Abstract

Sweet’s syndrome, also known as acute febrile neutrophilic dermatosis, is characterized by fever, tender erythematous skin plaques, and a sterile neutrophilic infiltrate. There are multiple potential underlying etiologies, including paraneoplastic and drug-induced causes. We present a case of a 76-year-old gentleman with chronic myelomonocytic leukemia transformed into acute myeloid leukemia (AML) who experienced recurrent episodes of localized tender skin eruptions. Most recently, he developed a painful erythematous plaque on his abdomen at his azacitidine injection site 1 day following administration. The lesion improved rapidly after initiation of prednisone, and biopsy revealed sterile suppurative dermatitis with occasional eosinophils. These histological findings, as well as the distribution and temporal relationship with the patient’s azacitidine injections, are most consistent with azacitidine-induced Sweet’s syndrome. While paraneoplastic Sweet’s syndrome has been frequently observed in AML, there have only been a handful of cases documenting azacitadine-induced Sweet’s syndrome. Clinicians should be aware that Sweet’s syndrome in AML patients may not always represent a paraneoplastic process, but can also be azacitidine-induced.