairs are easily and painlessly pulled out. Another useful test is to examine the hair tips against a contrasting background to see if they are tapered or broken. The scalp itself is assessed for the presence of scaling, inflammation, cradle cap, infection, and scarring. Hair elsewhere on the body is examined to determine if there is too much or too little in other sites. Teeth, nails, and the mental state are evaluated, and the presence of absence of sweating is noted. Light microscopic examination of a hair mount frequently provides helpful information. When a fungus infection is suspected, a few short, broken hairs are mounted in potassium hydroxide, which dissolves the keratin and allows easy visualization of fungal elements. When a hair-shaft anomaly is suspected and one wishes to examine the ':'Associate Clinical Professor, Department of Dermatology, University of California, San Francisco; Department of Dermatology, Kaiser-Permanente Medical Center, San Francisco, California
Pediatric Clinics of North America- Vol. 25, No.2, May 1978
305
306
VERA
H.
PRICE
hair shaft itself, balsam, Permount, or synthetic resin are used because in these media, the hair is seen sharply and without surface light scatter. In order to understand normal hair growth as well as the response of hair to various insults, it is important to understand the human hair growth cycle. Every hair follicle has a regular period of activity and another of rest. During the growth phase, called the anagen phase, the cells in the hair matrix are actively dividing and producing a growing hair. The anagen phase in the human scalp lasts 2 to 6 years, or approximately 1000 days. The anagen phase is followed by the resting period, called the telogen phase, during which mitotic activity in the hair matrix ceases and the hair stops growing. The telogen phase lasts about 3 months, or approximately 100 days. The old resting hair is eventually pushed out of the follicle by the new growing hair coming up from below, and is shed. There are approximately 100,000 hairs on the average human scalp. About 90 per cent of these hairs are in the anagen phase, and about 10 per cent are in the telogen phase. As follicular activity is not synchronized in adjacent follicles, the 100 hairs that represent the average daily hair loss come from follicles allover the scalp, and this daily shedding is not particularly noticed by most individuals. Human hair grows approximately 1 cm in 1 month, which represents a production of about 30 meters of hair per day! Present knowledge allows the classification of disorders of the hair in children detailed below: I. Physiologic hair loss Shedding of the newborn Temporal recession at puberty II. Congenital alopecias, hypotrichosis, hypertrichosis III. Structural hair shaft anomalies A. With increased hair fragility 1. Monilethrix 2. Bamboo hair (trichorrhexis invaginata) 3. Trichorrhexis nodosa a. congenital i. trichorrhexis congenita ii. with argininosuccinicaciduria b. acquired i. proximal trichorrhexis nodosa ii. distal trichorrhexis nodosa 4. Pili torti a. classic pili torti b. with copper deficiency; trichopoliodystrophy B. Without increased hair fragility 1. Pili annulati 2. Pseudo pili annulati 3. Woolly hair IV. Alopecia areata V. Trichotillomania VI. Traction and traumatic alopecia VII. Infections VIII. Toxic alopecia IX. Nutritional, metabolic hair loss X. Hormonal influence on hair growth
DISORDERS OF THE HAIR IN CHILDREN
307
PHYSIOLOGIC HAIR LOSS Shedding of the Newborn Lanugo hair is the first silky hair made by hair follicles in utero, and is -present over the entire fetus. It is normally shed in utero and replaced by vellus hair in all regions except the scalp, eyebrows, and eyelashes, where the lanugo is replaced by terminal hair. The second growth begins prenatally in the sixth to eighth months and continues postnatally.I5 The "secondary hair" has a short growing phase and is shed within the first year of life. This physiologic shedding is temporary and is no cause for concern. The shed hair is replaced by thicker, longer, and darker hair. Temporal Recession at Puberty The frontal hairline in children is straight. In late puberty, increased androgen levels cause the transition from terminal to vellus hair at the frontal hairline, changing the hairline to an "M" shape. This change occurs in both sexes. It does not occur in eunuchs.
CONGE NIT AL ALOPECIAS, HYPOTRICHOSIS, HYPERTRICHOSIS A variety of congenital and hereditary disorders is associated with abnormalities of the hair. The hair may be totally absent (alopecia), unusually sparse (hypotrichosis), or overabundant in its growth (hypertrichosis).37 In rare instances, congenital alopecia occurs as an isolated defect, inherited as an autosomal recessive trait. In most instances, however, the hair abnormality - which may include changes in density, color, caliber, and fragility - is only part of a complex congenital or hereditary disorder. There is as yet no satisfactory way to classify this diverse group of conditions. Some are associated with other ectodermal defects (i.e., hidrotic and anhidrotic ectodermal dysplasia), some with skeletal defects (Le., cartilage-hair hypoplasia, oral-facialdigital syndrome), some with amino acid disorders (i.e., phenylketonuria, homocystinuria), and some with chromosomal defects (Le., Cornelia de Lange syndrome, Down's syndrome).27
STRUCTURAL HAIR-SHAFT ANOMALIES The structural hair-shaft anomalies are an important group of disorders which may, in some instances, provide a clue to widespread pathology such as an inborn error of metabolism. Because each anomaly has a highly distinctive morphology, the diagnosis is easily made in the office with a microscopic hair-mount examination. Hair-shaft disorders may be divided into two groups: those that cause increased hair fragility and breakage, and those that do not cause increased hair fragility and breakage.
308
VERA
H.
PRICE
Figure 1. Monilethrix in a hair mount. (From Price, V. H.: Office diagnosis of structural hair anomalies. Cutis, 15:231, 1975, with permission.)
Hair-Shaft Anomalies with Increased Hair Fragility MONILETHRIX. Monilethrix is a distinctive, rare hair defect inherited as a simple dominant trait22 , 39 and named after the resemblance of the affected hair shaft to a string of beads. In infancy, the hair breaks, leaving the scalp covered with broken hair 0.5 to 2.5 cm long. The scalp is the main site affected, but hair in other areas may also be affected in various degrees. A hair mount shows the distinctive "nodes," which have the diameter of normal hair and are medullated, alternating rhythmically with the "internodes," which are constricted, nonmedullated, and are the sites of fracture (Fig. 1). Keratosis pilaris is always associated with monilethrix and usually occurs on the upper back and shoulders. Occasionally, there are also other ectodermal defects, such as brittle nails, decreased visual fields, juvenile cataracts, and dental lesions. The etiology is unknown. Monilethrix is not associated with argininosuccinicaciduria. 7 ,14 There is no known treatment, but the condition may improve at puberty, with pregnancy, or with oral contraceptives. BAMBOO HAIR (TRICHORRHEXIS INVAGINATA). Bamboo hair (trichorrhexis invaginata) is found in a rare, ectodermal genodermatosis known as "Netherton's disease," which combines ichthyosiform skin changes, the hair-shaft anomaly, and frequently but not invariably, the atopic state. The distinctive hair defect resembles the ball-and-cup joints of bamboo (Fig. 2). The ichthyosiform eruption in the majority of patients is consistent with ichthyosis linearis circumflexa, which features migratory, serpiginous, erythematous, scaling lesions that have a characteristic double-edged scale at the advancing borders.1B,23 In a small number of patients, other forms of ichthyosis have included congenital ichthyosiform erythroderma, sex-linked ichthyosis, and ichthyosis vulgaris. Present evidence suggests an autosomal recessive inheritance; about 60 per cent of those affected are females. 23 Etiology is unknown, but the condition represents a severe disturbance of the keratinization process. Shortly after birth, redness and scaling affect the face and other areas of the body. In the following months or years, the characteristic features of the ichthyosiform process appear. The hair defect appears in infancy, and all hair is affected to some degree. Scalp hair is dry and dull, and so fragile (because of the abnormal invaginations along the shaft) that the hair cannot achieve a
DISORDERS OF THE HAIR IN CHILDREN
309
normal length. The bamboo joints are easily seen in a hair mount; the cup portion of the defect is proximal, and the ball portion, distal (Fig. 2). Hair shafts also show twisting of the shaft, changes in caliber of the shaft, and tulip-like forms.38 Many patients have an atopic diathesis such as flexural eczema, asthma, allergic rhinitis, angioneurotic edema, urticaria, or anaphylactoid reactions. Nb constant laboratory abnormalities have been found. Intermittent aminoaciduria was found in a few patients,18 and hypogammaglobulinemia was present in one patient. 41 Potent topical corticosteroid creams help the skin temporarily, as does the Goeckerman routine. The skin may improve somewhat at puberty, but in general the cutaneous changes persist. The scalp hair tends to improve with age. TRICHORRHEXIS N ODOSA. Trichorrhexis nodosa is the most common of all hair-shaft anomalies. The name refers to the appearance of the defect-a "node"-which in the light microscope is seen to be a hair-shaft fracture in which the individual cortical cells splay out, resembling the ends of two brushes pushed into one another (Fig. 3). Trichorrhexis congenita. In trichorrhexis congenita, the hair-shaft fragility is often the only abnormal clinical feature. The condition may be familial. Scalp hair breaks easily and leaves short, broken ends and areas of partial alopecia. Occasionally, tooth and nail changes also are present.
