[Cutaneous symptoms of ulcero-haemorragic rectocolitis and of Crohn's disease (author's transl)].

The association between ulcerative colitis, Crohn's disease and various abnormalities of the skin is reviewed. Erythema nodosum and pyoderma gangrenosum are the most specific external manifestations and thereby the ones of greatest diagnostic value. Erythema multiforme is probably a manifestation of drug hypersensitivity. Many other dermatosis have been observed in association with these gastrointestinal disorders. However, these associations are not statistically significant. A specific "aphtous colitis" may be observed in the course of Behçet's disease.