Atypical Immunoglobulin A Vasculitis in a Pediatric Patient With Ulcerative Colitis.

Rates of pediatric inflammatory bowel disease and biologic therapy use continue to rise. Consequently, specialists and generalists should recognize potential complications and side effects. We report the unique case of an adolescent with ulcerative colitis (UC) on vedolizumab presenting with severe abdominal pain, hematochezia, and subsequent purpura. After extensive investigation and a complex clinical course, diagnosis of atypical immunoglobulin A vasculitis was made. This is the first pediatric case of vasculitis in a patient with UC on vedolizumab and only the second reported case overall in UC. This case illustrates the emerging diagnostic challenge of distinguishing inflammatory bowel disease treatment complications from other common pediatric conditions.