Figure 2. York, 1978.)
Bamboo hair in a hair mount. (To be published by Gustav Fischer Verlag, New
310
VERA
H.
PRICE
Figure 3. Trichorrhexis nodosa in a hair mount. (To be published by Gustav Fischer Verlag, New York, 1978.)
Trichorrhexis nodosa in mentally retarded infants with argininosuccinicaciduria. This rare syndrome is an example of mental retardation associated with an inborn error of metabolism. 21o 40 Since its recognition in 1958,1 about 20 families have been reported. 4 Mental retardation is evident in the first two years of life, and large amounts of argininosuccinic acid are found in the urine, blood, and cerebrospinal fluid. Many, but not all, of these children have dry, brittle, stubbly hair which shows trichorrhexis nodosa. Normally, argininosuccinic acid, an intermediate in the Krebs-Henseleit urea cycle, is split by the enzyme argininosuccinase to form arginine and fumaric acid. This cleavage enzyme is not present in the blood cells of affected infants; argininosuccinic acid therefore accumulates in the blood and cerebrospinal fluid, and is excreted in the urine. Because normal human hair contains 7.5 to 10.5 per cent of arginine by weight,S the disturbed metabolism of arginine in this condition may lead to faulty keratin formation and structural weakness of hair. The hair defect, when present, is an important diagnostic clue to this systemic disease, and a hair mount should be studied in any infant with mental retardation and peculiar hair. The differential diagnosis includes trichopoliodystrophy (Menkes' steely-hair syndrome). Proximal trichorrhexis nodosa. This common condition, seen only in the black population, presents a distinctive clinical picture.2s Patients complain that their hair will not grow longer than a few centimeters above the scalp (Fig. 4). The inability to grow long hair is due to extreme hair fragility, which causes hair breakage over large portions of the scalp. Frequently, other family members also have a similar problem with short hair. The cause appears to be a genetic predisposition combined with trauma from hair straightening, tight caps, or harsh brushing and combing. The hair is so fragile that a firm lengthwise tug separates a hair into shorter segments. A hair mount of these short, broken segments shows longitudinal splitting, a defective shaft, and trichorrhexis nodosa. The hair breakage usually ceases in
DISORDERS OF THE HAIR IN CHILDREN
311
two to four years if all hair-straightening procedures and vigorous grooming habits are stopped. The use of protein hair conditioners and a wide-toothed, round-tipped comb is recommended. Distal trichorrhexis nodosa. Distal trichorrhexis nodosa is a common condition that occurs in otherwise normal hair as a result of acquired, cumulative cuticular damage. The condition is seen primarily in white and Oriental persons as white specks along the distal 2 to 4 inches of hair.6 The affected hair looks faded and dull and breaks off at various lengths, giving the ends a skimpy appearance. In a hair mount, the white specks show typical fractures of trichorrhexis nodosa (Fig. 3).
Vigorous combing and brushing, prolonged sun exposure, chemical processing, repeated salt-water bathing, and frequent shampooing all contribute to the gradual weakening and wearing away of cuticle scales.6 , 25, 33 The distal, oldest segments of hair primarily are affected, because here the cuticle has endured the degradative forces for the longest time. Patients should cut off the affected ends and comb and brush the hair as gently and as little as possible. The use of cream rinses and protein hair conditioners is helpful and, with proper hair care, the condition is easily controlled. PILI TORTI. Pili torti is a hair-shaft defect in which the fragile hair is flattened and twisted on its own axis (Fig. 5). Twisted, fragile hair occurs in several clinical syndromes, two of which are listed here. Classic pili torti. Classic pili torti is part of a clinical syndrome which represents a form of ectodermal dysplasia. It occurs in females more frequently than in males, and the majority are blond. The pattern of inheritance is variable. By the age of two or three years and occasionally later, the hair is replaced by brittle hair with a strikingly
Figure 4. Proximal trichorrhexis nodosa. The short hair length is due to marked hair fragilityand hair breakage.
312
Figure 5. York, 1978.)
VERA
H.
PRICE
Pili torti in a hair mount. (To be published by Gustav Fischer Verlag, New
spangled appearance. 34 Other ectodermal defects are often present and include keratosis pilaris, dental abnormalities, dystrophic nails, and corneal opacities. A number of patients with pili torti have sensorineural hearing loss (cochlear type), and children with this anomaly should have early auditory testing. 32 The hair may improve at puberty or remain unchanged throughout life. Pili torti with copper deficiency: trichopoliodystrophy. Trichopoliodystrophy, or Menkes' steely-hair syndrome, is a progressive neurodegenerative disorder which affects infant males and is characterized by pili torti, seizures, psychomotor retardation, growth failure, and death by the age of four years. Widespread arterial degeneration and scorbutic bone changes are present, and all features can be explained by faults in copper-dependent enzymes,u The etiology of this sexlinked recessive disease appears to be a net intestinal malabsorption of copper, with low levels of serum, hepatic, and brain copper,11, 12 The hair is white, dull, stands on end, and looks and feels like steel woolj13 microscopically, it shows pili torti. The hair depigmentation reflects a defect in tyrosinase metabolism, and the marked hair fragility is due to impaired disulfide bond formation in the hair keratin fibers. The hair provides an important clue to this rapidly progressive fatal disease. The differential diagnosis of mentally defective infants and children with peculiar hair includes trichopoliodystrophy and argininosuccinicaciduria. The diagnostic work-up should include a hair-mount examination, serum copper and copper oxidase determinations (using copper-free heparin), and paper chromatographic estimation of blood and urine amino acids. At present, the early institution of intravenous copper therapy in trichopoliodystrophy, before extensive neurologic damage has occurred, offers some limited hope for these children.5 , 17
DISORDERS OF THE HAIR IN CHILDREN
313
Figure 6. Pili annulati viewed by reflected light, showing characteristic bright bands. (Reprinted by permission, Arch. Dermatol., 98:640-647, 1968. Copyright 1968, American Medical Association.)
Hair-Shaft Anomalies Without Increased Hair Fragility PILI ANNULATI. In pili annulati, the hair shafts show striking bright and dark bands when viewed by reflected light (Fig. 6). The bright bands are caused by light scattered from periodically occurring clusters of abnormal, air-filled cavities within the hair.30 There are no abnormal laboratory findings. Treatment is not required because the banding is attractive and the hair is strong. PSEUDO PILI ANNULATI. Pseudo pili annulati is an unusual variant of normal hair, in which striking bright bands are seen at intervals along the hair shaft (Fig. 7). The banding is a superficial optical effect due to the reflection and refraction of light by the flattened, twisted surface of the hair.31 This banding is conspicuous only in blond hair, as brunet hair, even if similarly twisted, absorbs most of the incident light. WOOLLY HAIR. Occasionally, white individuals are born with woolly hair that is tight, curly, and distinctly different from that of nonaffected members of the family. In childhood, the hair is often impossible to brush,19 The condition may improve in adulthood. Three groups have been differentiated clinically: 19 (1) The woolly hair is in herited as an autosomal dominant trait; hair color shows a normal variation and body hair is normal. (2) The woolly hair is inherited as an autosomal recessive trait or may occur sporadically; scalp hair has a distinctive bleached appearance (Fig. 8A), and body hair is unusually short and pale. (3) The woolly hair nevus affects only a part of the
314
VERA
H.
