Hyperthyroidism (Graves' disease)

W

hen the thyroid gland excretes excessive amounts of thyroid hormone, the ensuing hyperthyroidism may result from either a congenital or an acquired condition. Congenital hyperthyroidism (neonatal thyrotoxicosis) occurs almost always in infants born to mothers with Graves’ disease (autoimmune thyrotoxicosis), which is the name usually given to acquired hyperthyroidism. Graves’ disease is caused by an autonomous hype&unction of the thyroid gland. The thyroid is stimulated by thyroid-stimulating immunoglobulin, which binds to the thyroid-stimulating hormone receptors on the thyroid cells, causing a stimulating effect (Donohoue, 1990). It occurs four times more often in females than males. Graves’ thyrotoxicosis is rare in children and adolescents. The incidence is generally reported as 0.8 per 100,000 children per year. It should be noted, however, that 95% of those children who are thyrotoxic have Graves’ disease in contrast to hyperthyroidism in adults, which may be attributed to a number of other causes (Perrild and Jacobsen, 1996). Graves’ disease in childhood is a self-limiting disorder with a reported remission rate of 25% every 2 years. (Lippe, Landow, & Kaplan, 1987). Neonatal hyperthyroidism is due to transplacental passage of mater-

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nal hyperthyroidism-related immunoglobulins. Although only 1% to 2% of infants born to mothers with Graves’ disease are affected, the mortality rate for those infants is as high as 25%, and there is a significant immediate and long-term morbidity that may include craniosynostosis and developmental delay (Skuza, Sills, Stene, & Rapaport, 1996). A problem that may exist in detecting neonatal signs and symptoms relates to the current practice of early discharge after birth. Signs and symptoms of hyperthyroidism may not appear until several or many days after delivery. Although maternal third semester and cord immunoglobulin levels do correlate with hyperthyroidism, this is not always true; therefore some cases may be missed in the hospital. The usual symptoms of hyperthyroidism in infants include tachycardia, appearing jittery, and difficulty feeding. Thyroid tests reveal elevated serum levels of T4, free T4, and Ts with suppressed serum thyrotropin levels. These findings were found in all the infants studied between 1 and 29 days after birth (Skuza, Sills, Stene, & Rapaport, 1996). The affected infants all had

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initial thyrotropinreceptor antibody levels greater than 0.25. An elevated thyrotropinreceptor antibody value along with clinical and biochemical signs suggest hyperthyroidism, and this information is useful in screening infants of mothers with Graves’ disease. Children with hyperthyroidism have the following signs and symptoms: goiter (enlarged thyroid), restlessness, increased sweating, heat intolerance, nervousness, increased appetite but a weight loss, diarrhea, tremor, tachycardia, hypermetabolic rate, eyelid lag, widened pulse pressure, and insomnia. Sometimes children exhibit behavior problems or diminished school performance. The ophthalmopathy seen in children is generally less severe than that seen in adults. Adults often present with exopthalmia, which is not common in children. The diagnosis of Graves’ disease is based on the combination of clinical signs and symptoms and the elevation of thyroid hormone levels. The thyroid hormone profile usually shows an elevated total T4, free T4, and T3 levels and very low or undetectable levels of thyroid-stimulating hor-

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GROWTH & DEVELOPMENT

mone (Donohoue, 1990). If undetected or untreated, increased thyroid hormone may cause accelerated growth (Connaughty, 1992). Thyroid function abnormalities have also been associated with a variety of psychiatric symptoms such as anxiety, mood lability, mania, hyperactivity, and depression (Leo, Batterman-Fauna, Pickhardt, Cartagena, & Cohen, 1997). The inv&igators in this study (Leo et al., 1997) concluded that routine thyroid screening among adolescent psychiatric inpatients is not warranted except for patients with physical signs or symptoms associated with thyroid disease. Because a palpable thyroid nodule or goiter suggests thyroid dysfunction, palpation of the neck is a cost-effective and efficient screen for adolescent thyroid dysfunction. However, Leo et al. (1997) do recommend that even if neck palpation is negative, thyroid function testing should be considered in patients with short stature, delayed puberty, abnormalities in blood pressure and heart rate, uterine bleeding or amenorrhea, a family history of thyroid disease, or symptoms suggesting autoimmune disease. There are three major treatments for hyperthyroidism: anfithyroid drugs, surgery, or radioiodine. The first treatment of choice is the use of antithyroid drug therapy. Antithyroid drugs might be given in combination with T4 or adapted as the clinical response changes (Perrild & Jacobson, 1996). Methimazole (Tapazole) or propylthiouracil are the usual antithyroid medications prescribed. Both block the production of T4, but propylthiouracil also blocks the peripheral decodination of T4 to T3 (Donohoue, 1990). Methimazole is often preferred because it has a longer serum half-life and because the effective dose is approximately one tenth the propylthiouracil dose

