Infliximab-Induced Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis Syndrome

This case report describes a 21-year-old woman with Crohn's colitis and alopecia areata who developed infliximab-induced SAPHO syndrome, characterized by synovitis, acne, pustulosis, hyperostosis, and osteitis. Her symptoms, including progressive hair loss, acne, and a generalized rash, emerged after increasing her infliximab dosage. Despite trials with risankizumab and cyclosporine, her condition improved rapidly with Spesolimab and methotrexate. This case highlights the complexity of SAPHO syndrome as a potential adverse effect of infliximab, suggesting it may involve dual autoimmune pathophysiologies. The rarity of SAPHO syndrome and its paradoxical response to infliximab complicate treatment guidelines.