PRICE
Figure 7. Pseudo pili annulati viewed by reflected light, showing bright bands. (Reprinted by permission, Arch. Dermatol., 102:354-358, 1970. Copyright 1970, American Medical Association.)
scalp (Fig. 8B) with distinctive curly hair that is lighter in color than the normal hair; the condition occurs sporadically.
ALOPECIA AREATA This common condition is characterized by the sudden appearance of sharply defined, round or oval patches of complete hair loss (Fig. 9A). The scalp is most commonly involved, but any hair-bearing skin may be affected (Fig. 9B). Children and younger persons are more frequently affected than adults, although the condition occurs at all ages. The process may be limited to a few patches or it may progress to
Figure 8. A, Woolly hair. B, Woolly hair nevus. (To be published by Gustav Fischer Verlag, New York, 1978.)
DISORDERS OF THE HAIR IN CHILDREN
315
Figure 9. A, Alopecia areata. B, Alopecia totalis. Note missing right eyebrow.
alopecia totalis, in which all scalp hair is lost (Fig. 9B), or to alopecia universalis, in which all hair on the entire body is lost. In general, children tend to have more extensive involvement and progress to alopecia totalis more frequently than adults. The course is variable and unpredictable; in general, when the process is limited to a few patches, the prognosis is good, and when the process is extensive, total, or universal, the prognosis for complete and permanent recovery is poor. Alopecia areata is often associated with certain autoimmune conditions in the patient or his family. These include Hashimoto's thyroiditis,IO vitiligo,9 and collagen disease. There is an increased incidence of thyroid disease of all types lO and of atopy26 in these patients. Even patients with no clinical signs of autoimmune disease may show an increased incidence of organ-specific autoantibodies, such as antibodies against thyroglobulin, parietal cells, and adrenal cells. 20 Relatives of patients have an increased incidence of diabetes mellitus. 10 Although it is premature to classify alopecia areata as an autoimmune process, this may prove to be the case. In children with one or two patches, the hair may regrow spontaneously. However, it is preferable that all children be treated with local corticosteroids. Intralesional injection of corticosteroids is the treatment of choice in children old enough to tolerate it; the use of a 3D-gauge needle and light refrigeration with ethyl chloride spray makes this method quite acceptable. In younger children, topical corticosteroids such as fiuocinonide, are applied under a shower cap overnight, or after a shower.
TRICHOTILLOMANIA In this condition, the patient compulsively pulls out or breaks off his hair. The scalp is most commonly involved, but other hairy areas such as the eyebrows and eyelashes may also be affected. The affected patches have irregularly shaped, angular outlines and, within the
316
VERA
H.
PRICE
Figure 10. A. Trichotillomania. Note irregular shape of affected area and broken hairs of varying lengths. B, Extensive trichotillomania. Only hair over most inaccessible portions of occipital scalp has been spared.
patches, the hair is short and broken off at varying lengths (Fig. lOA). In more severe cases, the patient compulsively breaks off the hair on the entire scalp except that on the most inaccessible portions of the occipital scalp; this produces a characteristic clinical picture (Fig. lOB).
In many children, the condition may merely be a tic analogous to nail-biting and may require no special attention. In others, bringing the habit to the child's attention and reassuring him is enough to stop the tic. However, the need of each child for psychiatric evaluation should be individually considered.
TRACTION AND TRAUMATIC ALOPECIA Hair styles may cause traction alopecia if excessive tension is applied to the hair for long periods. Tight ponytails and braids (Fig. 11) and the revived custom of "corn-rowing" are examples of such hair styles. Releasing the tension on the hair reverses the problem in most cases, but occasionally, when traction has been prolonged, alopecia may be permanent. Children may pull out hanks of hair from each other during play. In this situation, it is helpful to know that regrowth may be delayed for several months, because, when growing follicles are forcibly avulsed, they take about three months to return to the growing phase. Friction can cause breakage of the hair shaft, and infants often have localized areas of hair loss from the friction of rubbing the scalp on the bed.
DISORDERS OF THE HAIR IN CHILDREN
317
Figure 11. Traction alopecia and folliculitis resulting from prolonged traction of tight braids.
INFECTIONS The key features of fungal infections of the scalp are patchy, partial hair loss, with broken hairs and scaling (Fig. 12). Without a high index of suspicion, tinea capitis is often misdiagnosed as trichotillomania or alopecia areata. The clinical appearance of tinea capitis varies with the species of dermatophyte involved and with the degree of host resistance. Some patients show only a few patchy, gray areas with broken hairs and mild scaling, whereas others have an acute, severe inflammatory process that affects large areas of the scalp. Diagnosis is made by examination of the hair with a Wood's light, by microscopic examination of broken hairs in a potassium hydroxide mount, and by culture of the broken hairs. Treatment with griseofulvin
Figure 12. Tinea capitis, showing characteristic gray patch with broken hairs and scaling.
318
VERA
H.
PRICE
"
is very satisfactory. Depending on the dermatophyte involved, human and animal contacts must also be found and treated. Bacterial infections such as impetigo, furuncles, and ecthyma can involve the scalp. If the process is superficial, then any hair loss is temporary. If, however, the follicle is destroyed by the inflammatory process, a permanent scarring alopecia is produced. Viral infections such as herpex simplex, zoster, varicella, and the common wart may also affect the scalp; here again, the hair loss may be temporary or permanent, depending on whether the hair follicle is destroyed.
TOXIC ALOPECIA Cancer therapeutic drugs may cause extensive scalp hair loss. These agents cause a temporary arrest of mitotic activity in the matrix region of growing hairs; this results in constriction of the hair shaft and subsequent hair breakage. The hair loss begins about one to three weeks after systemic administration of one of these drugs is started, and 80 to 90 per cent of the hairs are affected. All categories of cancer therapeutic agents produce this hair loss, including the antimetabolites (such as methotrexate, 6-mercaptopurine, or 5-fluorouracil), the alkylating agents (such as nitrogen mustard, chlorambucil, cyclophosphamide, or thiotepa), and cell poisons (such as antinomycin D, colchicine, or vinblastine). Treatment is unnecessary because the hair recovers promptly after the pharmacologic activity of the drug ceases, even after repeated therapeutic courses. Nonspecific toxic alopecia may be caused by heavy metals such as lead and arsenic, and by many drugs, including trimethadione, thallium, heparin, coumarin, triparanol, thiourea, carbamazepine, and lithium carbonate. In most cases, the hair regrows when the offending drug is stopped.
NUTRITIONAL, METABOLIC HAIR LOSS In general, a wide variation of dietary customs is compatible with normal hair growth, and nutritional deprivation must be severe before hair growth is affected. Because hair keratin is composed almost entirely of fibrous proteins, an adequate dietary protein intake is required for normal hair growth. In situations when dietary protein plus mobilized body protein are insufficient to meet body requirements, the low priority of hair growth for available protein results in increased numbers of hairs entering the telogen phase as a protein-sparing mechanism. 2 As a result, there is a marked increase in hair shedding from the increased numbers of telogen follicles. Such a situation occurs during crash dieting if protein intake is inadequate. 2 • 16 In the more extreme examples of kwashiorkor and marasmus, hair is not only shed but also changed morphologically; in fact, it is used as a public health tool in the assessment of protein-calorie malnutrition in the field. 3 The severe malnutrition that occurs in celiac disease similarly affects the hair.
