A brief account of the pathology and pathogenesis of the cutaneous manifestations of Crohns disease

Inflammatory Bowel Disease (IBD) is a lifelong condition, which may occur in patients of any age. Prior to confirming a diagnosis of IBD, clinicians may face unusual non gastrointestinal symptoms. The extra intestinal manifestations of Crohn's disease (CD) may develop prior to signs of gastrointestinal involvement. Many of these extraintestinal clinical signs overlap with those seen in patients with Ulcerative Colitis (UC) making the diagnosis of CD more difficult. Apthous ulceration of the buccal mucosa, lips or tongue for example should alert the clinician to consider the presence of intestinal involvement. Skin manifestations such as Erythema Nodosum, Pyoderma gangrenosum occur more commonly in CD than in UC1. The aim of this article is to review the most frequent and important skin manifestations of CD including the primary cutaneous manifestations and those manifestations which are treatment related.