Selected rheumatologic and dermatologic manifestations of inflammatory bowel disease.

This review focuses on the behavior and pathogenesis of selected dermatologic and rheumatologic manifestations of inflammatory bowel disease. Erythema nodosum, the most common skin lesion, correlates with activity of the bowel disease but not with its duration or extent. Resolution occurs with therapy of inflammatory bowel disease. Pyoderma gangrenosum, the most severe skin lesion, bears little relationship to the activity or extent of the colitis. Therapy is usually supportive, but dapsone and steroids appear promising. Immune and vasculitic mechanisms have been postulated for both skin lesions. Peripheral arthritis usually has its onset with or after the development of colitic symptoms. It worsens with exacerbation of bowel inflammation and responds to treatment of the bowel disease. Immune mechanisms are likely. Spondyloarthropathy usually occurs before the onset of overt intestinal disease. Its course is unrelated to the bowel inflammation, it does not respond to treatment of bowel disease, and it is associated with HLA B27.