Table 2.

Diagnostic criteria for classic and drug-induced Sweet’s syndrome^[65]

Classical Sweet’s syndrome
Major Criteria (both are mandatory) Abrupt onset of painful erythematous plaques or nodules. Histopathologic evidence of a dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis.
Minor Criteria Pyrexia: T>38°C. Association with an underlying hematologic or visceral malignancy, inflammatory disease, pregnancy, or preceded by an upper respiratory or gastrointestinal infection or vaccination. Excellent response to treatment with systemic corticosteroids or potassium iodide. Abnormal laboratory findings (3 of 4):                           ESR>20mm/hr / positive CRP / WBC>8000 /Neutrophilia > 70%.
Drug-induced
Abrupt onset of painful erythematous plaques or nodules. Histopathologic evidence of a dense neutrophilic infiltrate. Pyrexia: T>38°C. Temporal relationship between drug ingestion and clinical presentation, or temporally related recurrence after oral challenge. Temporally related resolution of lesions after drug withdrawal or treatment with systemic corticosteroids.

Diagnosis of classic Sweet’s syndrome is confirmed by 2 major criteria and two of the four minor criteria but for diagnosis of drug-induced Sweet’s syndrome all five criteria are mandatory.