[Pyoderma gangrenosum (dermatitis ulcerosa)]

Even though pyoderma gangrenosum (dermatitis ulcerosa) is still considered to be a polyetiological syndrome with uncertain pathogenesis, immunological processes are attributed to it. It serves as an indicator of an underlying internal disease. A more than incidental occurrence is found of inflammatory intestinal diseases such as colitis ulcerosa, inflammatory joint disorders, among hematological diseases predominantly myeloic leukemia, paraproteinemia with and without plasmocytoma as well as inflammatory vascular processes. A variety of other simultaneous diseases have to be considered as isolated case reports; it remains for future investigations to decide if these will be classified among the merely coincidental diseases or as various manifestations of a common immunological process.