PEDIATRIC SURGERY FOR THE PRIMARY
0031-3955/98 $8.00
CARE PEDIATRICIAN, PART II
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PEDIATRIC DERMATOLOGIC SURGERY FOR THE PRIMARY CARE PEDIATRICIAN Debra Babich, MD, and Jill S. Crollick, EdM, MD
Surgical manipulation of the skin, mucous membranes, and nails is a large part of the practice of dermatology. Biopsies are performed to confirm clinical impressions or to make diagnoses that are clinically unclear. Lesions can be treated with cryosurgery, chemosurgery, laser surgery, and cold steel surgery. Cosmetic procedures are performed routinely by many dermatologists, dermatologic surgeons, general surgeons, plastic surgeons, otolaryngologists, ophthalmologists, and cosmetic surgeons. Similar techniques can be applied to the pediatric patient for correction of birth anomalies of the skin. All dermatologists are trained to identify and treat skin lesions in both pediatric and adult patients. Some prefer not to perform biopsies or other surgical procedures on small children, but most treat all age groups. Today, however, many dermatologists treat only children. The Society for Pediatric Dermatology was established in 1975 and meets twice yearly to discuss unusual cases, management problems, and topics that are the cutting edge in pediatric dermatology. Issues in pediatric dermatologic surgery are commonly addressed, including tissue expansion, removal of congenital lesions, and laser treatment of hemangiomas and vascular malformations. Physicians involved in the primary care of infants and children should understand differential diagnosis, natural history, and treatment options for dermatologic lesions. This understanding helps to ensure accurate diagnosis, referral (when necessary), and optimal treatment. In the first section of this article, basic office dermatologic surgery is addressed, including anesthesia choices, biopsy decision making and techniques, cryosurgery, and chemosurgery. The second section covers the decision-making process for choosing surgery in several dermatologic conditions in children, including congenital melanocytic nevi, aplasia cutis, nevus sebaceous, and port-wine stains. ~
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From the Department of Dermatology, State University of New York at Buffalo, Buffalo, New York PEDIATRIC CLINICS OF NORTH AMERICA VOLUME 45 * NUMBER 6 DECEMBER 1998
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BASIC OFFICE DERMATOLOGIC SURGERY Anesthesia
Local anesthesia is most commonly used for office skin procedures, but there are indications for sedation or general anesthesia. This section addresses local anesthesia, both injectable and topical. Most injectable, local anesthetics can be classified into two groups: (1) ester and (2) amide. In general, the amide group has been shown to have a lower incidence of allergic reactions compared with the ester group. Today, the most commonly used anesthetic is the amide lidocaine. Advantages of lidocaine include rapid onset of action and moderate duration of activity. Lidocaine rarely causes allergic reactions, but toxicity may result from a dose that is too large, administration that is too rapid, or slow elimination or biotransformati~n.~~ Lidocaine is available in concentrations of 0.5%, 1.0%, and 2.0%, with or without epinephrine. Epinephrine is a potent vasoconstrictor and is a valuable adjunct to local anesthesia. It slows the absorption of the anesthetic, thereby reducing the incidence of toxicity, and prolongs the action of the anesthetic, increasing the efficacy of the drug. Without epinephrine, lidocaine can be expected to last 30 to 120 minutes; with epinephrine, 60 to 400 minutes. Epinephrine reduces bleeding at the operative site. Because of its vasoconstrictive power, anesthetic with epinephrine should never be used on the penis, fingers, or toes and should be used with caution on the nose and ears.24 When a procedure needs to be performed, small children generally are upset about being restrained. For older children, the anticipation of pain causes fear and anxiety. Injection of a local anesthetic is, for a very short time, painful. Both the needle stick and the infiltration of the anesthetic hurts. Techniques used to decrease the pain of needle insertion include distraction by pinching the skin at a distant site before insertion of the needle, the use of a 30-gauge needle, icing the area for 1 or 2 minutes before the procedure, or first using a topical anesthetic. The discomfort associated with infiltration of the local anesthetic is caused by increased tissue pressure and the acidity of the anesthetic. Slow administration minimizes the pain associated with this increase in pressure, and the addition of sodium bicarbonate (1 mL 8.4% sodium bicarbonate in 10 mL lidocaine) raises the pH of the solution, also helping to reduce pain. Because sodium bicarbonate inactivates epinephrine, buffered anesthetic with epinephrine should be used immediately.l4.24 In children, a topical anesthetic is preferable over an injectable anesthetic in many cases. The ideal topical agent provides anesthesia of adequate depth, has a short onset of action, is painless, works on intact skin, and has no systemic side effects. A topical agent close to this ideal is a eutectic mixture of local anesthetics (EMLA), which is a eutectic mixture of lidocaine and prilocaine. Most pure anesthetics are solid at room temperature and must be converted to a liquid so that they can be used in topical formulations. A eutectic mixture melts at a lower temperature than any of its individual ingredients so that higher concentrations of the active ingredients are available for infiltration through the skix1.2~ EMLA must be applied under an occlusive dressing (Tegaderm, 3M, St. Paul, MN) at least 1 hour before a procedure. Longer application times increase effectiveness and depth of anesthesia. When applied to open, denuded areas or mucous membranes, only 5 to 30 minutes are needed. Studies regarding depth of activity state that after a 60-minute application, the maximum analgesia is 3.0 mm and after 120 minutes, 5.0 mm.24Blanching at the treatment site can be
