Coexistence of Relapsing Polychondritis and Crohn's Disease: Clinical Insights from a Rare Case.

Relapsing polychondritis (RP) is a rare immune-mediated inflammatory disorder characterized by recurrent inflammation of cartilaginous structures. Although RP frequently coexists with other autoimmune disorders, its association with inflammatory bowel disease (IBD), particularly Crohn's disease, has been rarely described. We report the case of a 53-year-old man who presented with bilateral auricular inflammation sparing the earlobes and was diagnosed with RP based on clinical and histopathological findings. During treatment with systemic corticosteroids and methotrexate, he developed severe abdominal pain accompanied by inflammatory arthritis. These symptoms were initially considered related to treatment; however, subsequent endoscopic and histologic evaluation revealed Crohn's disease involving the terminal ileum. Therapeutic adjustment, including discontinuation of nonsteroidal anti-inflammatory drugs and optimization of immunosuppressive therapy, resulted in resolution of both gastrointestinal and musculoskeletal symptoms. This case emphasizes the importance of considering concomitant IBD in patients with RP who develop unexplained gastrointestinal manifestations. Recognizing this rare coexistence may facilitate earlier diagnosis and more appropriate therapeutic decision-making in patients with multisystem inflammatory disease.