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Sweet’s syndrome (SS), or acute febrile neutrophilic dermatosis is a skin disease characterized by the sudden onset of fever, leukocytosis, acute, tender, red papules & plaques and a papillary dermal infiltrate of neutrophils.
History
The syndrome was first described in 1964 by Robert Douglas Sweet. It was also known as Gomm-Button disease in honour of the first two patients Sweet diagnosed with the condition.
Aetiology
- Classical/idiopathic SS
- Malignancy-associated SS (paraneoplastic syndrome)
- Drug-induced SS
Clinical features
- Acute, tender, erythematous plaques, nodes, pseudovesicles and, occasionally, blisters
- Pattern: Annular/arciform
- Location: Head, neck, legs, and arms, particularly the back of the hands and fingers. The trunk is rarely involved.


Associated features:
- Fever (50% cases)
- Arthralgia/arthritis (62% cases)
- Eye involvement: conjunctivitis/iridocyclitis (38% cases)
- Oral aphthae (13% cases)
Diagnosis
Blood panel:
- Moderate neutrophilia (< 50% cases)
- ↑ ESR (> 30 mm/h) (90% cases)
- Slight ↑ in alkaline phosphatase (83% cases)
Histopathology:
- Papillary and mid-dermal mixed infiltrate of polymorphonuclear leukocytes with nuclear fragmentation and histiocytic cells.
- Infiltrate is predominantly perivascular with endothelial-cell swelling in some vessels, but vasculitic changes (blood clots; deposition of fibrin, complement, or immunoglobulins within the vessel walls; RBC extravasation; inflammatory infiltration of vascular walls) are absent in early lesions.

Differential diagnosis:
- Pyoderma gangrenosum
- Infection
- Erythema multiforme
- Adverse drug reactions
- Urticaria
Management
- Systemic corticosteroids (prednisone) (GOLD STANDARD)
- Tapered within 2-6 weeks to 0
- Indomethacin (2nd-line treatment, or corticosteroid contraindication)
- 150 mg/day (1st week)
- 100 mg/day (2 weeks)
- Alternative drugs:
- Dapsone, doxycycline, clofazimine, and cyclosporine