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considered a disadvantage because it can interfere with treatment of vascular lesions or biopsy of erythematous macules by making the affected areas less visible. Caution should be used when applying EMLA to large areas because of the increased concentrations of lidocaine and prilocaine and the risk for toxicity. Furthermore, EMLA can cause methemoglobinemia.ll,41 Dosage recommendations for the size of infants or children should be carefully checked before use. Amethocaine, a topical anesthetic recently proven effective, is not yet available in the United States. It penetrates the stratum corneum readily; is more potent because of a high affinity for nerve tissue; and binds avidly, creating a longer-lasting effect. These characteristics explain an onset of action in 40 to 45 minutes and a duration of up to 3 hours. EMLA takes longer to work and lasts for a shorter period of time. No toxicity has yet been reported for amethocaine, which is understandable because it is cleared by esterases in the skin and bloodstream. However, because the active ingredient is an ester, a theoretic increase exists in risk for allergic reaction, which has not been reported to date.5,21.24 Iontophoresis, a method of delivering medication through the use of an 29, 47 electric current, is another method of providing local anesthesia painlessly.10* Iontophoresis takes advantage of lidocaine and epinephrine existing as positively charged ions in solution. When the iontophoretic device is in the positive mode, the positively charged electrode repels the positively charged drug, forcing it through the skin. Anesthesia occurs in 10 to 30 minutes. Although generally regarded as painless, some patients report stinging or burning. The bulkiness of the machine is a disadvantage, and electrochemical burns may result from the A new iontophoretic device is available application of DC current to the that uses AC current that does not result in cutaneous burns8
Skin Biopsy
Skin biopsy is a skill that can be mastered by any physician.z3,46 How to perform the biopsy is the smallest fraction of the knowledge required to use this diagnostic technique, however. Several factors must be considered before a dermatologic biopsy is performed, including: Which technique should be used, and why? Is lesion in the midline? How large of a sample is needed for accurate diagnosis? Should new or old lesions be sampled? How will the biopsy site be closed? What special instruments are needed for specific sites? What special stains are needed? Is immunofluorescence needed? What special transport media or arrangements are needed? Is the pathologist sufficiently trained in dermatopathology? Imaging before biopsy should be considered for midline cystic lesions that may have an underlying connection to other structures, such as a thyroglossal duct cyst. Adequate tissue and the cosmetic end result are important considerations in deciding the size of the biopsy. For example, biopsies of hair-follicle disorders and pigmented lesions may need to be larger than 2 mm or 3 mm. When lesions are in different stages of development, biopsy of a new versus mature lesion depends on the clinical differential diagnosis. Biopsy sites in
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intertriginous areas should be closed with silk or absorbable suture material or left to heal by secondary intention. Special histologic staining is sometimes required; for example, periodic acid-Schiff is needed for identification of fungi, and immunofluorescent staining is used for detecting antibodies in bullous disorders. Tissue samples requiring special staining must also be transported in specific solutions, not formalin used for routine biopsy. $kin biopsies can be performed using several techniques, including punch biopsy, tangential biopsy, incisional biopsy, excisional biopsy, and curettage. The choice of which technique to use depends on the differential diagnosis of the lesion and what tissue layer (i.e., epidermis, dermis, or subcutaneous fat) needs to be biopsied. Tangential or shave biopsies, which mostly sample epidermal cells with some papillary dermal cells, can miss lesions extending deeper into the dermis. They can be accomplished with a no. 15 blade, a flexed straight blade, or scissors. Hemostasis is often achieved with topical aluminum chloride or ferric subsulfate (Monsels solution), electrocautery, or pressure. The wound heals by secondary intention. Similarly, a curette can be used to scrape off tissue. Curettage can be used to remove molluscum contagiosum lesions. Curettage with electrodessication is a treatment for basal cell cancers that, in the pediatric population, can be seen in the basal cell nevus syndrome. Tangential removal can also be used for cosmetic removal of moles that are not clinically suspicious; however, melanocytes can remain, and the lesion can regrow. If the same area is biopsied in the future,-the tissue can show melanocytes in the previous scar and can erroneously be identified as a melanoma. Similarly, measurement of the depth of a melanoma (Breslow level) may be impossible when the tissue is removed by the tangential technique. The Breslow level is a significant prognostic tool in deciding treatment options. Although melanoma is extremely rare in pediatric patients who have no risk factors, lesions suspicious for melanoma should be biopsied with a technique (i.e., incisional, excisional, or punch biopsy) that allows measurement of the level. Excisional biopsy with a scalpel or cutting laser is used when the complete lesion is needed for examination or when the lesion is sufficiently small to be removed in its entirety. Incisional biopsy, removal of only a portion of the lesion, is used when a larger lesion is sampled or when the lesion is in a location not amenable to excisional biopsy for cosmetic or functional reasons. Incisional biopsy is also chosen when a specific pathologic architecture needs to be demonstrated. For example, in the special case of diagnosing panniculitis, inflammation of the subcutaneous tissue, an incisional biopsy is preferred. When incisional biopsy is not possible, the punch biopsy technique can be modified to obtain adequate tissue for diagnosis? A punch biopsy is the most commonly used biopsy technique and uses a preformed circular blade on a handle. Punches come in varying sizes of 2 mm and larger. Care must be used in handling tissue obtained with this technique because punch biopsy tissue is prone to “crush artifact“ when the tissue is handled by forceps while the base is cut. Punch biopsy holes can be left to heal by secondary intention or closed with sutures. New tissue adhesives that may prove useful for closure are being developed.= Punch biopsy wounds smaller than 5 nun can be easily closed primarily without “dog ears.” Larger punch biopsies should be made with tension on the skin, perpendicular to the axis of anticipated closure, such that the wound created will be an oval and easy to close. Biopsy of the nail bed, nail matrix, or nail plate for diagnosis of onychomycosis, tumor, or melanonychia, by incision or punch, requires a complete
