pediatrics
Hypothyroidism in Infants and Children
Symptoms and Signs
Symptoms and signs of hypothyroidism in infants and young children differ from those in older children and adults. If fetal iodine deficiency occurs very early during pregnancy, infants may present with severe growth failure, coarse facial features, intellectual disability, and spasticity. Most other hypothyroid infants initially have few if any symptoms or signs and are detected only through newborn screening. Symptoms that do occur may be subtle or develop slowly because some maternal thyroid hormone crosses the placenta. However, after the maternal thyroid hormone is metabolized, if the underlying cause of hypothyroidism persists and hypothyroidism remains undiagnosed or untreated, it usually slows central nervous system development moderately to severely and may be accompanied by low muscle tone, sensorineural hearing loss, prolonged hyperbilirubinemia, umbilical hernia, respiratory distress, macroglossia, large fontanelles, poor feeding, and hoarse crying. Rarely, delayed diagnosis and treatment of severe hypothyroidism lead to intellectual disability and short stature. Some symptoms and signs of hypothyroidism in older children and adolescents are similar to those of adults (eg, weight gain; fatigue; constipation; coarse, dry hair; sallow, cool, or mottled coarse skin— see Symptoms and Signs ). Signs specific to children are growth retardation, delayed skeletal maturation, and usually delayed puberty. 