Infliximab-Responsive Severe Ulcerative Colitis With Pyoderma Gangrenosum After IL-6 and IGF-1 Blockade.

Interleukin-6 (IL-6) and insulin-like growth factor-1 (IGF-1) are involved in immune regulation and tissue repair, but their combined effects on gastrointestinal mucosa remain unclear. We report a case of new-onset ulcerative colitis with pyoderma gangrenosum after sequential IL-6 and IGF-1 receptor inhibition. The patient developed severe ulcerative colitis and pyoderma gangrenosum refractory to corticosteroids but showed rapid improvement after infliximab therapy, with endoscopic evidence of mucosal improvement. This case highlights a potential role for tumor necrosis factor-α (TNF-α) blockade in reversing severe immune dysregulation induced by IL-6 and IGF-1 inhibition.