Significance of erythema nodosum and pyoderma gangrenosum in inflammatory bowel diseases: a cohort study of 2402 patients.

Erythema nodosum and pyoderma gangrenosum are the most common cutaneous manifestations in inflammatory bowel diseases (IBD). We conducted the current study to assess the cumulative prevalence of erythema nodosum and pyoderma gangrenosum in patients with IBD and to appraise their association with demographic, clinical, and prognostic factors related to IBD. Between 2000 and 2005, data for all patients with IBD at our gastroenterology department were prospectively and systematically collected using a standardized protocol. Among 2402 patients (1521 diagnosed with Crohn disease [63.3%] and 744 with ulcerative colitis [31.0%]), 140 (5.8%) had at least 1 skin manifestation. The most frequent dermatologic symptoms were erythema nodosum (4.0%) and pyoderma gangrenosum (0.75%). In multivariate analyses, erythema nodosum was significantly and independently associated with a diagnosis of Crohn disease (p < 0.001), female sex (p < 0.001), eye and joint involvement (p < 0.001), and pyoderma gangrenosum (p < 0.0001). Among patients with Crohn disease, erythema nodosum was associated with isolated colonic involvement (p = 0.0001). Pyoderma gangrenosum was significantly and independently associated with black African origin (p = 0.003), familial history of ulcerative colitis (p = 0.0005), uninterrupted pancolitis as the initial location of IBD (p = 0.03), permanent stoma (p = 0.002), eye involvement (p = 0.001), and erythema nodosum (p < 0.0001). It is noteworthy that the association between pyoderma gangrenosum and permanent stoma persisted after exclusion of patients with peristomal pyoderma gangrenosum (p = 0.07). In conclusion, neither erythema nodosum nor pyoderma gangrenosum was significantly associated with the severity criteria in IBD; however, their occurrence may reflect a peculiar phenotype among affected patients.