Crohn's Disease with Cutaneous Polyarteritis Nodosa in a Child: A Case Report.

A 10-year-old boy presented with a 1-day history of multiple painful erythematous skin lesions on his upper and lower extremities. He was admitted to the Department of Pediatrics with persistent right lower abdominal pain and diarrhea. Punch biopsy of a skin lesion on his lower leg showed necrotizing granulomatous vasculitis with septal panniculitis consistent with polyarteritis nodosa, and our differential diagnosis included cutaneous manifestations of Croh's disease. Abdominal ultrasonography revealed distended colonic loops suggestive of inflammatory bowel disease. Upper and lower gastrointestinal endoscopy revealed lesions involving the duodenum, cecum, colon, and rectum. He developed multiple perianal fistulas during hospitalization. Additional laboratory tests revealed positive results for anti-saccharomyces cerevisiae and antinuclear antibodies. Based on his clinical presentation and laboratory findings, he was diagnosed with Crohn's disease associated with cutaneous polyarteritis nodosa. We report a rare case of a child who presented with cutaneous polyarteritis nodosa as an extraintestinal manifestation of Crohn's disease.