Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features ++ Growth retardation, decreased physical activity, weight gain, constipation, dry skin, cold intolerance, and delayed puberty Untreated congenital hypothyroidism: thick tongue, large fontanels, poor muscle tone, hoarseness, umbilical hernia, jaundice, and severe neurocognitive impairment T4, FT4, and T3 resin uptake are low Thyroid-stimulating hormone (TSH) levels are elevated in primary hypothyroidism +++ Clinical Findings ++ Even when the thyroid gland is completely absent, most newborns with congenital hypothyroidism appear normal However, because congenital hypothyroidism is associated with intellectual impairment, thyroid testing is included in the newborn screen and treatment must be initiated as early as possible Jaundice associated with an unconjugated hyperbilirubinemia may be present in newborns with congenital hypothyroidism Features of juvenile hypothyroidism include Short stature, abnormal weight gain Delayed bone age and retarded dental eruption Skin changes (dry, thick, scaly, coarse, pale, cool, or mottled, or have a yellowish tinge) Hair changes (dry, coarse, or brittle), hair loss, lateral thinning of the eyebrows Musculoskeletal findings (hypotonia and a slow relaxation component of deep tendon reflexes) Physical and mental sluggishness Nonpitting myxedema Constipation Cold temperature intolerance Bradycardia Delayed puberty; occasional pseudopuberty In hypothyroidism resulting from enzymatic defects, ingestion of goitrogens, or chronic lymphocytic thyroiditis, the thyroid gland may be enlarged Thyroid enlargement in children is usually symmetric, and the gland is moderately firm and not nodular +++ Diagnosis ++ In primary hypothyroidism Total T4 and FT4 may be normal or decreased Serum TSH is elevated Circulating autoantibodies to thyroid peroxidase and thyroglobulin may be present In central hypothyroidism TSH is usually inappropriately normal and associated with a low total T4 and FT4 Serum prolactin may be elevated, resulting in galactorrhea Other pituitary deficiencies may be present Thyroid imaging, while helpful in establishing the cause of congenital hypothyroidism, does not affect the treatment plan and is not necessary All newborns should be screened for congenital hypothyroidism shortly after birth +++ Treatment ++ Levothyroxine (75–100 μg/m2/d) is the drug of choice for acquired hypothyroidism In neonates with congenital hypothyroidism, the initial dose is 10–15 μg/kg/d Serum total T4 or FT4 concentrations are used to monitor the adequacy of initial therapy Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.