Psoriasis without neutrophils

Histologic studies suggest that polymorphonuclear leukocytes (polys) may initiate, enable, and/or enhance the development of psoriasis. A man with long-standing psoriasis developed acute myelogenous leukemia. His psoriasis disappeared after treatment with daunorubicin and cytosine arabinoside. Smears of his peripheral blood showed essentially zero polys from day 10 to day 22 after start of chemotherapy. His psoriasis began to reappear on day 14, became prominent by day 16, and persisted. Polys may not be requisite for the development and maintenance of psoriasis.