Neonatal thyrotoxicosis presenting with heart failure

Thyrotoxicosis in the newborn is usually the result of the passage of thyroid stimulating antibodies from the mother to the fetus. This is a case report of a ten-day-old male neonate who presented with signs of neonatal thyrotoxicosis and heart failure. He had a high T3 (>7.7nmol/l), high T4 (> 300nmol/l), and low TSH (0.14 uIU/ml). He was hospitalized at the neonatal intensive care unit of Myungsung Comprehensive Specialized Hospital and was successfully treated with propylthiouracil, propanolol, furosemide, lugols iodine, hydrocortisone, and supportive care. Clinical features and management of neonatal thyrotoxicosis are discussed with a literature review.