[Extraintestinal manifestations of Crohn's disease].

Specific extraintestinal manifestations of Crohn's disease are rare except the involvement of the anal region. Only few case reports have been published concerning Crohn's disease of the lips, the mouth, the hypopharynx, the skin, urogenital tract, bone and joints. However, Crohn's disease of the anal region is of great significance. About 30 % of the patients develope fistulae, fissures, abscesses and perianal edema. The anal disease is often a first important and often missed sign of intestinal M. Crohn. Biopsy and histological investigations of the diseased tissue reveals typical histological changes in up to 60-70 % of the patients with anal disease.