Peripheral arthritis occurs in approximately 10%–20% of people with inflammatory bowel disease, either Crohn’s disease or ulcerative colitis. Some patients actually present with the inflammatory arthritis before the diagnosis of inflammatory bowel disease is recognized. The disease may begin at any age, but occurs most often in young adults, affecting males and females in equal distribution.
The pattern of the peripheral arthritis is variable. It commonly affects the lower extremity joints. Deformities are rare and the arthritis tends to be non-erosive. In ulcerative colitis the activity of the peripheral arthritis parallels the activity of the bowel inflammation.
Arthritis affecting the axial skeleton, or spine, called spondylarthropathy, occurs more commonly in men than women. It is not affected by the bowel inflammation. Also, there is an association with HLA-B27, although much lower than with ankylosing spondylitis.
The pathogenesis of inflammatory bowel disease and spondylarthropathy suggest both genetic and environmental factors. The genetic link includes, in addition to HLA-B27, a region on chromosome 16. The relationship between gastrointestinal flora and the inflammatory changes is also important. There is likely interplay between genetic, environmental, and immunological factors.
The extraarticular manifestations of the arthropathy of inflammatory bowel disease include skin lesions, clubbing, vasculitis, amyloidosis, osteoporosis and osteomalacia.
The treatment of the inflammatory arthritis encompasses treating the underlying bowel disease. Immunosuppressive and biologics have been used for the treatment of the inflammatory bowel disease and the arthritis.