Hidradenitis suppurativa and inflammatory bowel disease: are they associated? Results of a pilot study.

Background The co-occurrence of hidradenitis suppurativa (HS) and Crohn disease (CD) published in a few case reports resulted in the wide acceptance of an association between these two diseases. However, the combined prevalence of these diseases is currently unknown; furthermore, it is unknown whether this co-occurrence also applies for ulcerative colitis (UC). Objectives To estimate the prevalence of HS in patients with inflammatory bowel disease (IBD) living in the Southwest of the Netherlands. Methods During an IBD patient information meeting, randomly, 158 patients with IBD were interviewed about recurrent painful boils in the axillae and/or groin and were shown illustrative clinical pictures of the appearance of HS. Results Of the 158 patients interviewed, 102 (65%) had CD and 56 (35%) had UC. Twenty-five people (16%) responded that they had had or still experienced painful boils in the axillae and/or groin, of whom 17 were patients with CD (17%) and eight had UC (14%). Conclusions This pilot study shows for the first time that HS occurs in patients with CD or UC. More prospective studies are warranted to establish the association between HS and IBD and its underlying pathogenesis.