Last update:
07-Sep-2012

Skin manifestations are frequent in patients with inflammatory bowel disease (IBD); approximately 10% of patients are initially referred because of a skin condition related to IBD, while 20% of patients develop a dermatological problem requiring specific diagnosis and treatment during the course of the disease. From the practical point of view, dermatological manifestations may be diagnosed at any time during the IBD disease course and they can be classified in many ways: "disease-specific" or "non-specific", in relation to the baseline IBD diagnosis, ulcerative colitis (UC) or Crohn's disease (CD), or in relation to the initial consultant physician, who may be either a gastroenterologist or a dermatologist, especially in cases where the skin manifestations precede the symptoms of bowel disease. The detailed pathogenetic mechanisms of the disease-specific dermatological manifestations in IBD have not yet been elucidated. It is probable that a cross reaction in immunological-related epitopes of bowel epithelium and skin occurs in some of the patients. The non disease specific dermatological manifestations in IBD represent a relatively rare group of non-specific, hyper-allergic immunologically derived conditions. Increased prevalence of skin problems has been noted with all disease manifestations across the whole spectrum of IBD, but with different frequencies for UC and CD. The skin manifestations commonly seen in IBD are: erythema nodosum, pyoderma gangrenosum, Sweet's syndrome, relapsing apthous stomatitis, colostomy/ileostomy dermatitis and neutrophilic dermatitis. In addition, several forms of skin vasculitis may occur, including small vessel vasculitis and dermatic polyarteritis nodosa. The pathognomonic muco-cutaneous manifestations of UC are dermatitis bullosa and pyostomatitis vegetans. The pathognomonic manifestations of CD are fistulas and perianal fissures, and the so-called "metastatic" Crohn's disease in cases where the skin disease is clearly separated from healthy normal tissue, oro-facial CD and Melkersson-Rosenthal granulomatous cheilitis. There are also some specific associations between IBD and idiopathic inflammatory skin diseases such as between CD and psoriasis and hidradenitis suppurativa and between UC and atopic eczema. Skin manifestations may be related to malnutrition and to enteral and parenteral nutrition. Nail and hair abnormalities are also a feature of IBD.

Key words: Crohn's disease, Dermatological, Inflammatory bowel disease, Skin, Ulcerative colitis.