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understanding of the anatomy and pathology of the nail unit. Choice of the appropriate site is crucial and is particularly important in biopsying melanonychia (longitudinal pigmentation of the nail bed) to rule out melanoma. In this case, biopsy of the nail matrix can result in permanent splitting of the Biopsy of the lip at or within the vermillion border, of the oral mucosal surface, or of the genital mucosa also requires knowledge of the anatomy and expected pathology and can require a special technique, instruments, and method of closure to preserve cosmesis. Cryosurgery
Cryosurgery, the destruction of tissue by the application of extreme cold, most commonly uses liquid nitrogen, which has a boiling point of -196°C. Although cryosurgery can be used for treatment of some malignant skin lesions, this application is not addressed because of the rarity of pediatric indications. In children, liquid nitrogen is usually used to treat common warts, genital and perianal warts, molluscum contagiosum, and pyogenic granulomas or to soften keloids before injection of corticosteroids. This treatment causes a freezing and then a burning sensation when the liquid nitrogen is applied and while the frozen tissue thaws. Because of fears and limited cooperation, it is often not a good choice for children younger than 3 years of age. When children can understand the treatment and cooperate with the procedure (often 6 years of age or older), cryosurgery becomes a useful addition to treatment ~ 1 a n s . I ~ With cryosurgery, correct application is important to achieve the desired effect. Maximum tissue destruction is achieved through quick freezing and slow thawing. Liquid nitrogen can be applied by cotton-tipped applicator or a spray gun. The cotton-tipped applicator can also be used to apply pressure that increases the depth of the freeze. Thin epidermal lesions usually respond to a single freeze-thaw cycle. Thicker lesions might require a longer freeze and repeated cycles. Although underfreezing is a common beginner's error, overfreezing can cause significant pain, hemorrhage, and necrosis, with resulting scarring and dy~pigmentation.'~ Post-therapy effects occur within minutes with erythema and edema. Within 24 to 48 hours, vesicles or bullae may form, which resolve in several days. The abnormal cells peel off with the roof of the blister. Risks and benefits of cryosurgery should be understood and accepted by the patient or parent before performing the procedure. Complications include scarring, hyperpigmentation or hypopigmentation, and nerve damage, especially when cryosurgery is performed on thin skin where the nerves are close to the surface, such as on the lateral aspects of the fingers.%Because melanocytes are very sensitive to cold injury, care should be taken when using cryotherapy in darkly pigmented patients.I4 After treatment with liquid nitrogen, common warts and pyogenic granulomas can heal with central clearing and a new ring of lesions at the treatment site. This result can occur without advance warning, and the possibility of occurrence should be part of the consent process. Chemosurgery
Topically applied chemicals have proven to be extremely effective in removal of lesions such as common and plantar warts, genital and perianal warts, and molluscum contagiosum. Chemical softening of the nail plate for removal can be useful in the treatment of onychomycosis to decrease the fungal presence
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and to allow topical treatment. Effective oral treatment of onychomycosis has decreased the need for this therapeutic aid, but it is still useful in some situations. Chemosurgery is a suitable option for young children and infants because application is usually quick and painless. Many preparations are available for home use, both by prescription and over-the-counter. Cantharidin, an extract of the blistering beetle Cunthuris vesicutoriu, is a potent blistering agent that is applied painlessly. The blister dries and peels off, taking with it the epidermal lesion. This agent should not be applied to the genitalia or face because of the potential for severe blistering, and it should not be dispensed to the patient for use at home. The physician applies the liquid with the wooden end of a cotton swab, a toothpick, or a glass rod, and the solution is allowed to air dry. Tape is then applied for occlusion and for protection of normal skin. After at least 4 hours, the tape is removed and cantharidin is washed off. The patient should be aware that, in the case of warts, a ring of satellite warts can occur at the periphery of the treated area. Cantharidin can also be combined with podophyllin or salicylic acid to create an even more potent blistering agent.19, At present, cantharidin is commercially available in Canada already prepared in a collodion base; however, in the United States, only the components of this blistering agent preparation are available and must be mixed by the physician. Podophyllin, an extract from the dried roots of either Podophyllum peltaturn or Podophyllum emodi, is used for the treatment of genital or perianal warts. It is effective only on mucosal surfaces. It is available in different concentrations and in different vehicles (i.e., benzoin, alcohol, and collodiofl). Lesions are treated sparingly with a wooden or glass applicator and allowed to air dry. Podophyllin is an antimitotic drug that works by arresting dividing cells in metaphase and preventing cell division. Therefore, biopsy of areas previously treated with podophyllin must always be so labeled so that the pathologist will not erroneously read a malignancy with abnormal mitoses. Absorption is possible when applied to large mucosal surfaces, so the volume used should be limited. Adverse hematologic effects include leukopenia and thrombocytopenia. Podofilox, a purified form of the podophyllum resin, is available by prescription. The patient treats the genital warts at home twice daily, 3 days per week, for 4 week^.'^,^^
