Synchronous Antithyroid Drug-Induced Agranulocytosis and Fournier Gangrene

ABSTRACT Objective: Antithyroid drugs (ATDs) such as thioimidazoles (e.g., methimazole, also called thiamazole, and carbimazole) and propylthiouracil are commonly used for the treatment of hyperthyroidism. A life-threatening reaction is agranulocytosis with an incidence of 0.1 to 0.5%. There are very few cases in the literature showing that the intake of ATDs finally led to sepsis with accompanying tissue necrosis. Methods: We present an unusual case of severe symptomatic agranulocytosis with sudden development of Fournier gangrene in a patient who was treated with ATDs for hyperthyroidism due to Graves disease. Results: A 69-year-old female was referred to our hospital with fever and a sore throat. For 6 weeks she was treated with methimazole. Laboratory examinations revealed agranulocytosis (total leukocyte count of 0.5 × 109 cells/L, compared to the normal range of 4 to 10 × 109 cells/L, with granulocytes at 0.2% and lymphocytes at 81.3%). The bone marrow aspirate also showed a markedly reduced number of mature granulocytes. In peripheral blood cultures Pseudomonas aeruginosa was isolated. A perianal and perineal inflammation became visible and worsened within hours, spreading to the right gluteal region involving the genital, suprapubic and bilateral inguinal regions. This case of Fournier gangrene required intensive medical care and multiple surgeries. Conclusion: Albeit a rare case, the history of this patient emphasizes the importance of awareness of the adverse effects ATDs can provoke and underlines the necessity for structured clinical management if they do occur. To our knowledge, this is the first report on synchronous antithyroid drug-induced agranulocytosis and Fournier gangrene. Abbreviations: ATDs antithyroid drugs; G-CSFs granulocyte colony-stimulating factors