Multifocal Pyoderma Gangrenosum with an Underlying Hemophagocytic Lymphohistiocytosis: Case Report and the Review of the Literature.

Pyoderma gangrenosum (PG) is an uncommon, serious, ulcerating skin disease of uncertain etiology. It manifests as a noninfectious, progressive necrosis of the skin characterized by sterile neutrophilic infiltrates. It seems to be a disorder of the immune system.