Salicylic acid is a keratolytic agent that destroys tissue when used in concentrations of more than 6%. It produces desquamation of the stratum comeum without affecting the other layers of the epidermis. It is available for over-thecounter use in liquids, patches, and plasters for common and plantar warts. Treatment should be applied nightly, with the dead skin scraped off each moming. Prolonged use over large areas, particularly in patients with renal or hepatic impairment, may lead to salicyli~m.~~ Topical salicylic acid is an excellent, mild treatment; however, because nightly application over weeks and even months is sometimes required, it is human nature to become frustrated and decrease the frequency of treatment, resulting in treatment failure. Topical chloroacetic acid produces necrosis of the epidermis, leading to blister formation. It is available in 80% monochloracetic and 50% to 80% saturated bichloracetic and trichloracetic acids. The latter are not as potent as monochloracetic acid but are still effective in treating warts. Treatment requires skill to limit the area of skin exposed. Repeat applications in biweekly intervals are often needed." 5-Fluorouracil is a chemotherapeutic agent that is available in both cream and solution in 1% and 5% concentrations. It is a pyrimidine analog that suppresses DNA synthesis by inhibiting thymidylic synthetase. It has been used
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effectively for eradication of flat warts, periungual warts, and genital warts. It is also used to treat precancerous lesions caused by the sun, actinic keratosis (AK), or to treat superficial squamous cell cancer (Bowen's disease). The pediatric application of this agent is for treatment of AKs found in patients with xeroderma pigmentosum (Fig. 1).This genodermatosis is actually a group of disorders caused by abnormal repair mechanisms of DNA damaged when exposed to sunlight. With a deficiency of this enzyme, exposure to sunlight results in severe sunburnlike reactions. As early as 6 years of age, different types of benign and malignant skin tumors develop. Although most tumors require excision, AKs can be treated with 5-fluorouracil or cryotherapyZ7The advantage of topical 5-fluorouracil is that it treats AKs that are not clinically apparent and the ones that are. Activity of the 5-fluorouracil can be enhanced by occlusion or addition of salicylic acid or t r e t i n ~ i n . ~ ~ Tretinoin, in cream or gel vehicles, can be used on molluscum contagiosum or flat warts for its desquamative effect. Lesions are treated two or three times daily to the point of irritation and subsequent peeling. Its well-known use for acne is based on normalizing the progression of basal cell to mature keratinocytes and promoting the normal shedding of these cells (irregular cell turnover and abnormal shedding produces the initial lesion in acne, the keratin plug in the hair follicle, the microcomedo). Although treatment of acne with tretinoin does not require desquamation, it is this common side effect that removes superficial epidermal lesions? Topical antifungal preparations do not penetrate the nail plate well and, therefore, are less effective than oral antifungals for the treatment of onychornyc0sis.1~Urea is a proteolytic agent that can remove nails when used in concentrations exceeding 40%. Typically, urea in a lanolin base is applied to affected nails and occluded for several days. The soft keratin can then be curetted off, and topical antifungals With the new, relatively safe, and effective oral antifungals, itraconazole and terbinafine, this surgical approach should decrease in usefulness. USE OF SURGERY IN SELECTED DERMATOLOGIC CONDITIONS IN CHILDREN
Nevus Sebaceous
Nevus sebaceous is a cutaneous hamartoma on the head and neck first described by Jadassohn in 1895.28,M It is most commonly seen at birth but occasionally becomes visible later in childhood. It is also referred to as an organoid neuus because it affects all components of the skin except the eccrine Lesions are usually solitary; well circumscribed; devoid of hair; and oval, round, or linear in shape. Initially, the affected areas are yellow to yellowbrown to orange or pink, and appear as flat, velvety plaques ranging in size from a few millimeters to several centimeters (Fig. 2). After puberty, the surface can become raised, thickened, and papillomat~us.~~, Histologically, the appearance also varies with age. Initially there is acanthosis, abortive hair follicles, sebaceous hyperplasia, and apocrine sweat glands. After the onset of puberty, a proliferation of sebaceous and apocrine glands and increased epidermal hyperplasia occur, explaining the clinical thickening of the lesion.% Very large plaques of nevus sebaceous present in the lines of Blaschko (embryonic lines of cutaneous development) on the face and scalp, when associated with other abnormalities, such as ophthalmic abnormalities, mental retarda-
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Figure 1. Facial actinic keratoses in an 8-year-old boy with xeroderma pigmentosum. Figure 2. Nevus sebaceous. Figure 3. Aplasia cutis congenita, healed. Flgure 4. Giant congenital nevomelanocytic nevi (CNN) in bathing trunk distribution with satellites. Figure 5. CNN overlying midline with increased risk of leptomeningeal melanocytosis and spinal defects. Flgure 6. CNN presenting in area where removal could be cosmetically sensitive but longterm observation would be possible.
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Figure 3.
Figure 5.
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tion, skeletal abnormalities, and seizure disorders, are called the nevus sebaceous syndrome.l7 Samples from the scalp and face in systematized epidermal nevus syndrome can be read histologically as nevus sebaceous.27 It is often recommended that nevus sebaceous be surgically removed because benign and malignant epidermal and adnexal neoplasms can arise in these lesions after puberty.% The most common benign neoplasm is syringocystadenoma papilliferum, occurring in 8% to 19% of cases. The most common malignant neoplasm is basal cell cancer, with a reported incidence of 6.5% to 50.0%." Other less common tumors, arising from different skin components found in hamartomas, include trichoblastoma, keratoacanthoma, leiomyoma, piloleiomyoma, hidradenoma, and apocrine cy~tadenoma.'~ Although rare, aggressive neoplasms with metastases including squamous cell carcinoma, apocrine carcinoma, and malignant eccrine poroma have been reported. These reports involve individuals 45 to 77 years of age, with a median age of 64.5 years.