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(Donohoue, 1990). Toxic side effects and compliance are problems encountered in some children receiving drug treatment. The side effects of drug therapy are relatively minor such as skin rashes and urticaria. The most serious side effect seen is granulocytopenia. Compliance problems may occur because treatment with drugs may extend over long periods of time, and children just become tired of the regimen. In Europe, the second treatment of choice is subtotal or total thyroidectomy. Rudberg et al. (1996) conducted a study of children and adolescents with Graves’ disease residing in Uppsala, Sweden. Their findings indicate that surgery should be considered when permanent euthyroidism cannot be achieved after approximately a lyear period of medical (drug) therapy. Surgery today is usually associated with few complications, and surgery can end the thyrotoxic effects quite rapidly, often within a few days. The surgery advocated for children should be radical-often a total thyroidectomy (Rudberg, Johansson, Akerstrom, Tunetoo, & Karlson, 1996). The mount of thyroid tissue left behind is determined by the amount necessary to protect the parathyroid glands and the recurrent laryngeal nerves (Soreide, van Heerden, Lo, Grant, Zimmerman, & Ilstip, 1996). The outcome of the surgery has been found to be dependent on the size of the thyroid remnant left and the severity of the disease as reflected in the prevailing thyroid-stimulating hormone receptor antibody titers. This surgery requires a meticulous operative field free from unnecessary bleeding and the early identification of the parathyroid glands during surgery. Skillful operative treatment can be performed with low morbidity and no mortality. In the United States, radioactive iodine therapy (,,,I) is the second

treatment of choice. This treatment has not been widely accepted in Europe. The use of radioactive iodine in children has been limited because of a theoretic risk of cancer of the thyroid or other malignancies. Current data do not support the theoretic risk of the child having cancer or leukemia, and radioactive iodine does not appear to increase the risk of future birth effects in th e patient’s offspring (Donohoue, 1990). Radioiodine ablative therapy remains the therapy of choice in older children and adults in the United States because there is a low relapse rate with an ablative dose (Perrild & Jacobsen, 1996). In fact, approximately 60% to 90% of patients treated with 1311 were found to have hypothyroidism in follow-up sktdies. Long-term studies are required to determine whether therapies directed at alternating the autoimmune abnormalities will offer greater success. Pediatric nurse practitioners must be alert to the possibility of Graves’ disease in children and must be able to assess and refer for appropriate evaluation. Children receiving treatment must be educated in an attempt to foster compliance, and they must be monitored for a long period of time after treatment.

REFERENCES Connaughty, MS. (1992). Accelerated growth in children. Jouv~al of Pediatric Health

Cave, 6,316-24.

Donohoue, l? (1990). The thyroid gland. In F. A. O&i, C. D. DeAngelis, R.D. Fergin, & J.B. Warshaw (Eds.), Principles and prucLice of pediatrics (pp. 1816-24). Philadelphia: J.B.Lippincott Company. Leo, R.J.,Battennan-Faunce, J.M., Pickhardt, D., Cartagena, M., & Cohen, G. (1997). Utility of thyroid function screening in adolescent psychiatric inpatients. Journal of the American lescent Psychiatry,

Academy

of Child and Ado-

36,103-111.

JOURNAL OF PEDIATRIC HEALTH CARE

Ip@IGROWTH Lippe,

B.M.,

Landaw,

E.M.,

(1987).

Hyperthyroidism

treated

with

longterm

Twenty-five

percent

years. Jouvnal ofCIinicul Metabolism, Perrild,

& Kaplan, in medical

remission

S.A.

in childhood.

ofEndocrinology,

Rudberg,

C., Johansson,

children

Tuvemo,

therapy.

Graves’

every

Endocvimlogy

H., Akerstrom,

T., & Karlsson, disease

F.A.

in children

cents. Late results

of surgical

and

European

of Endocrinology,

Journal

G., (1996).

and adoles-

two

64,1241-5.

H., & Jacobsen,

toxicosis

Castiglia

& DEVELOPMENT

treatment. 134,

710-5. B.B. (1996).

Thyro-

European

Journal

134,678-9.

Skuza, port,

Graves’

K.A.,

Sills, LN.,

Stene,

R. (1996). Prediction in infants

M., & Rapaof neonatal

born

hy-

disease.

The Journal

of Pedi-

atrics, 128,264-B. Soreide,

J.A.,

van

Heerden,

J.A.,

Lo, C.Y.,

Grant,

C.S., Zimmerman,

D., & Ilstrup,

D.M.

(1996).

Surgical

treatment

of

in patients

younger

than

Journal

of Surgery,

Graves’

perthyroidism

Care of the Umbilical

with

18

disease

years. World

20,

794-9.

to mothers

Cord

Although most parents are conscientious about applying alcohol to their newborn infant’s umbilical cord, often the hard dried tissue that first forms on the top part of the cord turns into a “plug” and slows down the drying of the cord closest to the abdomen. This results in a moist sinewy string keeping the cord attached. The following method hastens the drying of the cord. Soak a cotton ball with isopropyl alcohol until it is moderately moist. Find the end of the cotton ball and unroll it into its original flat fibrous length. Then twist this length of cotton fiber into a rope. Pull the partially dried umbilical cord up and away from the baby’s abdomen. While keeping the cord taut, wrap the alcohol-moistened cotton rope around the moist umbilical string several times. Instruct the parents to leave this on for several hours and repeat several times a day. This allows the alcohol to wick away the moisture in the portion of the cord closest to the abdomen, causing the cord to fall off. BeckyMorrison, MSN, RN, CPNP Johnson City, Tennessee 25/S&4249

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