Erythema nodosum after azacitidine in a patient with acute myeloid leukemia.

Given the onset of lesions one week after the initiation of azacitidine and 5 weeks after the initiation of sorafenib, azacitidine was considered the more likely culprit. Only 2 cases of EN-like eruption after azacitidine and 1 case after sorafenib have been reported. Although fungal infections and leukemia cutis are the top differentials considered for skin nodules in a patient with AML, EN should be considered as an alternative diagnosis. Correct diagnosis is critical because it will guide treatment.