Necrotizing dermatitis in patients receiving cancer chemotherapy.

Necrotizing dermatitis in patients being treated with cancer chemotherapeutic agents can be of several types. Microbial causes can include a variety of bacteria and fungi, the most common being Pseudomonas aeruginosa. Gangrene from occlusive causes is not uncommon among cancer patients with coexisting atheromatous, thromboembolic, or obliterative vascular disease. Toxic gangrene is most commonly caused by extravasation of intravenously administered cytotoxic antineoplastic drugs but has also been associated with the use of coumarin congeners and the bite of the brown recluse spider. Pyoderma gangrenosum is an idiopathic condition that has been reported in association with myeloproliferative disorders. Finally, necrosis can be caused by the neoplasm itself, when its growth is so great that blood vessels are compressed and ischemia of the surrounding tissue results.