Hypothyroidism%20(pediatric) Signs and Symptoms

• Congenital hypothyroidism is one of the most common preventable causes of mental retardation
• Acquired hypothyroidism is the absence or decrease in the production of thyroid hormone

Acquired Hypothyroidism

• Primary acquired hypothyroidism: Caused by generalized tissue resistance to thyroid hormone and disorders that affect the thyroid gland directly
  • Responsible for majority of hypothyroid cases
  • Etiologies: Chronic autoimmune (Hashimoto’s) thyroiditis, iodine deficiency/excess, thyroid surgery, radioactive iodine therapy, external irradiation, infiltrative disorders, drugs, agenesis/dysgenesis of the thyroid
  • Is further classified into subclinical and overt hypothyroidism

• Central acquired hypothyroidism: Caused by hypothalamic or pituitary disorders
  
  • Characterized by defective thyroid hormone production secondary to insufficient stimulation by TSH of an otherwise normal thyroid gland 
  • Etiologies: Pituitary tumors, metastasis, hemorrhage, necrosis, aneurysms, surgery/trauma, infiltrative disorders, infectious diseases, chronic lymphocytic hypophysitis, other brain tumors, congenital abnormalities, defects in thyrotropin-releasing hormone (TRH), thyroid-stimulating hormone (TSH) or both

• May also be classified as congenital or acquired (symptoms manifest after a period of normal functioning)

Congenital Hypothyroidism

• Permanent cases result from dysgenesis/agenesis of thyroid gland or a defect in thyroid hormonogenesis
• Transient cases due to transplacental passage of maternal medication, maternal blocking antibodies or iodine deficiency/excess
• Rare cases due to central hypothyroidism

Acquired Hypothyroidism

• Goiter
• Lethargy, ataxia, dull facial expressions
• Slow growth and short stature, delayed bone age and dentition
• Immature upper to lower body proportions
• Cool, dry, jaundiced skin; dry, coarse hair, brittle nails
• Obstructive sleep apnea (OSA)
• Cold intolerance
• Constipation, galactorrhea
• Hoarseness
• Memory and mental impairment, decreased concentration, depression
• Precocious sexual development, irregular or heavy menses, infertility
• Hyperlipidemia
• Myxedema
• Weight gain despite decreased appetite
• Bradycardia

Congenital Hypothyroidism

• Large fontanelles
• Prolonged indirect jaundice, constipation
• Hypothermia; cool, dry skin
• Noisy respirations, hoarse cry
• Goiter
• Delayed relaxation of deep tendon reflexes, decreased activity level
• Elevated birth weight despite poor feeding
• Pooling of secretions, large protruding tongue
• Myxedema of eyelids, hands, scrotum
• Bradycardia