Sweet Syndrome: Clinical Presentation, Malignancy Association, Autoinflammatory Disorders and Treatment Response in a Cohort of 93 Patients with Long-term Follow-up

Sweet syndrome is a neutrophilic dermatosis associated with multiple disorders. This retrospective case-series study of patients with Sweet syndrome in a tertiary hospital in Spain from 2001 to 2021, explores clinicopathological characteristics of Sweet syndrome and variables associated with malignancy, presence of autoinflammatory disorders and differences between histological subtypes. A total of 93 patients were identified: 30% idiopathic, 34% malignancy-associated, 29% reactive to infections or drug-associated, and 6% with an autoimmune/inflammatory condition. Acute myeloid leukaemia was the most common malignancy (16/93) followed by myelodysplastic syndrome (7/93). Patients with acute myeloid leukaemia presented isolated flares, marked cytopaenia and rapid response to treatment, whereas myelodysplastic syndrome followed a chronic-recurrent course. The most frequent associated medications and inflammatory disorders were filgrastim and hydroxyurea (n = 2); and inflammatory bowel disease (n = 4). In addition, 3 patients were diagnosed with VEXAS syndrome. Male sex (p = 0.006), fever (p = 0.034), increased erythrocyte sedimentation rate (p