From the Guidelines
Systemic corticosteroids are the most effective treatment for Sweet syndrome, particularly in patients with active disease and colonic involvement. Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is a rare inflammatory skin condition characterized by tender, red inflammatory nodules or papules, usually affecting the upper limbs, face or neck 1. The condition is part of the group of acute neutrophilic dermatoses that includes pyoderma gangrenosum, but can be distinguished by its appearance, distribution, and histological features.
Key Characteristics
- Strong predilection for women and patients with colonic involvement and other extraintestinal manifestations
- Rash is mostly associated with active disease
- Systemic corticosteroids have been reported to be effective in treating Sweet syndrome 1
Treatment Options
- Systemic corticosteroids, such as prednisone, are the primary treatment for Sweet syndrome
- Alternative treatments, such as colchicine, dapsone, or potassium iodide, may be used for patients who cannot tolerate or do not respond to corticosteroids
- Topical or intralesional corticosteroids may be used for localized disease It is essential to identify and treat any underlying cause of Sweet syndrome, such as infections, inflammatory diseases, or medication reactions, for complete resolution 1.
From the Research
Definition and Characteristics of Sweet Syndrome
- Sweet syndrome is a rare inflammatory disease characterized by the sudden appearance of tender erythematous skin lesions, often accompanied by pyrexia and elevated neutrophil count 2.
- It is also known as acute febrile neutrophilic dermatosis, and is characterized by a constellation of clinical symptoms, physical features, and pathologic findings which include fever, neutrophilia, tender erythematous skin lesions, and a diffuse infiltrate consisting predominantly of mature neutrophils that are typically located in the upper dermis 3.
Classification of Sweet Syndrome
- Sweet syndrome can be classified into three types: classical (or idiopathic) Sweet syndrome, malignancy-associated Sweet syndrome, and drug-induced Sweet syndrome 4, 3, 2.
- Classical Sweet syndrome usually presents in women between the age of 30 to 50 years, and may be related to infection, inflammatory bowel disease, or pregnancy 3, 2.
- Malignancy-associated Sweet syndrome can occur as a paraneoplastic syndrome in patients with an established cancer or individuals whose Sweet's syndrome-related hematologic dyscrasia or solid tumor was previously undiscovered 3.
Treatment of Sweet Syndrome
- Systemic corticosteroids are the therapeutic gold standard for Sweet's syndrome, and prompt response to treatment is typically seen 4, 3, 5.
- Other effective treatments include potassium iodide, colchicine, indomethacin, clofazimine, cyclosporine, and dapsone 4, 3, 5.
- Topical application of high potency corticosteroids or intralesional corticosteroids may be efficacious for treating localized lesions 3.
Diagnosis and Diagnostic Criteria
- The major diagnostic criteria of classical Sweet syndrome include sudden painful erythematous skin lesions, histopathologic evidence of a dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis 2.
- Minor criteria include pyrexia over 38 ℃, association with hematologic or visceral malignancies, inflammatory diseases, pregnancy or preceded by infection, prompt response to systemic glucocorticoid or potassium iodide treatment, abnormal laboratory values 2.
- The presence of both major criteria and two of the four minor criteria are required to diagnose classical Sweet syndrome 2.
Pathogenesis and Associated Conditions
- The pathogenesis of Sweet syndrome is unclear and varies according to the associated conditions, but one unifying mechanism is the aberrant activation, proliferation, and skin homing of neutrophils 5.
- Sweet syndrome has been associated with various conditions, including malignancies, autoimmune and infectious disorders, and inflammatory bowel disease 3, 2, 5.