Sweet syndrome

Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is a rare inflammatory skin condition characterized by the sudden onset of painful, red or violaceous papules, plaques, or nodules on the skin, accompanied by fever and an elevated white blood cell count (particularly neutrophils). The condition was first described by Dr. Robert Douglas Sweet in 1964. Skin lesions most commonly appear on the face, neck, upper extremities, and trunk. Histologically, the hallmark finding is a dense infiltration of mature neutrophils in the dermis without evidence of infection. Sweet syndrome affects multiple body systems beyond the skin. While cutaneous involvement is the primary manifestation, extracutaneous involvement can occur in the eyes (conjunctivitis, episcleritis), joints (arthralgia, arthritis), lungs, liver, kidneys, and central nervous system. The condition is classified into three subtypes: classical (or idiopathic) Sweet syndrome, malignancy-associated Sweet syndrome, and drug-induced Sweet syndrome. Classical Sweet syndrome predominantly affects women aged 30 to 60 years and may be preceded by upper respiratory or gastrointestinal infections. Malignancy-associated Sweet syndrome occurs in approximately 20% of cases and is most commonly linked to hematologic malignancies, particularly acute myeloid leukemia. Drug-induced cases have been associated with granulocyte colony-stimulating factor (G-CSF) and certain other medications. The diagnosis is based on a combination of clinical features, laboratory findings (elevated erythrocyte sedimentation rate, neutrophilia, elevated C-reactive protein), and histopathological confirmation from skin biopsy. Treatment typically involves systemic corticosteroids, which produce a rapid and dramatic response. First-line therapy is usually oral prednisone, with most patients experiencing significant improvement within days. For patients who cannot tolerate corticosteroids or who have recurrent disease, alternative treatments include potassium iodide, colchicine, and dapsone. Recurrences occur in approximately one-third of patients with classical Sweet syndrome. When associated with an underlying malignancy, treatment of the underlying condition is essential for disease control.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Sweet syndrome