Granulomatous Microscopic Colitis Due to Allopurinol

This case report described a 77-year-old male with a rare form of microscopic colitis characterized by granulomatous inflammation, potentially linked to long-term allopurinol use. Despite normal endoscopic findings, colonic biopsies revealed significant inflammation, lymphocyte presence, and epithelioid granulomas. The patient was treated with budesonide, leading to almost complete symptom resolution within a month. The presence of granulomas, unusual in microscopic colitis, suggested a possible drug reaction, with allopurinol being a suspected cause. However, due to the patient's positive response to budesonide, allopurinol was not discontinued.