Arthritic manifestations of inflammatory bowel disease.

Rheumatologic conditions associated with inflammatory bowel disease may be divided into four clinical categories. First, a unique form of peripheral arthritis occurs in 15-20% of patients with inflammatory bowel disease. The incidence is higher in Crohn's disease than in ulcerative colitis. This is a self-limited, nondeforming, seronegative arthritis that waxes and wanes with bowel flares. It characteristically involves knees and ankles. Persistent erosive monoarthritis is described. Second, spondylitis clinically and radiographically indistinguishable from idiopathic ankylosing spondylitis occurs in 3-6% of patients with inflammatory bowel disease. HLA-B27 positivity occurs in 53-75% of cases, fewer than in idiopathic spondylitis. Third, a bilateral, symmetrical sacroiliitis is seen in 4-18% of patients. This may not progress to clinical spondylitis. The fourth category encompasses rheumatologic complications of inflammatory bowel disease. These include granulomas of bones and joints, granulomatous vasculitis, clubbing, periostitis, amyloidosis, osteoporosis, osteomalacia, septic arthritis, and complications of corticosteroid therapy.