A Case of Acute Liver Failure Secondary to Thyrotoxicosis

Thyroid storm is a rare, life-threatening endocrine emergency that can cause multiorgan dysfunction, although acute liver failure (ALF) remains an uncommon manifestation. A 52-year-old woman with Graves' disease who had discontinued methimazole presented with three days of nausea, vomiting, diarrhea, melena, generalized weakness, and chest pain. She was lethargic and tachycardic, with a diffusely enlarged thyroid gland, warm skin, bilateral hand tremors, and hypoglycemia. Laboratory testing demonstrated severe thyrotoxicosis, marked hepatocellular injury with an aspartate aminotransferase concentration of 1,059 units per liter (U/L) and an alanine aminotransferase concentration of 955 U/L, and an international normalized ratio of 7.8. Echocardiography showed a left ventricular ejection fraction of 25%-30%, while coronary angiography was normal, and evaluation for viral, autoimmune, and structural hepatobiliary disease was unrevealing. Treatment with hydrocortisone, propranolol, and methimazole resulted in clinical improvement and substantial biochemical recovery, with normalization of the hepatic and thyroid biochemical parameters at two-month follow-up. This case emphasizes the importance of considering thyroid storm in patients with ALF and promptly evaluating both thyroid-mediated and hemodynamic contributors to hepatic injury.