&Malignant degeneration is usually accompanied by the appearance of a discrete nodule, with or without superficial ulceration. Because the onset of tumor growth can be insidious, making the diagnosis of carcinoma arising in a nevus sebaceous can be difficult without biopsy. Therefore, prophylactic excision at puberty is often recommended. This recommendation usually applies to the more common individual lesions, rather than the syndromic, because the individual lesions are usually more amenable to removal. Deep surgical excision, rather than tangential excision, is recommended to prevent local re~urrences.'~ Those with extensive lesions of the nevus sebaceous syndrome or epidermal nevus syndrome should have routine skin surveillance by a dermatologist to screen for tumor development. A decision must be made about when to do the surgery. General anesthesia should be avoided whenever possible. It is'commonly recommended that removal be at puberty, when the patient can cooperate with biopsy under local anesthesia.&Parents can be reminded that if general anesthesia is required for another reason during childhood, excision of the nevus sebaceous could be performed at the same time. A routine elliptical excision is usually all that is needed; however, closure of larger defects in the scalp created by the removal of the lesion can necessitate staged excision, tissue expansion, or other plastic surgical approaches.46 Aplasia Cutis Congenita
Aplasia cutis congenita is a congenital defect of the skin characterized by focal absence of epidermis, dermis, and occasionally subcutaneous tissue. The condition is present at birth and may occur anywhere on the body, although the scalp is the most common location. Although To0/" of patients have a single ICsion, 20% have two lesions, and 8% have three or more. The defect is most commonly located along the midline, but in 30% of cases it is adjacent to the Parietal and posteriqr auricular lesions are found in 20% of patients. Lesions are usually small, but large variants occur. Large skin defects are usually associated with bony defects, with an estimated 20% t o 30% involving the calvaria and dura mater.6-22 At birth, the presentation varies from a superficial ulceration with an erythematous, weeping, or granulomatous base to a bullous lesion with a thin membranous covering." l6 Lesions may be round, oval, triangular, or stellate and generally have regular or sometimes inflamed borders.6*22 The area heals as a hairless scar, so the older child may present with a smooth area of alopecia.16
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The degree of dermal and subcutaneous involvement can vary, so the scar may be of thin or normal thickness (Fig. 3). The cause of aplasia cutis is unknown but thought to be multifactorial. Recently support for an association with neural tube defects was found in patients who had membranous aplasia cutis with a hair collar sign (a ring of different or thicker hair).6Although aplasia cutis is usually an isolated event, it can be seen in as many as 20% of cases with associated an0malies.4~Some of the more common of these anomalies include limb defects, bone defects, epidermolysis bullosa, and heart lesions. Although the prognosis of isolated aplasia cutis is generally favorable, with spontaneous healing during the first few weeks or months of life, aplasia cutis presenting as large scalp lesions, exposing the dura mater and sagittal sinus, require urgent treatment soon after birth?, 22 Dermatologic surgery is possible for removal of the scars of aplasia cutis to achieve a more consistent hair coverage if necessary. Similar to removal of nevus sebaceous, the timing of the repair should address the risk for general anesthesia and the need for tissue movement to cover the defect. Congenital Nevomelanocytic Nevus
Congenital nevomelanocytic nevi (CNN) are pigmented lesions present at birth and grow in proportion to body growth. Rarely, lesions may become visible between 1 month and 2 years of age. These tardive CNNs may represent nevus cells, clinically imperceptible but histologically present at birth, that develop surface pigment in time.31A nevomelanocytic nevus that appears after birth is an acquired nevomelanocytic nevus, or the “common mole.” The average person can have 40 moles by the age of 40 years. The distinction must be made because CNNs have an increased risk for degeneration into malignant melanoma. The problem is determining which CNNs have the greatest risk. Traditionally, CNNs have been separated into two or three classes (i.e., small, medium, and large or giant), even though no uniform criteria for this classification exist. Some regard a CNN as small if excision is easy, without resultant deformity and without the need for flaps and grafts. This type of classification can be greatly affected by the anatomic location because a 3-cm lesion may be classified as small if it is located on the trunk but large if it is on the face or genitalia. Definitions based on size are also variable. Some authors regard giant nevi as being the size of the palm if they are located on the face and twice that if on the trunk, whereas others believe that giant CNNs comprise at least 30%,of the body surface area.%The most recent classification is based on the measurement of the largest diameter of the lesion. Thus measured, small CNNs are defined as being less than 1.5 cm; medium, 1.5 cm to 19.9 cm; and large or giant, more than 20 cm.20 The incidence of congenital nevi is approximately 1%,with most lesions being singular and small (< 1.5 cm). It has been estimated that 1 in 6900 persons will have lesions measuring more than 4.1 cm and that 1 in 20,000 will have lesions measuring more than 9.9 cm. Congenital nevi with a garment distribution occur in 1 of 500,000 newboms.17,31, 34 Small to medium congenital nevi begin as round or oval, tan macules or papules, often with darker pigmentation mottled throughout the lesion. The borders are smooth and sharply defined but irregular. In time, they can become elevated and develop a verrucous surface. Coarse, dark hairs can develop from these lesion^.'^,^^ In contrast, caf6-au-lait spots are macular and do not become
