A 39-year-old woman presents with lesions on her legs that first appeared 3 weeks earlier. In the days that followed, the rash spread to her arms and back. She visited her primary care practitioner (PCP), who referred her to the dermatology clinic. The patient reports that the lesions are mildly tender and itchy. She experienced a 2-day episode of low-grade fever, chills, and malaise before the onset of the lesions on her legs. She has no significant medical history and denies having had a similar condition. Laboratory testing performed by her PCP showed no abnormalities.
Submit your diagnosis to see full explanation.
Biopsy was performed and revealed Sweet syndrome. Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is a rare disorder that presents as scattered, tender, erythematous plaques or nodules accompanied by fever and neutrophilia.1 The condition most commonly affects women in the third to fifth decades of life and may present in 3 clinical settings: classic (idiopathic), malignancy associated, and drug induced.1,2 Additional associations include infection, inflammatory bowel disease, autoimmune connective tissue disease, pregnancy, and myelodysplastic syndromes.2,3 Sweet syndrome may be a cutaneous sign of an undiagnosed malignancy or a harbinger of cancer recurrence.3
Diagnosis of Sweet syndrome is based on the presence of defined parameters: abrupt onset of painful erythematous plaques or nodules and histopathologic findings of dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis.4 Minor criteria include fever, upper respiratory or gastrointestinal infection, vaccination, neoplasia, inflammatory disorders, pregnancy, and positive response to treatment with corticosteroids or potassium iodide.4
First-line therapy for Sweet syndrome is systemic glucocorticosteroid administration. Additional effective treatments include, but are not limited to, topical or intralesional corticosteroids, potassium iodide, colchicine, dapsone, and biologic agents.4,5 If onset is related to the administration of a drug or an underlying disease or malignancy, treatment and removal of the causative factor should be emphasized.3,4 Lesions will typically resolve with or without treatment; however, one-third of patients will experience recurrence.1,3
Nelson Maniscalco, DPM, is a joint podiatry/dermatology fellow under the aegis of St. Luke’s Medical Center in Allentown, Pennsylvania, and the DermDox Center for Dermatology. Stephen Schleicher, MD, is director of the DermDox Center for Dermatology, associate professor of medicine at Commonwealth Medical College, and clinical instructor of dermatology at Arcadia University and Kings College.
1. Cohen PR. Sweet’s syndrome – a comprehensive review of an acute febrile neutrophilic dermatosis. Orphanet J Rare Dis. 2007;2:34.
2. Kulasekararaj AG, Kordasti S, Basu T, et al. Chronic relapsing remitting Sweet syndrome – a harbinger of myelodysplastic syndrome. Br J Haematol. 2015;170(5):649-656.
3. Raza S, Kirkland RS, Patel AA, Shortridge JR, Freter C. Insight into Sweet’s syndrome and associated-malignancy: a review of the current literature. Int J Oncol. 2013;42(5):1516-1522.
4. Heath MS, Ortega-Loayza AG. Insights into the pathogenesis of Sweet’s syndrome. Front Immunol. 2019;10:414.
5. Mollaeian A, Roudsari H, Talebi E. Sweet’s syndrome: A classical presentation of a rare disease. J Investig Med High Impact Case Rep. 2019;7:2324709619895164.