Abstract Introduction Henoch-Schönlein Purpura (HSP), or IgA vasculitis, is an immune-mediated small-vessel vasculitis that typically affects children but can rarely occur in adults, often with more severe manifestations. Drug-induced HSP is an uncommon adverse reaction, particularly in association with antithyroid medications. Clinical Case We report the case of a 35-year-old male with recently diagnosed hyperthyroidism treated with methimazole who presented with a 5-day history of symmetric palpable purpura on the lower extremities and buttocks, abdominal pain, and arthralgia. Laboratory workup showed suppressed TSH and elevated free thyroxine, confirming ongoing thyrotoxicosis. Inflammatory markers were unremarkable, and no renal involvement was evident. A clinical diagnosis of HSP was made, supported by the absence of thrombocytopenia or coagulopathy. Methimazole, suspected as the causative agent, was discontinued, resulting in complete symptom resolution within 10 days. Conclusion This case highlights methimazole as a potential but rare trigger for HSP. Clinicians should maintain a high index of suspicion for vasculitis in patients presenting with purpura while on thionamide therapy. Prompt drug withdrawal and supportive care can lead to rapid recovery and prevent complications.
Adel Gassab Gassab Mohammed (Thu,) studied this question.