From the Guidelines
Sweet syndrome is a rare inflammatory skin condition characterized by tender, red inflammatory nodules or papules, usually affecting the upper limbs, face or neck, and is part of the group of acute neutrophilic dermatoses. The condition has been recognized as an extraintestinal manifestation of inflammatory bowel disease (IBD) and is more common in women and patients with colonic involvement and other extraintestinal manifestations 1. Some key features of Sweet syndrome include:
- Tender, red or purple bumps or plaques that may develop pustules
- Mostly associated with active disease
- Strong predilection for women and patients with colonic involvement and other extraintestinal manifestations
- Can be distinguished from other conditions by its appearance, distribution, and histological features The standard treatment for Sweet syndrome involves systemic corticosteroids, which have been reported to be effective 1. It is worth noting that the exact pathophysiology of Sweet syndrome remains incompletely understood, but it is thought to result from an abnormal immune response causing neutrophil infiltration in the skin.
From the Research
Definition and Characteristics of Sweet Syndrome
- Sweet syndrome (SS) is a rare skin disease characterized by sudden onset of fever, leukocytosis, neutrophilia, and tender erythematous plaques infiltrated by neutrophils 2.
- It is also known as acute febrile neutrophilic dermatosis, and is considered the prototype of neutrophilic dermatoses 3.
- The syndrome presents with tender, erythematous, edematous papules or plaques, often accompanied by fever 4.
Clinical Presentation and Associations
- Clinical presentation is mainly characterized by erythematous and edematous plaques, mostly on upper extremities and trunk 2.
- Fever is observed in 32% of patients, and 60% present with leukocytosis and 39% with neutrophilia 2.
- Sweet syndrome can be classified into classical or idiopathic, malignancy-associated, and drug-induced forms 5, 3.
- Multiple conditions have been associated with Sweet syndrome, including malignancies, autoimmune and infectious disorders 2, 4.
Pathogenesis and Treatment
- 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 4.
- The mainstay of treatment remains systemic corticosteroids, with alternatives including colchicine, dapsone, and potassium iodide 5, 4.
- Traditional immunosuppressants, biologic agents, and small molecules have also been described as effective in treating Sweet syndrome 4.
- Recent evidence suggests that not only innate but also adaptive immunity might play roles in the pathogenesis of Sweet syndrome, with a potential significant role of IL-17 axis 3.