[Skin manifestations of diseases of the gastrointestinal tract].

Diseases of the gut frequently show skin symptoms. These can give first and important clues in regard to diagnosis. In general the etiology can be divided into genetic disorders, chronic inflammation, drug reaction, infectious diseases or related to malignancy. In genetic disorders increasing knowledge about the involved genes is available, allowing prenatal diagnosis and screening of clinically not affected family members. Especially in cancer prone syndromes early diagnosis and preventive treatment is crucial. Inflammatory bowel diseases show a high prevalence, therefore necessitating the knowledge of skin complications such as pyoderma gangrenosum, Sweet syndrome and erythema nodosum. Gastrointestinal malignancies may metastasize into the skin or may produce typical paraneoplastic changes.