Sweet syndrome is a neutrophilic dermatosis with cutaneous tender lesions that can be associated with malignancies, infections, systemic inflammatory disorders, and medications. Although numerous studies have described Sweet syndrome, few studies have systematically investigated Sweet syndrome.

We sought to describe characteristics and treatments of patients with Sweet syndrome and evaluate clinical differences depending on the underlying cause.

A retrospective study was conducted to identify patients with Sweet syndrome evaluated at Mayo Clinic from 1992 to 2010.

Of 77 patients with Sweet syndrome (mean age of onset 57 years), 43 (56%) were male. Eighteen patients (23%) reported a preceding infection. A total of 41 (53%) patients were classified as having classic Sweet syndrome, 27 (35%) patients had malignancy-associated Sweet syndrome, and in 9 (12%) patients drug-induced Sweet syndrome was considered. In all, 21 patients had a hematologic malignancy or myeloproliferative/myelodysplastic disorder, whereas 6 patients had solid tumors. The mean hemoglobin level, in both male and female patients (P < .0443 and P < .0035, respectively), was significantly lower in malignancy-associated versus classic and drug-induced Sweet syndrome. Systemic corticosteroids were the most frequently used treatment (70%).

This is a retrospective study and represents patients from a single academic center.

Sweet syndrome is a distinctive disorder with certain clinical and histologic characteristics, which usually has a complete response to systemic corticosteroids. It is important to evaluate Sweet syndrome patients who have laboratory evidence of anemia for an underlying malignancy.