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elevated or develop a verrucous surface. At birth, it is not always possible to distinguish a congenital nevus from a caf6-au-lait spot. Giant congenital nevi can be found in dermatomal distribution. They are also known as garment nevi (bathing trunk or coat sleeve) or giant hairy nevi (Fig. 4). Like small to medium lesions, they tend to be unevenly pigmented, with irregular but well-defined borders. Overall pigmentation ranges from medium brown to almost black. As the child grows, the lesions become thicker and darker. Most giant congenital nevi ultimately have a verrucous or papillomatous surface. Satellite nevi often exist at the periphery, and most patients have numerous pigmented lesions (nevi and cafb-au-lait spots) diffusely located on the body. More than 95% of the lesions have associated coarse, brown or black hairs.17,31 Giant hairy nevi of the head, neck, or lumbosacral area may be associated with leptomeningeal melanocytosis (Fig. 5). This melanocytosis may be asymptomatic or may lead to hydrocephalus, seizures, focal neurologic deficits, or mental retardation. The symptoms of leptomeningeal melancytosis generally present within the first 2 years of life, with signs of increased intracranial pressure and spinal cord compression, such as lethargy, irritability, headache, recurrent vomiting, seizures, bulging fontanelles, photophobia, or papilledema. Spinal defects, such as meningomyelocele and spina bifida, can be associated with CNN overlying the vertebral column. Children with multiple nevi or large nevi of the head, neck, or posterior midline should be assessed with magnetic resonance imaging and receive baseline neurologic e~aluation.~, 17, 31 The surgical removal of small CNNs remains cpntroversial because of the unclear malignant potential. The risk for malignant transformation in small CNNs has been reported variably from 0% to 8% over a lifetime. This disparity may be caused by the difficulty in defining these lesions both clinically and 32, For clinicians who agree on the malignant potential, approhist~logically.~~~ priate treatment includes surgical excision. Removal should be performed before the onset of puberty because the risk for melanoma in small CNNs increases at that time34;however, the ability of children and parents routinely to observe small CNNs for changes and the cosmetic sensitivity of leaving the CNN on the skin versus the potential scar from removal should all be considered in making a surgical decision (Fig. 6). Lesions can be improved cosmetically with laser ablation, but this treatment does not wholly eliminate the risk for melanoma because CNNs have melanocytes deep in the dermis that are not removed by laser. There is general agkeement that giant congenital nevi are precursors of malignant melanoma, with lifetime risks ranging from 5% to 15%, for lesions present at birth.15 Recently, a 1000-fold increase in the risk of melanoma mortality was found in children with CNNs larger than 20 cm or covering more than 5% of their body surface areas.4O In contrast to small CNNs, there is a risk for malignant transformation of giant CNNs before the age of 10 years, with some reports indicating increased risk in the first 5 years.32Because of the high risk for melanoma in these patients, many advocate prophylactic excision of the entire nevus, usually performed in stages. This option is not always viable because the size and location of the CNN can make removal cosmetically impractical or physically impossible. Recent reports indicate good cosmetic results with the Q-switched neodymium-yttrium-aluminum-garnet (Nd:YAG), Q-switched ruby, and normal-mode ruby Again, because deep melanocytes are not eliminated, the risk for malignant transformation is still present. Whether medium CNNs carry the small risk for small CNNs or the significant risk for giant CNNs is unclear; however, acquired melanocytic nevi do not
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carry the risk for development of melanoma that CNNs, in general, do. Therefore, routine surgical removal of acquired melanocytic nevi is not indicated. Assessment of suspicious pigmented lesions requires evaluation of five observable features (the ABCDEs of melanoma) listed as follows:
A: Asymmetry of lesion B: Border of lesion irregular C: Color of lesion varied, especially red, white, and blue D: Diameter of more than 6 mm E: Elevation focally within flat lesion An asymmetric lesion cannot be folded into equal halves. An irregular border should raise suspicion. Surprisingly, the darkness of the pigment is not necessarily suspect if it is homogeneous throughout the lesion. Rather, it is the variability of color within the lesion that should raise flags. Shades of tan, brown, and black, as well as variations on red, white, and blue, can be seen in melanomas. Melanomas traditionally are said to be more likely if the lesion has a diameter of larger than 6 mm, or about the size of a pencil eraser; however, melanomas are now being caught earlier, even as the incidence rises. One must recognize that melanomas start smaller before they get to the more worrisome 6-mm threshold. Finally, elevation refers to focal growth within a flatter lesion, suggesting nodular growth in a superficial spreading melanoma. Although the development of melanomas in childhood is extremely rare, the incidence of melanomas in adults is increasing. The incidence in the pediatric population starts increasing after the age of 12 years.25Education of children and their parents about the risks of sun exposure and subsequent development of skin disorders, including melanomas, is important because it is estimated that children get 80% of their lifetime sun exposure by the age of Risks for developing malignant melanoma over a lifetime are as follows:
Family history of melanoma Congenital nevomelanocytic nevi Greater than average number of acquired moles Red hair color Skin type that always bums, never tans Severe sunburns during childhood Xeroderma pigmentosum Family history of atypical mole syndrome Tyrosinase negative albinism Routine self-examinationsare recommended for all patients. Those at risk should have complete skin examinations by a dermatologist and instructed and encouraged to perform self-examinations on a regular basis. Port-Wine Stains and the Use of Lasers in Children
Port-wine stains are congenital vascular malformations that occur in 0.3% to 0.5% of newborns and typically involve the face and neck, although any body surface can be involved. Lesions are most commonly unilateral and often follow the distribution of a cutaneous nerve, especially when involving the face. They are present at birth, persist throughout life, and grow in proportion to the affected childla,26, 39 as opposed to hemangiomas, which are generally not present at birth, often grow rapidly over the first few months, and gradually involute over 2 to 9 years of age.
