Propylthiouracil Induced Neutropenia in Thyroid Storm: A Case Requiring Urgent Total Thyroidectomy.

Thyroid storm is a rare but life-threatening complication of hyperthyroidism that requires urgent management. While propylthiouracil (PTU) is a key treatment, it carries multiple risks, including potentially fatal risk of agranulocytosis. We report a 40-year-old female with Graves' disease who presented with thyroid storm and compressive goiter. High-dose PTU (1 g loading dose followed by 200 mg every 4 hours) was initiated; however, severe neutropenia (ANC: 0.22×10ˆ3/µL) developed within 48 hours, necessitating immediate drug discontinuation. Bridging therapy with hydrocortisone, cholestyramine, Lugol's solution, was implemented once available, and low-dose carbimazole was cautiously reintroduced under close monitoring without recurrence of neutropenia. Once a euthyroid state was achieved, definitive management with a total thyroidectomy was performed without complications. This case highlights three key learning points: (1) agranulocytosis can occur very early during high-dose PTU therapy; (2) careful bridging strategies are essential to prevent rebound thyroid storm after antithyroid drug withdrawal; and (3) timely transition to definitive surgical management can be lifesaving when antithyroid drug intolerance occurs.