DISORDERS OF THE HAIR IN CHILDREN
319
Vitamin A can cause hair loss if taken in either excessive or inadequate amounts. In general, the daily ingestion of surplus vitamins does not produce healthier, stronger hair, as is frequently claimed in advertisements. In acrodermatitis enteropathica, alopecia accompanies the severe diarrhea and dermatitis. Following the discovery that this autosomal recessive condition is due to zinc deficiency, the administration of zinc orally has reversed all the signs and symptoms, including the hair loss.24 HORMONAL INFLUENCES ON HAIR GROWTH Hormones modify both the hair cycle and the caliber of the hair that is produced. The duration of the growing and resting phase of the cycle is particularly influenced by excess or deficiency of glucocorticoids or thyroid hormone. as These hormones may either accelerate or delay the initiation of the anagen phase, and hence may determine the number of hairs in anagen and telogen. In both hypothyroidism and hyperthyroidism, the ratio of telogen to anagen hairs is increased. Disturbances of the hair cycle are usually reversed when the hormonal influence is corrected. Vellus hair may become terminal hair, and terminal hair may become vellus, as a result of hormonal stimulation or by genetically determined responses of the follicular target organs. Androgens and growth hormone are usually the hormones responsible for such changes in hair caliber.as In virilizing syndromes, vellus hair changes into coarse terminal hair in certain body regions which are determined by age and by the genetic constitution. In androgenetic alopecia (common baldness), terminal hair gradually becomes miniaturized into vellus hair in certain genetically predisposed follicles on the scalp under the influence of normal levels of circulating androgen. 29 Changes in hair caliber are usually not completely reversed, in some cases not at all, by removal of the hormonal stimulus. REFERENCES 1. Allan, J. D., Cusworth, D. c., Dent, C. E., et al.: A disease, probably hereditary, characterised by severe mental deficiency and a constant gross abnormali-ty of aminoacid metabolism. Lancet, 1 :182, 1958. 2. Blackburn, G. L., Bristrian, B. R., and Hoag, C.: Hair loss with rapid weight loss. J.A.M.A., 236:252,1976. 3. Bradfield, R. B., and Bailey, M. A.: Hair root response to protein undernutrition. In Montagna, W., and Dobson, R. L. (eds.): Advances in Biology of Skin. Oxford, Pergamon Press, 1969, p. 109. 4. Brenton, D. P., Cusworth, D. C., Hartley, S., et al.: Argininosuccinicaciduria: Clinical, metabolic and dietary study. J. Ment. Defic. Res., 18:1,1974. 5. Bucknall, W. E., Haslam, R. H. A., and Holtzman, N. A.: Kinky hair syndrome: Response to copper therapy. Pediatrics, 52:653, 1973. 6. Chernosky, M. E., and Owens, D. W.: Trichorrhexis nodosa: Clinical and investigative studies. Arch. Dermatol., 94:577, 1966. . 7. Comaish, S.: Metabolic disorders and hair growth. Br. J. DermatoL, 84:83,1971. 8. Crounse, R. G.: Trichorrhexis nodosa and amino acid metabolism. Arch. DermatoL, 86:391, 1962.
320
VERA
H.
PRICE
9. Cunliffe. W. J., Hall, R, Newell, D. J., et al.: Vitiligo, thyroid disease and autoimmunity. Br. J. Dermatol., 80:135,1968. 10. Cunliffe, W. J., Hall, R, Stevenson, C. J., et al.: Alopecia areata, thyroid disease and autoimmunity. Br. J. Dermatol., 81 :877, 1969. 11. Danks, D. M.: Steely hair, mottled mice and copper metabolism. New Engl. J. Med., 293:1147,1975. 12. Danks, D. M., Campbell, P. E., Stevens, B. J., et al.: Menkes' kinky hair syndrome: An inherited defect in copper absorption with widespread effects. Pediatrics, 50: 188, 1972. 13. Danks, D. M., Cartwright, E., and Stevens, B. J.: Menkes' steely-hair (kinky-hair) disease. Lancet, 1 :891, 1973. 14. Efron, M. L., and Hoefnagel, D.: Argininosuccinic acid in monilethrix. Lancet, 1 :321, 1966. 15. Flesch, P.: Hair growth. In Rothman, S. (ed.): Physiology and Biochemistry of the Skin. Chicago, University of Chicago Press, 1954, p. 601. 16. Goette, D. K., and Odom, R. B.: Alopecia in crash dieters. J.A.M.A., 235:2622,1976. 17. Grover, W. D., and Scrutton, M. C.: Copper infusion therapy in trichopoliodystrophy. J. Pediat., 86:216,1975. 18. Hersle, K.: Netherton's' disease and ichthyosis linearis circumflexa: Report of a case and review of the literature. Acta Derm. Venereol. (Stockh.), 52:298,1972. 19. Hutchinson, P. E., Cairns, R J., and Wells, R S.: Woolly hair; Clinical and general aspects. Trans. St. John's Hosp. Derm. Soc. (Lond.), 60:160,1974. 20. Kern, F., Hoffman, W. H., Hambrick, G. W., Jr., et. al.: Alopecia areata: Immunologic studies and treatment with prednisone. Arch. Dermatol, 107:407,1973. 21. Levin, B., Mackay, H. M. M., and Oberholzer, V. G.: Argininosuccinic aciduria: An inborn error of amino acid metabolism. Arch. Dis. Child, 36:622, 1961. 22. Mackee, G. M., and Rosen, I.: Monilethrix: A clinical and histological study, with a report of six cases and a review of the literature. J. Cutan. Dis., 34:444, 1916. 23. Mevorah, B., Frenk, E., and Brooke, E. M.: Ichthyosis linearis circumflexa Comel: A clinico-statistical approach to its relationship with Netherton's syndrome. Dermatologica, 149:201, 1974. 24. Neldner, K. H., and Hambidge, K. M.: Zinc therapy of acrodermatitis enteropathica. New Engl. J. Med., 292:879,1975. 25. Papa, C. M., Mills, O. H., Jr., and Hanshaw, W.: Seasonal trichorrhexis nodosa: Role of cumulative damage in frayed hair. Arch. Dermatol., 106:888, 1972. 26. Penders, A. J. M.: Alopecia areata and atopy. Dermatologica, 136:395,1968. 27. Porter, P. S., and Lobitz, W. C., Jr.: Human hair: A genetic marker. Br. J. Dermatol., 83:225.1970. 28. Price, V. H.: Office diagnosis of structural hair anomalies. Cutis, 15:231,1975. 29. Price, V. H.: Testosterone metabolism in the skin: A review of its function in androgenetic alopecia, acne vulgaris, and idiopathic hirsutism including recent studies with antiandrogens. Arch. Dermatol., 111: 1496, 1975. 30. Price, V. H., Thomas, R S., and Jones, F. T.: Pili annulati: Optical and electron microscopic studies. Arch. Dermatol., 98:640, 1968. 31. Price, V. H., Thomas, R. S., and Jones, F. T.: Pseudopili annulati: An unusual variant of normal hair. Arch. Dermatol., 102:354, 1970. 32. Robinson, G. C., and Johnston, M. M.: Pili torti and sensory neural hearing loss. J. Pediat., 70:621, 1967. 33. Robinson, V. N. E.: A study of damaged hair. J. Soc. Cosmet. Chem., 27:155,1976. 34. Ronchese, F.: Twisted hairs (pili torti). Arch. Derm. Syph., 26:98,1932. 35. Rook, A.: Endocrine influences on hair growth. Br. Med. J., 1 :609,1965. 36. Sanderson, K. V., and Hall-Smith, P.: Tonsure trichotillomania. Br. J. Dermatol., 82:343, 1970. 37. Solomon, L. M., and Esterly, W. B.: Neonatal Dermatology. Philadelphia, W. B. Saunders Co., 1973, p. 191. 38. Stevanovic, D. V.: Multiple defects of the hair shaft in Netherton's disease: Association with ichthyosis linearis circumflexa. Br. J. Dermatol, 81 :851, 1969. 39. Summerly, R, and Donaldson, E. M.: Monilethrix: A family study. Br. J. Dermatol., 74:387, 1962. 40. Tomlinson, S., and Westall, R G.: Argininosuccinic aciduria: Argininosuccinase and arginase in human blood cells. Clin. Sci., 26:261, 1964. 41. Wilkinson, R D., Curtis, G. H., and Hawk, W. A.: Netherton's disease: Trichorrhexis invaginata (bamboo hair). congenital ichthyosiform erythroderma and the atopic diathesis. A histopathologic study. Arch. Dermatol., 89:46, 1964. Department of Dermatology Kaiser-Permanente Medical Center 2200 O'Farrell Street San Francisco, California 94115
Disorders of the Hair in Children Vera H. Price, M.D., FR.C'p. (C)*
The assessment of an infant or child with hair loss involves taking a detailed history and performing a careful clinical examination, and microscopic hair examination in many instances. In taking the history, it is important to determine first whether the hair is coming out with the roots attached, as in alopecia areata, or whether the hair is breaking off at some point distal to the roots, as in trichotillomania or tinea capitis. Other important aspects of the history include the duration of the hair disorder, drug intake, mental state, physical development (including state of teeth, nails, eyes, and presence of heat intolerance), past medical history, hair style and hair care and cosmetics, and family history of hair problems. In the clinical examination, the hair texture, length, style, and pattern and distribution of hair loss are noted. A "pull test" is useful in determining whether the hair is shedding excessively, as in alopecia areata (around the margins of active lesions) or in some of the congenital alopecias. The test is done by grasping 8 to 10 closely grouped hairs near and scalp with the thumb, index, and middle fingers, and applying traction as the fingers are pulled firmly and slowly away from the scalp. Normally, 0 to 2 hairs are pulled out by this method. If excessive shedding is present 4 to 6 or more hairs are easily and painlessly pulled out. Another useful test is to examine the hair tips against a contrasting background to see if they are tapered or broken. The scalp itself is assessed for the presence of scaling, inflammation, cradle cap, infection, and scarring. Hair elsewhere on the body is examined to determine if there is too much or too little in other sites. Teeth, nails, and the mental state are evaluated, and the presence of absence of sweating is noted. Light microscopic examination of a hair mount frequently provides helpful information. When a fungus infection is suspected, a few short, broken hairs are mounted in potassium hydroxide, which dissolves the keratin and allows easy visualization of fungal elements. When a hair-shaft anomaly is suspected and one wishes to examine the ':'Associate Clinical Professor, Department of Dermatology, University of California, San Francisco; Department of Dermatology, Kaiser-Permanente Medical Center, San Francisco, California
Pediatric Clinics of North America- Vol. 25, No.2, May 1978
305
306
VERA
H.
