Page 30 Complete Your CE Test Online - Click Here Nursing consideration: Since unrecognized or inadequately treated congenital hypothyroidism can have serious consequences nurses must be able to recognize the problem and be able to provide appropriate family education. Nurses must also be sure that newborns are appropriately screened. Incidence and etiology There are several types of hypothyroidism that affect children, including: ● ● Congenital hypothyroidism (CH): Occurs when the thyroid gland fails to develop or function normally before birth[12] . ● ● Acquired hypothyroidism-autoimmune hypothyroidism: Occurs as the result of an autoimmune disorder called chronic lymphocytic thyroiditis (CLT). In CLT the child’s immune system “attacks” the thyroid gland, causing damage and reduced functioning. Patients who have other types of autoimmune diseases (most often insulin- dependent diabetes) are at higher risk for developing CLT. It is estimated that 20% to 30% of people with diabetes will develop CLT. Thus, annual screening for CLT is often a routine part of diabetes care[12] . ● ● Acquired hypothyroidism-iatrogenic hypothyroidism: Occurs in people who have had their thyroid glands surgically removed or medically destroyed[12] . CH is a common problem, occurring in about one in every 2,500 to 3,000 babies. Currently, all states in the United States test for CH as part of the routine newborn screening initiatives[12] . ● ● Infantile cretinism (congenital or neonatal hypothyroidism) is three times more common in females than in males. Early diagnosis and treatment are essential for the best possible patient outcomes. If treatment begins before the age of 3 months the infant usually experiences normal growth and development. However, if treatment is not initiated within that timeframe and children remain untreated beyond the age of 2, irreversible mental retardation occurs. However, skeletal abnormalities are reversible with treatment[5] . Infant cretinism is most often the result of defective embryonic development of the thyroid gland. The next most common cause of the disorder is related to an inherited enzymatic defect in the synthesis of thyroxine (T4). Less often, anti-thyroid drugs administered during pregnancy cause cretinism in infants. Cretinism in children over the age of 2 is usually due to chronic autoimmune thyroiditis[5] . Complications of untreated hypothyroidism in children are severe mental retardation and skeletal malformations including dwarfism and bone and muscle dystrophy[5] . Clinical presentation At birth, the weight and length of the newborn with infantile cretinism appear normal. However, by the age of 3 to 6 months, the infant displays characteristic signs of hypothyroidism[5] . Hypothyroidism in children alert! Breast-fed infants with infantile cretinism experience a delayed onset of symptoms because breast milk contains small amounts of thyroid hormone[5] . Typical characteristics of hypothyroidism in children include the following signs[5,12] : The infant: ● ● Sleeps excessively and is inactive. ● ● Seldom cries, but when he/she does, the cry is hoarse. ● ● Has a lowered metabolism and progressive mental impairment. ○ ○ Exhibits abnormally deep tendon reflexes and hypotonic abdominal muscles. ○ ○ Has a puffy and swollen face and droopy eyelids. ○ ○ Has a short forehead, puffy, wide-set eyes, a broad, upturned nose, and a vacant, dull facial expression. ○ ○ Has a protruding abdomen. ○ ○ Has feeding problems. ○ ○ Displays slow, awkward movements. ○ ○ Has cold, coarse, dry, and thickened skin. ○ ○ Has dry brittle hair. ○ ○ Has a slow pulse rate and below normal body temperature. ○ ○ Becomes jaundiced because his/her immature liver cannot metabolism bilirubin. ○ ○ Has a large, protruding tongue that obstructs respirations, forcing him/her to breathe through the mouth. Hypothyroidism in children alert! Appropriate treatment for the child who acquires hypothyroidism after the age of 2 can prevent mental retardation. But growth retardation causes short stature, delayed epiphyseal maturation, and a head that looks unusually large because of the stunted growth of arms and legs[5] . Diagnosis Diagnosis is based on the results of thyroid function screening, which measures thyroid hormone and serum TSH levels. Hypothyroidism is diagnosed when TSH levels are above normal and thyroid hormone levels are below normal[12] . Thyroid scans and radioactive iodine uptake tests results show decreased uptake levels and the absence of thyroid tissue in children. Characteristic electrocardiogram changes are bradycardia and flat or inverted T waves in infants who have not received treatment. X-rays show an absence of the femoral or tibial epiphyseal line and significantly delayed skeletal development[5] . Treatment and nursing considerations Hypothyroidism in children (as well as adults) is generally treated with thyroid hormone replacements. Replacement therapy for children who are less than age one involves administration of oral levothyroxine. Initial doses are of moderate strength and are gradually increased to levels appropriate for life-long maintenance[5,12] . Hypothyroidism treatment alert! A too rapid increase in the dosage of thyroid hormone can trigger thyrotoxicity. Signs and symptoms of thyrotoxicity include tachycardia, vomiting, hypotension, tremor, weakness, shortness of breath, cough, swollen extremities, and coma. Thyrotoxicity can reach crisis levels (thyrotoxic crisis or thyroid storm) and is fatal without treatment that includes anti-thyroid medications, correction of electrolyte imbalance, and treatment of any cardiac arrhythmias[5,11] . Nursing consideration: Nurses must be aware that doses of thyroid replacement therapy are higher in children compared to adults because children metabolize thyroid hormone much more quickly[5] . Parents of children with hypothyroidism need support and encouragement as they learn to deal with their child’s need for life-long treatment and monitoring. Early detection and treatment are essential if mental retardation is to be avoided. Hypothyroidism alert! When working with parents of newborns be alert to any comments they may make about how “quiet” and “good” their babies are. Parents may mistake lack of activity, sleeping for long periods of time, and lack of crying as signs of a “good” baby, when these behaviors may actually indicate hypothyroidism[5] .