Cytarabine (Cytosar)

Cytosine arabinoside-induced vasculitis

Dermatologic side effects of cytosine arabinoside (ara-C) are rare and most commonly occur after high-dose (more than 100 to 200 mg/m2 per day) therapy has been administered for several days. Although vascular reactions after combination chemotherapeutic regimens with ara-C have been anecdotally described, they have not been previously reported after single-agent chemotherapy with ara-C. Herein we describe two patients with acute nonlymphoblastic leukemia in whom cutaneous small vessel necrotizing vasculitis developed after high-dose single-agent chemotherapy with ara-C. Cutaneous lesions developed 3 to 5 days after initiation of therapy and resolved spontaneously within a week after the chemotherapeutic regimen was completed. No evidence of systemic vasculitis was present in either patient. Prior experimental data have demonstrated a direct toxic effect of ara-C on endothelial cells, and this outcome may represent the underlying mechanism of vascular injury.

Neutrophilic eccrine hidradenitis: a distinctive rash associated with cytarabine therapy and acute leukemia

Neutrophilic eccrine hidradenitis (NEH) is a recently described neutrophilic dermatosis associated with acute myelogenous leukemia (AML) and chemotherapy. This disorder is a distinct clinicopathologic entity separate from leukemid reactions and other neutrophilic dermatoses. We describe two cases in which plaques or nodules developed in the second week after initiation of induction chemotherapy for AML. The lesions regressed in 1 week and recurred in one case when induction chemotherapy was given a second time. Histologically, the findings were similar in each case. Neutrophils palisaded about and infiltrated the eccrine coil in which necrosis of secretory epithelium was present. Focal mucinous degeneration of the eccrine adipose tissue cuff was the only other significant alteration. No vasculitis was observed. Cultures and histologic preparations for pathogenic organisms were negative. Cytarabine was the chemotherapeutic agent used in all three cases. NEH most likely represents either an unusual response caused by cytarabine or a manifestation of AML. Recognition of NEH is important in order to exclude other neutrophilic dermatoses associated with AML, such as sepsis and leukemia cutis, which may appear clinically similar.