Sweet’s Syndrome: A Frequently Unrecognized Complication Following Acute Myeloid Leukemia (Aml) Induction Chemotherapy: A Case Report.

Sweet’s syndrome, also known as acute febrile neutrophilic dermatoses, is a distinct clinicopathologic entity of unknown etiology characterized by acute onset of fever, leukocytosis, and cutaneous plaques. It has been associated with a variety of disorders including infections, neoplasms, and autoimmune diseases. Paraneoplastic Sweet’s syndrome is most often associated with hematologic malignancies, including myelogenous leukemia and myelodysplastic syndrome (MDS), are most often associated. Although patients with neutrophilia are most likely to be diagnosed with Sweet’s syndrome, so, too, may patients who are neutropenic post-cytotoxic chemotherapy. Herein, we describe the clinical course of a 60-year-old Caucasian man with a history of high-risk MDS who, after progressing to AML and while neutropenic post-induction chemotherapy, was diagnosed with Sweet’s syndrome. The patient developed a warm, tender, indurated, erythematous lesion over his left anterior chest on day +6 of induction chemotherapy consisting of idarubicin and cytarabine. Despite broad spectrum antibiotics, the lesion darkened, formed blisters, and progressed rapidly to involve much of his left chest. On day +11, his WBC had fallen to 0.7×10⁹cells/l and the wound was surgically debrided due to concern that he had developed necrotizing fasciitis. Surgical samples showed significant dermal infiltration of neutrophils and severe necrosis of skin and subcutaneous tissue, but no pathologic organisms or leukemic cells. Empiric antibiotic coverage was broadened to include amphotericin B, voriconazole, and valganciclovir, but the patient failed to improve. On day +18, he began taking 60mg Prednisone daily and his lesions quickly improved. Although Sweet’s syndrome most often occurs in conjunction with neutrophilia, it may also occur in neutropenic patients who have received systemic chemotherapy. This association with neutropenia is more frequent than is generally appreciated; as many as 20–50% of patients with hematologic malignancies may be diagnosed with Sweet’s syndrome while recovering from therapy-associated neutropenia. Cancer-associated Sweet’s syndrome may be more severe than that seen in patients without malignancy. Lesions may progress from plaques and nodules to vesicular, bullous, and even ulcerative skin lesions, as was seen in our patient. Our case report serves as a reminder that Sweet’s syndrome may occur in the setting of neutropenia and, if diagnosis and treatment are delayed, can lead to a life-threatening complication. Early skin biopsy and histopathologic assessment followed by corticosteroids is essential for recognition and management of this entity.