PRICE
hair shaft itself, balsam, Permount, or synthetic resin are used because in these media, the hair is seen sharply and without surface light scatter. In order to understand normal hair growth as well as the response of hair to various insults, it is important to understand the human hair growth cycle. Every hair follicle has a regular period of activity and another of rest. During the growth phase, called the anagen phase, the cells in the hair matrix are actively dividing and producing a growing hair. The anagen phase in the human scalp lasts 2 to 6 years, or approximately 1000 days. The anagen phase is followed by the resting period, called the telogen phase, during which mitotic activity in the hair matrix ceases and the hair stops growing. The telogen phase lasts about 3 months, or approximately 100 days. The old resting hair is eventually pushed out of the follicle by the new growing hair coming up from below, and is shed. There are approximately 100,000 hairs on the average human scalp. About 90 per cent of these hairs are in the anagen phase, and about 10 per cent are in the telogen phase. As follicular activity is not synchronized in adjacent follicles, the 100 hairs that represent the average daily hair loss come from follicles allover the scalp, and this daily shedding is not particularly noticed by most individuals. Human hair grows approximately 1 cm in 1 month, which represents a production of about 30 meters of hair per day! Present knowledge allows the classification of disorders of the hair in children detailed below: I. Physiologic hair loss Shedding of the newborn Temporal recession at puberty II. Congenital alopecias, hypotrichosis, hypertrichosis III. Structural hair shaft anomalies A. With increased hair fragility 1. Monilethrix 2. Bamboo hair (trichorrhexis invaginata) 3. Trichorrhexis nodosa a. congenital i. trichorrhexis congenita ii. with argininosuccinicaciduria b. acquired i. proximal trichorrhexis nodosa ii. distal trichorrhexis nodosa 4. Pili torti a. classic pili torti b. with copper deficiency; trichopoliodystrophy B. Without increased hair fragility 1. Pili annulati 2. Pseudo pili annulati 3. Woolly hair IV. Alopecia areata V. Trichotillomania VI. Traction and traumatic alopecia VII. Infections VIII. Toxic alopecia IX. Nutritional, metabolic hair loss X. Hormonal influence on hair growth
DISORDERS OF THE HAIR IN CHILDREN
307
PHYSIOLOGIC HAIR LOSS Shedding of the Newborn Lanugo hair is the first silky hair made by hair follicles in utero, and is -present over the entire fetus. It is normally shed in utero and replaced by vellus hair in all regions except the scalp, eyebrows, and eyelashes, where the lanugo is replaced by terminal hair. The second growth begins prenatally in the sixth to eighth months and continues postnatally.I5 The "secondary hair" has a short growing phase and is shed within the first year of life. This physiologic shedding is temporary and is no cause for concern. The shed hair is replaced by thicker, longer, and darker hair. Temporal Recession at Puberty The frontal hairline in children is straight. In late puberty, increased androgen levels cause the transition from terminal to vellus hair at the frontal hairline, changing the hairline to an "M" shape. This change occurs in both sexes. It does not occur in eunuchs.
CONGE NIT AL ALOPECIAS, HYPOTRICHOSIS, HYPERTRICHOSIS A variety of congenital and hereditary disorders is associated with abnormalities of the hair. The hair may be totally absent (alopecia), unusually sparse (hypotrichosis), or overabundant in its growth (hypertrichosis).37 In rare instances, congenital alopecia occurs as an isolated defect, inherited as an autosomal recessive trait. In most instances, however, the hair abnormality - which may include changes in density, color, caliber, and fragility - is only part of a complex congenital or hereditary disorder. There is as yet no satisfactory way to classify this diverse group of conditions. Some are associated with other ectodermal defects (i.e., hidrotic and anhidrotic ectodermal dysplasia), some with skeletal defects (Le., cartilage-hair hypoplasia, oral-facialdigital syndrome), some with amino acid disorders (i.e., phenylketonuria, homocystinuria), and some with chromosomal defects (Le., Cornelia de Lange syndrome, Down's syndrome).27
STRUCTURAL HAIR-SHAFT ANOMALIES The structural hair-shaft anomalies are an important group of disorders which may, in some instances, provide a clue to widespread pathology such as an inborn error of metabolism. Because each anomaly has a highly distinctive morphology, the diagnosis is easily made in the office with a microscopic hair-mount examination. Hair-shaft disorders may be divided into two groups: those that cause increased hair fragility and breakage, and those that do not cause increased hair fragility and breakage.
308
VERA
H.
PRICE
Figure 1. Monilethrix in a hair mount. (From Price, V. H.: Office diagnosis of structural hair anomalies. Cutis, 15:231, 1975, with permission.)
Hair-Shaft Anomalies with Increased Hair Fragility MONILETHRIX. Monilethrix is a distinctive, rare hair defect inherited as a simple dominant trait22 , 39 and named after the resemblance of the affected hair shaft to a string of beads. In infancy, the hair breaks, leaving the scalp covered with broken hair 0.5 to 2.5 cm long. The scalp is the main site affected, but hair in other areas may also be affected in various degrees. A hair mount shows the distinctive "nodes," which have the diameter of normal hair and are medullated, alternating rhythmically with the "internodes," which are constricted, nonmedullated, and are the sites of fracture (Fig. 1). Keratosis pilaris is always associated with monilethrix and usually occurs on the upper back and shoulders. Occasionally, there are also other ectodermal defects, such as brittle nails, decreased visual fields, juvenile cataracts, and dental lesions. The etiology is unknown. Monilethrix is not associated with argininosuccinicaciduria. 7 ,14 There is no known treatment, but the condition may improve at puberty, with pregnancy, or with oral contraceptives. BAMBOO HAIR (TRICHORRHEXIS INVAGINATA). Bamboo hair (trichorrhexis invaginata) is found in a rare, ectodermal genodermatosis known as "Netherton's disease," which combines ichthyosiform skin changes, the hair-shaft anomaly, and frequently but not invariably, the atopic state. The distinctive hair defect resembles the ball-and-cup joints of bamboo (Fig. 2). The ichthyosiform eruption in the majority of patients is consistent with ichthyosis linearis circumflexa, which features migratory, serpiginous, erythematous, scaling lesions that have a characteristic double-edged scale at the advancing borders.1B,23 In a small number of patients, other forms of ichthyosis have included congenital ichthyosiform erythroderma, sex-linked ichthyosis, and ichthyosis vulgaris. Present evidence suggests an autosomal recessive inheritance; about 60 per cent of those affected are females. 23 Etiology is unknown, but the condition represents a severe disturbance of the keratinization process. Shortly after birth, redness and scaling affect the face and other areas of the body. In the following months or years, the characteristic features of the ichthyosiform process appear. The hair defect appears in infancy, and all hair is affected to some degree. Scalp hair is dry and dull, and so fragile (because of the abnormal invaginations along the shaft) that the hair cannot achieve a
DISORDERS OF THE HAIR IN CHILDREN
309
normal length. The bamboo joints are easily seen in a hair mount; the cup portion of the defect is proximal, and the ball portion, distal (Fig. 2). Hair shafts also show twisting of the shaft, changes in caliber of the shaft, and tulip-like forms.38 Many patients have an atopic diathesis such as flexural eczema, asthma, allergic rhinitis, angioneurotic edema, urticaria, or anaphylactoid reactions. Nb constant laboratory abnormalities have been found. Intermittent aminoaciduria was found in a few patients,18 and hypogammaglobulinemia was present in one patient. 41 Potent topical corticosteroid creams help the skin temporarily, as does the Goeckerman routine. The skin may improve somewhat at puberty, but in general the cutaneous changes persist. The scalp hair tends to improve with age. TRICHORRHEXIS N ODOSA. Trichorrhexis nodosa is the most common of all hair-shaft anomalies. The name refers to the appearance of the defect-a "node"-which in the light microscope is seen to be a hair-shaft fracture in which the individual cortical cells splay out, resembling the ends of two brushes pushed into one another (Fig. 3). Trichorrhexis congenita. In trichorrhexis congenita, the hair-shaft fragility is often the only abnormal clinical feature. The condition may be familial. Scalp hair breaks easily and leaves short, broken ends and areas of partial alopecia. Occasionally, tooth and nail changes also are present.
