Abstract
RAIONALE: Myxedema coma (MC) is extremely rare but lethal in pediatric patients with hypothyroidism leading to altered mental status and hypothermia. But there is no clinical guideline for such cases. PATIENT CONCERNS: A 6-year-old Chinese girl presented with coma and hypothermia preceded by pneumonia. Her lab results were: free thyroxin (T4) 4.18 pmol/L and thyroid-stimulating hormone (TSH) > 150 μIU/mL with extremely elevated anti-thyroid peroxidase (TPO-Ab) and anti-thyroglobulin. Pneumonia, mild pleural, and pericardial effusion were seen on computed tomographic (CT) scan. DIAGNOSES: MC, autoimmune hypothyroidism, pneumonia and sepsis were diagnosed. INTERVENTION: Gastric levothyroxine, intravenous dexamethasone and antibiotics were administered. OUTCOME: Her consciousness was restored and temperature returned to normal 2 days after starting levothyroxine. She was discharged two weeks later. CONCLUSION: MC is rare but may be the initial presentation in pediatric patients with prolonged untreated hypothyroidism. Autoimmune thyroiditis could cause hypothyroidism in children. MC should be suspected in pediatric patients with altered mental status, hypothermia and cardiovascular instability. Treatment with 100 mg/m of gastric levothyroxine is an option for pediatric patients with MC.