Successful Immunosuppressive Therapy for Aseptic Abscess Syndrome Presenting with a Fever of Unknown Origin

Aseptic abscess syndrome (AAS) is a rare autoinflammatory disease characterized by sterile abscesses in various organs, and it is often associated with inflammatory bowel disease (IBD). We report the case of a 70-year-old woman with recurrent fever, multiple colonic aphthae, and painful limb nodules. A computed tomography (CT) scan revealed multiple splenic lesions, and aspiration revealed white purulent fluid. Despite the diagnosis of multiple splenic abscesses, antibiotic therapy was ineffective, and cultures from the blood and splenic aspirate were negative. AAS was suspected and immunosuppressive therapy with corticosteroids led to rapid symptom resolution. The patient remained relapse-free after administering azathioprine and colchicine maintenance therapy.