Sweet's syndrome


  • Acute febrile neutrophilic dermatosis
  • Rare skin condition
  • Usually affects age 30-60, but can happen in any age group
  • Classic Sweet syndrome affects women > men
  • Unclear pathologenesis, but possibly factors include hypersensitivity reaction, cytokine dysregulation, or genetic susceptibility


  • Classical Sweet syndrome, usually secondary to:
  • Malignancy-associated Sweet syndrome
    • Hematologic (~85%), most commonly acute myeloid leukemia
    • Solid tumor (~15%), most commonly carcinoma of GU organs, breasts, GI tract
  • Drug-induced Sweet syndrome, most commonly granulocyte-colony stimulating factor (G-CSF)
    • Typically 2 weeks after drug exposure in patient without prior exposure
  • Fever and rash

Clinical Features

Sweet's Syndrome of index finger[1]
Sweet's syndrome with lesions distributed in a sporotrichoid pattern.
Targetoid papules and plaques in Sweet's syndrome
  • Cutaneous disease
    • Painful, edematous, and erythematous papules, plaques, or nodules
    • Often exhibit a mamillated surface with significant superficial dermal edema leading to pseudovesicular quality
    • Usually upper extremities > lower extremities, with asymmetrical distribution
  • Extracutaneous disease: neutrophilic infiltration of organ systems
  • Fever and leukocytosis

Differential Diagnosis



  • CBC
    • leukocytosis with neutrophilia
    • anemia (more common in malignancy or drug associated)
    • platelet abnormalities (more common in malignancy or drug associated)
  • Complete metabolic panel
  • Urinalysis
  • ESR
  • CRP


Major criteria

  • Abrupt onset painful erythematous plaques or nodules
  • Histopathological evidence of neutrophilic infiltrate without evidence of leukocyoclastic vasculitis

Minor criteria

  • Fever
  • Associated malignancy, IBD, pregnancy, preceding URI, preceding GI infection
  • Improvement with treatment with systemic steroids
  • Abnormal labs (3+ of following): ESR > 20, elevated CRP, leukocytosis, neutrophilic predominance


  • Systemic glucocorticoids - prednisone 0.5 - 1.0 mg/kg per day with taper after symptom improvement
  • Topical and intralesional corticosteroids - limited data, mostly used as adjunct, for mild disease (<5% BSA), or absence of systemic symptoms
  • Alternatives agents include colchicine, dapsone, potassium iodide if steroids contraindicated
  • Referral to dermatology for biopsy
  • Evaluation for malignancy (if clinically appropriate)
    • If other concerning symptoms and no other explanation for diagnosis


  • Usually outpatient with close dermatology follow up

See Also

External Links


  1. Cohen, P.R. Sweet's syndrome – a comprehensive review of an acute febrile neutrophilic dermatosis. Orphanet J Rare Dis 2, 34 (2007). https://doi.org/10.1186/1750-1172-2-34