One-fifth of patients with IBD have arthritis, which complicates Crohn disease somewhat more frequently than it does ulcerative colitis. In both diseases, two distinct forms of arthritis occur. The first is peripheral arthritis—usually a nondeforming asymmetric oligoarthritis of large joints—in which the activity of the joint disease parallels that of the bowel disease. The arthritis usually begins months to years after the bowel disease, but occasionally the joint symptoms develop earlier and may be prominent enough to cause the patient to overlook intestinal symptoms. The second form of arthritis is a spondylitis that is indistinguishable by symptoms or radiographs from ankylosing spondylitis and follows a course independent of the bowel disease. About 50% of these patients are HLA-B27 positive.
Controlling the intestinal inflammation usually eliminates the peripheral arthritis. NSAIDs can be effective when the arthritis is mild but must be used cautiously since they can exacerbate IBD. TNF inhibitors are useful therapies because they are effective both for the bowel and joints.
Whipple disease should be considered in the differential diagnosis for a patient with GI and joint symptoms. Two-thirds of patients with Whipple disease experience arthralgia or arthritis, most often an episodic, large-joint polyarthritis. The arthritis usually precedes the GI manifestations by years and often resolves as the diarrhea develops.
et al. Prevalence, predictors, and disease activity of sacroiliitis among patients with Crohn’s disease. Inflamm Bowel Dis. 2021;27:809.