[All-trans retinoic acid-induced erythema nodosum in acute promyelocytic leukemia].

A 24-year-old woman with acute promyelocytic leukemia was treated with all-trans retinoic acid (ATRA) as a remission induction therapy. After pneumonia in the neutropenic period was successfully treated with antibiotic treatment, there was recurrence of high fever alone, followed by the appearance of erythema nodosum with pain in her upper limbs on day 25 of ATRA therapy. Skin biopsy neither revealed infiltration of leukemic cells nor suggested Sweet's syndrome. We considered the eruptions to be associated with ATRA, and prednisolone (30 mg/day for 5 days) was administered. Although the administration of ATRA was continued until complete remission of the leukemia, the erythema nodosum rapidly disappeared following short-term steroid therapy and no recurrence was observed. ATRA-induced erythema nodosum is rare, however it should be recognized as a possible adverse effect in ATRA therapy.