Figure 2. York, 1978.)
Bamboo hair in a hair mount. (To be published by Gustav Fischer Verlag, New
310
VERA
H.
PRICE
Figure 3. Trichorrhexis nodosa in a hair mount. (To be published by Gustav Fischer Verlag, New York, 1978.)
Trichorrhexis nodosa in mentally retarded infants with argininosuccinicaciduria. This rare syndrome is an example of mental retardation associated with an inborn error of metabolism. 21o 40 Since its recognition in 1958,1 about 20 families have been reported. 4 Mental retardation is evident in the first two years of life, and large amounts of argininosuccinic acid are found in the urine, blood, and cerebrospinal fluid. Many, but not all, of these children have dry, brittle, stubbly hair which shows trichorrhexis nodosa. Normally, argininosuccinic acid, an intermediate in the Krebs-Henseleit urea cycle, is split by the enzyme argininosuccinase to form arginine and fumaric acid. This cleavage enzyme is not present in the blood cells of affected infants; argininosuccinic acid therefore accumulates in the blood and cerebrospinal fluid, and is excreted in the urine. Because normal human hair contains 7.5 to 10.5 per cent of arginine by weight,S the disturbed metabolism of arginine in this condition may lead to faulty keratin formation and structural weakness of hair. The hair defect, when present, is an important diagnostic clue to this systemic disease, and a hair mount should be studied in any infant with mental retardation and peculiar hair. The differential diagnosis includes trichopoliodystrophy (Menkes' steely-hair syndrome). Proximal trichorrhexis nodosa. This common condition, seen only in the black population, presents a distinctive clinical picture.2s Patients complain that their hair will not grow longer than a few centimeters above the scalp (Fig. 4). The inability to grow long hair is due to extreme hair fragility, which causes hair breakage over large portions of the scalp. Frequently, other family members also have a similar problem with short hair. The cause appears to be a genetic predisposition combined with trauma from hair straightening, tight caps, or harsh brushing and combing. The hair is so fragile that a firm lengthwise tug separates a hair into shorter segments. A hair mount of these short, broken segments shows longitudinal splitting, a defective shaft, and trichorrhexis nodosa. The hair breakage usually ceases in
DISORDERS OF THE HAIR IN CHILDREN
311
two to four years if all hair-straightening procedures and vigorous grooming habits are stopped. The use of protein hair conditioners and a wide-toothed, round-tipped comb is recommended. Distal trichorrhexis nodosa. Distal trichorrhexis nodosa is a common condition that occurs in otherwise normal hair as a result of acquired, cumulative cuticular damage. The condition is seen primarily in white and Oriental persons as white specks along the distal 2 to 4 inches of hair.6 The affected hair looks faded and dull and breaks off at various lengths, giving the ends a skimpy appearance. In a hair mount, the white specks show typical fractures of trichorrhexis nodosa (Fig. 3).
Vigorous combing and brushing, prolonged sun exposure, chemical processing, repeated salt-water bathing, and frequent shampooing all contribute to the gradual weakening and wearing away of cuticle scales.6 , 25, 33 The distal, oldest segments of hair primarily are affected, because here the cuticle has endured the degradative forces for the longest time. Patients should cut off the affected ends and comb and brush the hair as gently and as little as possible. The use of cream rinses and protein hair conditioners is helpful and, with proper hair care, the condition is easily controlled. PILI TORTI. Pili torti is a hair-shaft defect in which the fragile hair is flattened and twisted on its own axis (Fig. 5). Twisted, fragile hair occurs in several clinical syndromes, two of which are listed here. Classic pili torti. Classic pili torti is part of a clinical syndrome which represents a form of ectodermal dysplasia. It occurs in females more frequently than in males, and the majority are blond. The pattern of inheritance is variable. By the age of two or three years and occasionally later, the hair is replaced by brittle hair with a strikingly
Figure 4. Proximal trichorrhexis nodosa. The short hair length is due to marked hair fragilityand hair breakage.
312
Figure 5. York, 1978.)
VERA
H.
PRICE
Pili torti in a hair mount. (To be published by Gustav Fischer Verlag, New
spangled appearance. 34 Other ectodermal defects are often present and include keratosis pilaris, dental abnormalities, dystrophic nails, and corneal opacities. A number of patients with pili torti have sensorineural hearing loss (cochlear type), and children with this anomaly should have early auditory testing. 32 The hair may improve at puberty or remain unchanged throughout life. Pili torti with copper deficiency: trichopoliodystrophy. Trichopoliodystrophy, or Menkes' steely-hair syndrome, is a progressive neurodegenerative disorder which affects infant males and is characterized by pili torti, seizures, psychomotor retardation, growth failure, and death by the age of four years. Widespread arterial degeneration and scorbutic bone changes are present, and all features can be explained by faults in copper-dependent enzymes,u The etiology of this sexlinked recessive disease appears to be a net intestinal malabsorption of copper, with low levels of serum, hepatic, and brain copper,11, 12 The hair is white, dull, stands on end, and looks and feels like steel woolj13 microscopically, it shows pili torti. The hair depigmentation reflects a defect in tyrosinase metabolism, and the marked hair fragility is due to impaired disulfide bond formation in the hair keratin fibers. The hair provides an important clue to this rapidly progressive fatal disease. The differential diagnosis of mentally defective infants and children with peculiar hair includes trichopoliodystrophy and argininosuccinicaciduria. The diagnostic work-up should include a hair-mount examination, serum copper and copper oxidase determinations (using copper-free heparin), and paper chromatographic estimation of blood and urine amino acids. At present, the early institution of intravenous copper therapy in trichopoliodystrophy, before extensive neurologic damage has occurred, offers some limited hope for these children.5 , 17
DISORDERS OF THE HAIR IN CHILDREN
313
Figure 6. Pili annulati viewed by reflected light, showing characteristic bright bands. (Reprinted by permission, Arch. Dermatol., 98:640-647, 1968. Copyright 1968, American Medical Association.)
Hair-Shaft Anomalies Without Increased Hair Fragility PILI ANNULATI. In pili annulati, the hair shafts show striking bright and dark bands when viewed by reflected light (Fig. 6). The bright bands are caused by light scattered from periodically occurring clusters of abnormal, air-filled cavities within the hair.30 There are no abnormal laboratory findings. Treatment is not required because the banding is attractive and the hair is strong. PSEUDO PILI ANNULATI. Pseudo pili annulati is an unusual variant of normal hair, in which striking bright bands are seen at intervals along the hair shaft (Fig. 7). The banding is a superficial optical effect due to the reflection and refraction of light by the flattened, twisted surface of the hair.31 This banding is conspicuous only in blond hair, as brunet hair, even if similarly twisted, absorbs most of the incident light. WOOLLY HAIR. Occasionally, white individuals are born with woolly hair that is tight, curly, and distinctly different from that of nonaffected members of the family. In childhood, the hair is often impossible to brush,19 The condition may improve in adulthood. Three groups have been differentiated clinically: 19 (1) The woolly hair is in herited as an autosomal dominant trait; hair color shows a normal variation and body hair is normal. (2) The woolly hair is inherited as an autosomal recessive trait or may occur sporadically; scalp hair has a distinctive bleached appearance (Fig. 8A), and body hair is unusually short and pale. (3) The woolly hair nevus affects only a part of the
314
VERA
H.