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Initially, port-wine stain lesions appear as pink or red macules. In time, port-wine stains become progressively darker and more elevated (see article by Fishman and colleagues, this issue). Mature lesions often appear as red-purple plaques with papular or nodular areas. They are often associated with underlying tissue hypertrophys, 39 These lesions represent vascular ectasias involving the venules, capillaries, and possibly neural elements of the dermis. After about 10 years of age, vascular ectasia appears in deeper portions of the dermis and sometimes involves the subcutaneous tissue.', 39 A few patients with port-wine stains may have associated syndromes. Five percent to 8% of newborns with facial port-wine stains have Sturge-Weber syndrome, characterized by distribution of the malformation in the first branch of the trigeminal nerve and vascular malformation of the ipsilateral eye, meninges, and cerebral cortex. Associated findings include glaucoma, mental retardation, seizures, and hemiplegia.I8,35, 39 Klippel-Trenaunay syndrome involves portwine stains most commonly on an extremity, associated with underlying venous varicosities and hypertrophy of the bone and soft tissue in the affected area. Klippel-Trenaunay syndrome with the presence of arteriovenous fistulas is called Parkes-Weber syndrome.', l8 Treatment of port-wine stains before lasers included surgical excision, cryo39 The surgery, radiation therapy, flesh-colored tattoos, and cosmetic cover-up.35, current treatment of choice is the flashlamp-pulsed dye laser (FPDL). The FPDL was developed to work by selective photothermolysis. Originally, a 577-nm yellow light was used to coincide with the longest absorption peak of oxyhemoglobin. Currently, a 585-run yellow light is used with a pulse duration of 450 ms, which penetrates deeper-with no apparent loss in target specificity. There is a minimal risk for scarring?, 26 Disadvantages include posttreatment purpura, which tends to resolve in 5 to 15 days, and hyperp-igmentation,which generally 37 Other lasers used for port-wine stains with good resolves in 2 or 3 results are the argon pulsed dye, copper vapor, Nd:YAG, and the potassium titanyl phosphate (KTP) crystal that converts the 1064-run Nd:YAG into the 532 v e r ~ i o n . ~ Lasers used in dermatology target the three main skin chromophores (i.e., oxyhemoglobin, hemoglobin, and melanin) for selective photothermolysis to achieve changes in skin lesions. The argon laser has been used to treat telangiectasias, hemangiomas, and port-wine stains, but its use in children is now limited because of a high incidence of hypertrophic scarring.36,37 The FPDL, in addition to its use for port-wine stains, is used for telangiectasias,hemangiomas, pyogenic granulomas, common and genital warts, and hypertrophic scars. Lasers that target melanin can be used to treat freckles, caf6-au-lait spots, Becker 's nevi, congenital and acquired nevomelanocytic nevi, and the dyspigmentation of nevus of Ota and Ito. Pigment located within the dermis responds best to the Q-switched ruby laser. Tattoos also respond well to Q-switched lasers. Darker, amateur tattoos are the easiest lesions to remove, requiring fewer treatments for complete response.36,37 One important issue when using lasers in children is anesthesia. Many have likened the pain of laser treatment to a rubber band snapping against the skin. Although tolerated by many adults and older children, it is frightening for younger children and infants. Larger, deeper lesions may require multiple passes, making it difficult even for adolescents to tolerate without anesthesia. Topical anesthetics, local intralesional injections, nerve blocks, oral or intravenous sedation, and general anesthesia are all viable options.37 A recent study demonstrated the safety and advantages of using general anesthesia when treating port-wine stains in children. This use of general anes-
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thesia led to the use of more pulses per session, resulting in larger treatment area; safe treatment of upper and lower eyelids with insertion of stainless steel eyeshields; decreased unexpected movements of children, resulting in fewer overlapped areas and less scarring; and children being treated at a younger age.12
Surgical procedures on the skin are commonplace in the practice of pediatric dermatology. Dermatologists are trained in their residencies to perform office surgery, including biopsies, excisions with repairs, cryosurgery, chemosurgery, and laser surgery. Although most dermatologists treat patients of all ages, some treat children only. Within this group, some are concentrating on pediatric dermatologic surgery. Many dermatologists take additional training in dermatologic and laser surgery, treating both adults and children. New techniques and developing technology present pediatricians and dermatologists with many options in choosing the best and most appropriate treatment modalities. References 1. Calonje E, Wilson-Jones E: Vascular tumors: Tumors and tumor-like conditions of blood vessels and lymphatics. In Elder D, Elenitsas R, Jaworsky C, et a1 (eds): Levers Histopathology of the Skin, ed 8. Philadelphia, Lippincott-Raven, 1997 2. Cohen BA, Prose N, Schachner LA: Acne. In Schachner LA, Hansen RC (eds): Pediatric Dermatology, ed 2. New York, Churchill Livingstone, 1995, pp 673-674 3. Crollick JS, Klein LE: Punch biopsy diagnostic technique. J Dermatol Surg Oncol 13839, 1987 4. DeDavid M, Orlow SJ, Provost N, et a1 Neurocutaneous melanosis: Clinical features of large congenital melanocytic nevi in patients with manifest central nervous system melanosis. J Am Acad Dermatol35529-538, 1996 5. Doyle E, Freeman J, Im NT, et a1 An evaluation of a new self-adhesive patch preparation of amethocaine for topical anaesthesia prior to venous cannulation in children. Anaesthesia 481050-1052, 1993 6. Drolet B, Prendiville J, Golden J, et a 1 Membranous aplasia cutis with hair collars. Arch Dermatol 131:1427-1431, 1995 7. Elsner , ' l Dummer R Signs of methaemoglobinaemia after topical application of EMLA cream in an infant with haemangioma. Dermatology 195:153-154, 1997 