[Pyoderma gangraenosum with special reference to immunologic and hematologic parameters].

Clinically, the diagnosis "pyoderma gangraenosum" can easily be made on the basis of typical skin features. It has been agreed, so far, that numerous immune deficiencies may play a key role in the pathogenesis of this disease. On reviewing the recent case reports, we observe a change regarding the associated diseases in more than 50%: Whereas earlier reports refer to ulcerative colitis as the most frequent concomitant disease, we now find increasing evidence of hematologic problems in association with pyoderm gangraenosum.