PRICE
Figure 7. Pseudo pili annulati viewed by reflected light, showing bright bands. (Reprinted by permission, Arch. Dermatol., 102:354-358, 1970. Copyright 1970, American Medical Association.)
scalp (Fig. 8B) with distinctive curly hair that is lighter in color than the normal hair; the condition occurs sporadically.
ALOPECIA AREATA This common condition is characterized by the sudden appearance of sharply defined, round or oval patches of complete hair loss (Fig. 9A). The scalp is most commonly involved, but any hair-bearing skin may be affected (Fig. 9B). Children and younger persons are more frequently affected than adults, although the condition occurs at all ages. The process may be limited to a few patches or it may progress to
Figure 8. A, Woolly hair. B, Woolly hair nevus. (To be published by Gustav Fischer Verlag, New York, 1978.)
DISORDERS OF THE HAIR IN CHILDREN
315
Figure 9. A, Alopecia areata. B, Alopecia totalis. Note missing right eyebrow.
alopecia totalis, in which all scalp hair is lost (Fig. 9B), or to alopecia universalis, in which all hair on the entire body is lost. In general, children tend to have more extensive involvement and progress to alopecia totalis more frequently than adults. The course is variable and unpredictable; in general, when the process is limited to a few patches, the prognosis is good, and when the process is extensive, total, or universal, the prognosis for complete and permanent recovery is poor. Alopecia areata is often associated with certain autoimmune conditions in the patient or his family. These include Hashimoto's thyroiditis,IO vitiligo,9 and collagen disease. There is an increased incidence of thyroid disease of all types lO and of atopy26 in these patients. Even patients with no clinical signs of autoimmune disease may show an increased incidence of organ-specific autoantibodies, such as antibodies against thyroglobulin, parietal cells, and adrenal cells. 20 Relatives of patients have an increased incidence of diabetes mellitus. 10 Although it is premature to classify alopecia areata as an autoimmune process, this may prove to be the case. In children with one or two patches, the hair may regrow spontaneously. However, it is preferable that all children be treated with local corticosteroids. Intralesional injection of corticosteroids is the treatment of choice in children old enough to tolerate it; the use of a 3D-gauge needle and light refrigeration with ethyl chloride spray makes this method quite acceptable. In younger children, topical corticosteroids such as fiuocinonide, are applied under a shower cap overnight, or after a shower.
TRICHOTILLOMANIA In this condition, the patient compulsively pulls out or breaks off his hair. The scalp is most commonly involved, but other hairy areas such as the eyebrows and eyelashes may also be affected. The affected patches have irregularly shaped, angular outlines and, within the
316
VERA
H.
PRICE
Figure 10. A. Trichotillomania. Note irregular shape of affected area and broken hairs of varying lengths. B, Extensive trichotillomania. Only hair over most inaccessible portions of occipital scalp has been spared.
patches, the hair is short and broken off at varying lengths (Fig. lOA). In more severe cases, the patient compulsively breaks off the hair on the entire scalp except that on the most inaccessible portions of the occipital scalp; this produces a characteristic clinical picture (Fig. lOB).
In many children, the condition may merely be a tic analogous to nail-biting and may require no special attention. In others, bringing the habit to the child's attention and reassuring him is enough to stop the tic. However, the need of each child for psychiatric evaluation should be individually considered.
TRACTION AND TRAUMATIC ALOPECIA Hair styles may cause traction alopecia if excessive tension is applied to the hair for long periods. Tight ponytails and braids (Fig. 11) and the revived custom of "corn-rowing" are examples of such hair styles. Releasing the tension on the hair reverses the problem in most cases, but occasionally, when traction has been prolonged, alopecia may be permanent. Children may pull out hanks of hair from each other during play. In this situation, it is helpful to know that regrowth may be delayed for several months, because, when growing follicles are forcibly avulsed, they take about three months to return to the growing phase. Friction can cause breakage of the hair shaft, and infants often have localized areas of hair loss from the friction of rubbing the scalp on the bed.
DISORDERS OF THE HAIR IN CHILDREN
317
Figure 11. Traction alopecia and folliculitis resulting from prolonged traction of tight braids.
INFECTIONS The key features of fungal infections of the scalp are patchy, partial hair loss, with broken hairs and scaling (Fig. 12). Without a high index of suspicion, tinea capitis is often misdiagnosed as trichotillomania or alopecia areata. The clinical appearance of tinea capitis varies with the species of dermatophyte involved and with the degree of host resistance. Some patients show only a few patchy, gray areas with broken hairs and mild scaling, whereas others have an acute, severe inflammatory process that affects large areas of the scalp. Diagnosis is made by examination of the hair with a Wood's light, by microscopic examination of broken hairs in a potassium hydroxide mount, and by culture of the broken hairs. Treatment with griseofulvin
Figure 12. Tinea capitis, showing characteristic gray patch with broken hairs and scaling.
318
VERA
H.
PRICE
"
is very satisfactory. Depending on the dermatophyte involved, human and animal contacts must also be found and treated. Bacterial infections such as impetigo, furuncles, and ecthyma can involve the scalp. If the process is superficial, then any hair loss is temporary. If, however, the follicle is destroyed by the inflammatory process, a permanent scarring alopecia is produced. Viral infections such as herpex simplex, zoster, varicella, and the common wart may also affect the scalp; here again, the hair loss may be temporary or permanent, depending on whether the hair follicle is destroyed.
TOXIC ALOPECIA Cancer therapeutic drugs may cause extensive scalp hair loss. These agents cause a temporary arrest of mitotic activity in the matrix region of growing hairs; this results in constriction of the hair shaft and subsequent hair breakage. The hair loss begins about one to three weeks after systemic administration of one of these drugs is started, and 80 to 90 per cent of the hairs are affected. All categories of cancer therapeutic agents produce this hair loss, including the antimetabolites (such as methotrexate, 6-mercaptopurine, or 5-fluorouracil), the alkylating agents (such as nitrogen mustard, chlorambucil, cyclophosphamide, or thiotepa), and cell poisons (such as antinomycin D, colchicine, or vinblastine). Treatment is unnecessary because the hair recovers promptly after the pharmacologic activity of the drug ceases, even after repeated therapeutic courses. Nonspecific toxic alopecia may be caused by heavy metals such as lead and arsenic, and by many drugs, including trimethadione, thallium, heparin, coumarin, triparanol, thiourea, carbamazepine, and lithium carbonate. In most cases, the hair regrows when the offending drug is stopped.
NUTRITIONAL, METABOLIC HAIR LOSS In general, a wide variation of dietary customs is compatible with normal hair growth, and nutritional deprivation must be severe before hair growth is affected. Because hair keratin is composed almost entirely of fibrous proteins, an adequate dietary protein intake is required for normal hair growth. In situations when dietary protein plus mobilized body protein are insufficient to meet body requirements, the low priority of hair growth for available protein results in increased numbers of hairs entering the telogen phase as a protein-sparing mechanism. 2 As a result, there is a marked increase in hair shedding from the increased numbers of telogen follicles. Such a situation occurs during crash dieting if protein intake is inadequate. 2 • 16 In the more extreme examples of kwashiorkor and marasmus, hair is not only shed but also changed morphologically; in fact, it is used as a public health tool in the assessment of protein-calorie malnutrition in the field. 3 The severe malnutrition that occurs in celiac disease similarly affects the hair.