8. Emst AA, Pomerantz J, Nick TG, et a 1 Lidocaine via iontophoresis in laceration repair: A preliminary safety study. Am J Emerg Med 13:17-20, 1995 9. Garden JM, Bakus A D Laser treatment of port-wine stains and hemangiomas. Dermato1 Clin 15:373-383, 1997 10. Greenbaum SS, Bernstein E F Comparison of iontophoresis of lidocaine with a eutectic mixture of lidocaine and prilocaine (EMLA) for topically administered local anesthesia. J Dermatol Surg Oncol20:579-583, 1994 11. Grevelink JM, van Leeuwen RL, Anderson RR, et a1 Clinical and histological responses of congenital melanocytic nevi after single treatment with Q-switched laser. Arch Dermatol 13339-353, 1997 12. Grevelink JM, White VR, Bonoan R, et a1 Pulsed laser treatment in children and the use of anesthesia. J Am Acad Dermatol377.!j-81, 1997 13. Gupta AK, Sibbald RG, Lynde CW, et ak Onychomycosis in children: Prevalence and treatment strategies. J Am Acad Dermatol 36:395-402, 1997 14. Habif TP (ed): Dermatologic surgical procedures. In Clinical Dermatology: A Color Guide to Diagnosis and Therapy, ed 2. St. Louis, CV Mosby, 1990, p 666,678 15. Harley S, Walsh N A new look at nevus-associated melanomas. Am J Dermatopathol 18~137-141,1996
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16. Hurwitz S (ed): Cutaneous disorders of the newborn. In Clinical Pediatric Dermatology: A Textbook of Skin Disorders of Childhood and Adolescence, ed 2. Philadelphia, WB Saunders, 1993 17. Hunvitz S (ed): Cutaneous tumors in childhood. In Clinical Pediatric Dermatology: A Textbook of Skin Disorders of Childhood and Adolescence, ed 2. Philadelphia, WB Saunders, 1993 18. Hurwitz S (ed): Vascular disorders of infancy and childhood. In Clinical Pediatric Dermatology: A Textbook of Skin Disorders of Childhood and Adolescence, ed 2. Philadelphia, WB Saunders, 1993 19. Hurwitz S (ed): Viral diseases of the skin. In Clinical Pediatric Dermatology: A Textbook of Skin Disorders of Childhood and Adolescence, ed 2. Philadelphia, WB Saunders, 1993 20. Kopf AW, Bart RS, Hennessey P: Congenital nevocytic nevi and malignant melanoma. J Am Acad Dermatol 1:123-130, 1979 21. Lawson RA, Smart NG, Gudeon AC, et a1 Evaluation of an amethocaine gel preparation for percutaneous analgesia before venous cannulation in children. Br J Anaesth 75:282-285, 1995 22. Leboucq N, Montoya y, Martinez P, Montoya-Vigo F, et al: Aplasia cutis congenita of the scalp with-large underlying skull defects: A case report. Neuroradiology 36:480482, 1994 23. Leffell DJ, Brown MD (eds): Skin biopsy. In Manual of Skin Surgery, A Practical Guide to Dermatologic Procedures. New York, Wiley-Liss, 1997 24. Lener EV, Bucalo BD, Kist DA, et al: Topical anesthetic agents in dermatologic surgery: A review. Dermatol Surg 23673483,1997 25. Levine N. Pigmentary abnormalities. In Schachner L& Hansen RC: Pediatric dermatology, ed 2. New York, Churchill Livingstone, 1995, p 562 26. McCaffertv DF, Woolfson AD, Handlev 1, et a1 Effect of uercutaneous local anesthetics on pain riduction during pulse dye l&er treatment of port-wine stains. Br J Anaesth 78286-289,1997 27. Micali G, Guitart J, Bene-Bain MA, et al: Genodermatoses. In Schachner LA, Hansen RC (eds): Pediatric Dermatology, ed 2. New York, Churchill Livingstone, 1995 28. Ng WK: Nevus sebaceus with apocrine and sebaceous differentiation. Am J Dermatopathol 18:420-423, 1996 29. Nunez M, Miralles ES, Boixeda P, et a1 Iontophoresis for anesthesia during pulsed dye laser treatment of port-wine stains. Pediatr Dermatol 14397400, 1997 30. Quinn J, Wells G, Sutcliffe T, et al: A randomized t i a l comparing octylcyanoacrylate tissue adhesive and sutures in the management of lacerations. JAMA 2771527-1530, 1997 31. Rhodes AR Neoplasms: Benign neoplasias, hyperplasias, and dysplasias of melanocytes. In Fitzpatrick TB, Eisen AZ, Wolff K (eds): Dermatology in General Medicine, ed 4. New York, McGraw-Hill, 1993 32. Ruiz-Maldonado R, Orozco-Covanubias M Malignant melanoma in children. Arch Dermatol 133:363-371, 1997 33. Salasche SJ: Surgery. In Scher RK, Daniel CR (eds): Nails: Therapy, Diagnosis, Surgery. Philadelphia, WB Saunders, 1990 34. Schleicher SM, Lim SJM: Congenital nevi. Int J Dermatol 342325429, 1995 35. Sherwood KA: The use of topical anesthesia in removal of port-wine stains in children. J Pediatr 122(suppl):36-41, 1993 36. Spicer MS, Goldberg DJ: Laser in dermatology. J Am Acad Dermatol 34:l-25, 1996 37. Spicer MS, Goldberg DJ, Janniger CK: Lasers in pediatric dermatology. Cutis 55:270272, 278-280, 1995 38. Stem RS, Weinstick MC, Baker SG: Risk reduction for non-melanoma skin cancer with childhood sunscreen use. Arch Dermatol 122:537, 1986 39. Strauss RP, Resnick SD Pulsed dye laser therapy for port-wine stains in children: Psychosocial and ethical issues. J Pediatr 122505-510,1993 40. Swerdlow AJ, English JSC, Qiao Z : The risk of melanoma in patients with congenital nevi: A cohort study. J Am Acad Dermatol 32595599, 1995
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41. Taddio A, Stevens B, Craig K, et al. Efficacy and safety of lidocaine-prilocaine cream for pain during circumcision. N Engl J Med 3361197-1201, 1997 42. Tong AKF, Vickers C F H Topical noncorticosteroid therapy. In Fitzpatrick TB, Eisen AZ, Wolff K, et a1 (eds): Dermatology in General Medicine, ed 4.New York, McGrawHill, 1993 43. Ueda S, Imayama S: Normal-mode ruby laser for treating congenital nevi. Arch Dermatol 133:355-359, 1997 44. Vazquez M, Sanchez JL: Nevus sebaceus: Clinical outcome and considerations for prophylactic excision. Int J DermatolN538-541, 1995 45. Wagner AM, Hansen RC: Neonatal skin and skin disorders. In Schachner LA, Hansen RC (eds): Pediatric Dermatology, ed 2. New York, Churchill Livingstone, 1995, p 295 46. Wheeland RG: Surgical techniques. In Schachner LA, Hansen RC (eds): Pediatric Dermatology, ed 2. New York, Churchill Livingstone, 1995 47. Zeltzer L, Regalado M, Nichter LS, et al: Iontophoresis versus subcutaneous injection: A comparison of two methods of local anesthesia delivery in children. Pain M73-78, 1991 Address reprint requests to Jill S . Crollick, EdM, MD Department of Dermatology State University of New York at Buffalo 100 High Street, C-319 Buffalo, NY 14203 e-mail:
[email protected]