Insights Into the Pathogenesis of Sweet's Syndrome

Sweet's syndrome, also known as Acute Febrile Neutrophilic Dermatosis, is a rare inflammatory condition. It is considered to be the prototype disease of neutrophilic dermatoses, and presents with acute onset dermal neutrophilic lesions, leukocytosis, and pyrexia. Several variants have been described both clinically and histopathologically. Classifications include classic Sweet's syndrome, malignancy associated, and drug induced. The cellular and molecular mechanisms involved in Sweet's syndrome have been difficult to elucidate due to the large variety of conditions leading to a common clinical presentation. The exact pathogenesis of Sweet's syndrome is unclear; however, new discoveries have shed light on the role of inflammatory signaling, disease induction, and relationship with malignancy. These findings include an improved understanding of inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic contributions. Continued investigations into effective treatments and targeted therapy will benefit patients and improve our molecular understanding of inflammatory diseases, including Sweet's syndrome.

Neuro sweet syndrome: a systematic review. A rare complication of Sweet syndrome

Sweet's syndrome (SS) is an inflammatory disease characterized by fever, leucocytosis and distinctive skin lesions that histologically consist of a dermal infiltrate of neutrophils with nuclear fragmentation. Aseptic neutrophilic inflammation may occur also in other organs. Central nervous system involvement in SS, Neuro-Sweet's syndrome (NSS), is rare and reported especially among Asian patients. A systematic review of the literature has been performed to find articles reporting cases of SS with neurological involvement. The search terms: "Sweet's syndrome/disease with neurological involvement, Neuro Sweet Syndrome/Disease" were used in the Pubmed Database. Sixty-nine NSS patients including 46 males and 23 females, more Asian than Caucasian, have been described from 1983 to date. The average age was 48.7 year-old. The most representative neurologic symptom was the altered state of consciousness, followed by headache and memory disorders. Differently from SS with skin or other district involvement, NSS appears to be more common in Asian patients than in Caucasian ones and affects mainly the male sex in the third or fourth decade of life. A very wide range of symptoms and signs can occur, depending on which part of the nervous system is affected. Initial presentation is usually with the SS typical skin lesions followed by neurological involvement. However, also an opposite presentation or a simultaneous skin and nervous involvement may happen. Awareness of the possible neurological complications in SS is important to avoid unnecessary therapies for other forms of meningoencephalitis and lead to successful treatment with systemic corticosteroids.

Sweet syndrome in children

The objective of this study was to describe the clinical features of Sweet syndrome in children. Our study population consisted of seven children diagnosed with Sweet syndrome over a 22-year period. Age, sex, appearance and location of lesions, associated signs and symptoms, past medical history, pathology, and subsequent disease course were documented for each patient. Fever and typical lesions were reported in most of patients in our study. The majority of patients presented with less-typical findings, such as pustules, vesicles, bullae, oral ulcerations, atrophic scars, and evidence of pathergy. Of the seven children in our study, four were found to have a preceding nonspecific upper respiratory or gastrointestinal infection, and two were diagnosed with an underlying hematologic malignancy. Our results suggest that atypical lesions are relatively common in children with Sweet syndrome and that underlying malignancy is associated with a minority of cases of pediatric Sweet syndrome.