Severe psoriasis preceding diagnosis of large bowel Crohn's disease for 15years

Dear Sir,Psoriasis is a chronic, relapsing, autoimmune disease that represents a relatively rare extraintestinal manifestation especially in patients with inflammatory bowel disease.1,2 In Germany the relative risk of developing psoriasis in a patient with Crohn's disease (CD) has been estimated to be 2.1.3 The underlying relationship between these two disorders is largely unknown although it seems to comprise genetic data (involvement of shared predisposing loci or genes), immunological data (inflammation mechanisms such as activation pathway of Th17 lymphocytes), and environmental co-factors (smoking, possibly certain …