A case of generalized cat scratch disease in a patient with ulcerative colitis on immunosuppressive therapy.

Cat scratch disease (CSD) is a zoonotic disease transmitted to humans, usually via scratches or bites. Bartonella henselae is the primary causative agent. It causes a mild, self-limiting disease. In immunocompromised patients, the course of the infection can be more serious because of the suppressed antibacterial response, causing a life-threatening disease. A 54-year-old male patient presented with ulcerative colitis. Five days after receiving the first dose of infliximab 400 mg intravenously and 0.5 mg/kg methylprednisolone, he presented with enlarged axillary lymph nodes and colliquation of the intraabdominal lymph node with intrahepatic colliquating areas caused by B. henselae after cat bites. Long-term treatment with multiple antibiotics and prednisolone resulted in clinical improvement and regression of the liver and intra-abdominal lymph nodes. After further treatment for ulcerative colitis, we assessed the possibility of reintroducing immunosuppressive therapy. Adalimumab was introduced after consulting an infectious disease specialist. At the follow-up visit, the patient was in remission of ulcerative colitis and without signs of reactivation of bartonellosis. Diseases such as CSD with a benign clinical appearance and prognosis can develop a severe and life-threatening course in immunocompromised patients. This requires a complex understanding of the immune processes in such patients, and the reintroduction of immunosuppressive therapy after successful treatment of CSD probably does not increase the risk of reactivation.