DISORDERS OF THE HAIR IN CHILDREN
319
Vitamin A can cause hair loss if taken in either excessive or inadequate amounts. In general, the daily ingestion of surplus vitamins does not produce healthier, stronger hair, as is frequently claimed in advertisements. In acrodermatitis enteropathica, alopecia accompanies the severe diarrhea and dermatitis. Following the discovery that this autosomal recessive condition is due to zinc deficiency, the administration of zinc orally has reversed all the signs and symptoms, including the hair loss.24 HORMONAL INFLUENCES ON HAIR GROWTH Hormones modify both the hair cycle and the caliber of the hair that is produced. The duration of the growing and resting phase of the cycle is particularly influenced by excess or deficiency of glucocorticoids or thyroid hormone. as These hormones may either accelerate or delay the initiation of the anagen phase, and hence may determine the number of hairs in anagen and telogen. In both hypothyroidism and hyperthyroidism, the ratio of telogen to anagen hairs is increased. Disturbances of the hair cycle are usually reversed when the hormonal influence is corrected. Vellus hair may become terminal hair, and terminal hair may become vellus, as a result of hormonal stimulation or by genetically determined responses of the follicular target organs. Androgens and growth hormone are usually the hormones responsible for such changes in hair caliber.as In virilizing syndromes, vellus hair changes into coarse terminal hair in certain body regions which are determined by age and by the genetic constitution. In androgenetic alopecia (common baldness), terminal hair gradually becomes miniaturized into vellus hair in certain genetically predisposed follicles on the scalp under the influence of normal levels of circulating androgen. 29 Changes in hair caliber are usually not completely reversed, in some cases not at all, by removal of the hormonal stimulus. REFERENCES 1. Allan, J. D., Cusworth, D. c., Dent, C. E., et al.: A disease, probably hereditary, characterised by severe mental deficiency and a constant gross abnormali-ty of aminoacid metabolism. Lancet, 1 :182, 1958. 2. Blackburn, G. L., Bristrian, B. R., and Hoag, C.: Hair loss with rapid weight loss. J.A.M.A., 236:252,1976. 3. Bradfield, R. B., and Bailey, M. A.: Hair root response to protein undernutrition. In Montagna, W., and Dobson, R. L. (eds.): Advances in Biology of Skin. Oxford, Pergamon Press, 1969, p. 109. 4. Brenton, D. P., Cusworth, D. C., Hartley, S., et al.: Argininosuccinicaciduria: Clinical, metabolic and dietary study. J. Ment. Defic. Res., 18:1,1974. 5. Bucknall, W. E., Haslam, R. H. A., and Holtzman, N. A.: Kinky hair syndrome: Response to copper therapy. Pediatrics, 52:653, 1973. 6. Chernosky, M. E., and Owens, D. W.: Trichorrhexis nodosa: Clinical and investigative studies. Arch. Dermatol., 94:577, 1966. . 7. Comaish, S.: Metabolic disorders and hair growth. Br. J. DermatoL, 84:83,1971. 8. Crounse, R. G.: Trichorrhexis nodosa and amino acid metabolism. Arch. DermatoL, 86:391, 1962.
320
VERA
H.
PRICE
9. Cunliffe. W. J., Hall, R, Newell, D. J., et al.: Vitiligo, thyroid disease and autoimmunity. Br. J. Dermatol., 80:135,1968. 10. Cunliffe, W. J., Hall, R, Stevenson, C. J., et al.: Alopecia areata, thyroid disease and autoimmunity. Br. J. Dermatol., 81 :877, 1969. 11. Danks, D. M.: Steely hair, mottled mice and copper metabolism. New Engl. J. Med., 293:1147,1975. 12. Danks, D. M., Campbell, P. E., Stevens, B. J., et al.: Menkes' kinky hair syndrome: An inherited defect in copper absorption with widespread effects. Pediatrics, 50: 188, 1972. 13. Danks, D. M., Cartwright, E., and Stevens, B. J.: Menkes' steely-hair (kinky-hair) disease. Lancet, 1 :891, 1973. 14. Efron, M. L., and Hoefnagel, D.: Argininosuccinic acid in monilethrix. Lancet, 1 :321, 1966. 15. Flesch, P.: Hair growth. In Rothman, S. (ed.): Physiology and Biochemistry of the Skin. Chicago, University of Chicago Press, 1954, p. 601. 16. Goette, D. K., and Odom, R. B.: Alopecia in crash dieters. J.A.M.A., 235:2622,1976. 17. Grover, W. D., and Scrutton, M. C.: Copper infusion therapy in trichopoliodystrophy. J. Pediat., 86:216,1975. 18. Hersle, K.: Netherton's' disease and ichthyosis linearis circumflexa: Report of a case and review of the literature. Acta Derm. Venereol. (Stockh.), 52:298,1972. 19. Hutchinson, P. E., Cairns, R J., and Wells, R S.: Woolly hair; Clinical and general aspects. Trans. St. John's Hosp. Derm. Soc. (Lond.), 60:160,1974. 20. Kern, F., Hoffman, W. H., Hambrick, G. W., Jr., et. al.: Alopecia areata: Immunologic studies and treatment with prednisone. Arch. Dermatol, 107:407,1973. 21. Levin, B., Mackay, H. M. M., and Oberholzer, V. G.: Argininosuccinic aciduria: An inborn error of amino acid metabolism. Arch. Dis. Child, 36:622, 1961. 22. Mackee, G. M., and Rosen, I.: Monilethrix: A clinical and histological study, with a report of six cases and a review of the literature. J. Cutan. Dis., 34:444, 1916. 23. Mevorah, B., Frenk, E., and Brooke, E. M.: Ichthyosis linearis circumflexa Comel: A clinico-statistical approach to its relationship with Netherton's syndrome. Dermatologica, 149:201, 1974. 24. Neldner, K. H., and Hambidge, K. M.: Zinc therapy of acrodermatitis enteropathica. New Engl. J. Med., 292:879,1975. 25. Papa, C. M., Mills, O. H., Jr., and Hanshaw, W.: Seasonal trichorrhexis nodosa: Role of cumulative damage in frayed hair. Arch. Dermatol., 106:888, 1972. 26. Penders, A. J. M.: Alopecia areata and atopy. Dermatologica, 136:395,1968. 27. Porter, P. S., and Lobitz, W. C., Jr.: Human hair: A genetic marker. Br. J. Dermatol., 83:225.1970. 28. Price, V. H.: Office diagnosis of structural hair anomalies. Cutis, 15:231,1975. 29. Price, V. H.: Testosterone metabolism in the skin: A review of its function in androgenetic alopecia, acne vulgaris, and idiopathic hirsutism including recent studies with antiandrogens. Arch. Dermatol., 111: 1496, 1975. 30. Price, V. H., Thomas, R S., and Jones, F. T.: Pili annulati: Optical and electron microscopic studies. Arch. Dermatol., 98:640, 1968. 31. Price, V. H., Thomas, R. S., and Jones, F. T.: Pseudopili annulati: An unusual variant of normal hair. Arch. Dermatol., 102:354, 1970. 32. Robinson, G. C., and Johnston, M. M.: Pili torti and sensory neural hearing loss. J. Pediat., 70:621, 1967. 33. Robinson, V. N. E.: A study of damaged hair. J. Soc. Cosmet. Chem., 27:155,1976. 34. Ronchese, F.: Twisted hairs (pili torti). Arch. Derm. Syph., 26:98,1932. 35. Rook, A.: Endocrine influences on hair growth. Br. Med. J., 1 :609,1965. 36. Sanderson, K. V., and Hall-Smith, P.: Tonsure trichotillomania. Br. J. Dermatol., 82:343, 1970. 37. Solomon, L. M., and Esterly, W. B.: Neonatal Dermatology. Philadelphia, W. B. Saunders Co., 1973, p. 191. 38. Stevanovic, D. V.: Multiple defects of the hair shaft in Netherton's disease: Association with ichthyosis linearis circumflexa. Br. J. Dermatol, 81 :851, 1969. 39. Summerly, R, and Donaldson, E. M.: Monilethrix: A family study. Br. J. Dermatol., 74:387, 1962. 40. Tomlinson, S., and Westall, R G.: Argininosuccinic aciduria: Argininosuccinase and arginase in human blood cells. Clin. Sci., 26:261, 1964. 41. Wilkinson, R D., Curtis, G. H., and Hawk, W. A.: Netherton's disease: Trichorrhexis invaginata (bamboo hair). congenital ichthyosiform erythroderma and the atopic diathesis. A histopathologic study. Arch. Dermatol., 89:46, 1964. Department of Dermatology Kaiser-Permanente Medical Center 2200 O'Farrell Street San Francisco, California 94115