Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is characterized by fever, peripheral neutrophilia, and a nonvasculitic neutrophilic cutaneous eruption. It can occur at any age but most commonly from 30 to 60 years old. Lesions can occur anywhere, but most frequently on the upper extremities, neck, and face; they are typically tender, well-demarcated erythematous plaques with an edematous periphery (pseudovesiculation). Some progress to ulcerations and hemorrhagic crusting. Variants have been isolated to the face (erysipelas-like) and the dorsal hands. The plaques generally cause a burning pain and are nonpruritic. Sweet syndrome is associated with preceding upper respiratory infections, vaccinations, medications, malignancies, inflammatory bowel disease, autoimmune connective tissue diseases, and pregnancy.
Management and Disposition
The associated diseases need to be considered. A dermatologist should be consulted for diagnosis confirmation and further evaluation.
Unless a specific infection is identified (Streptococcus, Yersinia, or Staphylococcus), antibiotics are not indicated.
Malignancies associated with Sweet syndrome account for 20% of cases; acute myeloid leukemia is the most common.
Although preceding infections can cause this rash, the lesions are not infectious.
Sweet Syndrome. This young woman complained of sudden onset of fever and painful skin lesions. WBC = 22,000 with neutrophilia. This constellation of symptoms suggests Sweet syndrome and was confirmed by histology. There is a hint of peripheral vesiculation on some lesions. (Photo contributor: Lawrence B. Stack, MD.)
Sweet Syndrome. Less obvious erythematous plaques on the foot. (Photo contributor: J. Matthew Hardin, MD.)
Sweet Syndrome. This is a variant called neutrophilic dermatosis of the dorsal hands. (Photo contributors: Samantha Yelley, DO; Miju Kurtzweil, DO; and Veronica Tucci, MD, JD.)