Background and aims: Extra-intestinal manifestations are well recognized in inflammatory bowel disease (IBD). To what extent the commonly recognized extra-intestinal manifestations seen in IBD patients are attributable to IBD is, however, not clear due to the limited number of controlled studies published.
Methods: We have conducted a study of these manifestations using electronic primary care records. We have identified extra-intestinal manifestations in IBD and non-IBD patients and derived odds ratios (ORs) using conditional logistic regression.
Results: A total of 56,097 IBD patients (32.5 % Crohn's disease, 48.3 % ulcerative colitis (UC) and 19.2 % not classified) were matched to 280,382 non-IBD controls. We found records of pyoderma gangrenosum (OR = 29.24), erythema nodosum (OR = 5.95), primary sclerosing cholangitis (OR = 188.25), uveitis (OR = 2.81), ankylosing spondylitis (OR = 7.07), sacroiliitis (OR = 2.79) and non-rheumatoid inflammatory arthritides (OR = 2.66) to be associated with IBD. One or more of these was recorded in 8.1 % of IBD patients and 2.3 % of controls. Non-specific arthritides were present in many more patients, affecting 30 % of IBD patients and 23.8 % of controls overall. We also found weaker associations with a number of conditions not generally considered to be extra-intestinal manifestations including psoriasis, ischemic heart disease, multiple sclerosis and hay fever.
Conclusion: Although "classical" extra-intestinal manifestations are strongly associated with IBD, most IBD patients remain unaffected. Arthropathies, perceived to be the commonest extra-intestinal manifestation, are not strongly associated with IBD, and the proportion of arthropathies attributable to IBD is likely to be small.
Keywords: Arthritis; Epidemiology; Inflammatory bowel diseases; Iritis; Pyoderma.