Appendiceal orifice inflammation as a skip lesion in ulcerative colitis: an analysis in relation to medical therapy and disease extent

Background: Although several reports have claimed that the appendix can be involved as a skip lesion in ulcerative colitis, they do not exclude the po ssibility that this skip lesion occurs as a result of medical therapy. Also , little is known about the relation between the presence of appendiceal or ifice inflammation and the extent of the disease. Methods: The presence of appendiceal orifice inflammation was prospectively assessed both endoscopically and histologically in 94 patients with active ulcerative colitis, the extent of whose disease had not been beyond the he patic flexure. To evaluate the effect of prior medical therapy on the preva lence of appendiceal orifice inflammation, all cases were divided into two groups. Group A consisted of 66 patients who had been treated before inclus ion; group B was composed of 28 patients newly diagnosed at inclusion. Results: Appendiceal orifice inflammation was diagnosed in 24 (26%) of 94 p atients with active subtotal ulcerative colitis, with no statistical differ ence observed between group A (23%) and group B (32%). In all 94 patients, the frequency of appendiceal orifice inflammation decreased significantly a s the extent of disease increased, i.e., 37% in proctitis (n = 49), 17% in left-sided colitis (n = 36), and 0% in extensive colitis (n = 9) (p < 0.05) . Conclusions: Appendiceal orifice inflammation as a skip lesion of ulcerativ e colitis is not rare, is more frequently observed in patients with less ex tensive disease, and is not the result of patchy improvement due to medical therapy.