1 Answer

Causes
By Mayo Clinic staff
Although Sweet's syndrome may be associated with infections, the condition itself isn't infectious. Sweet's syndrome is typically divided into three categories, depending on its associations:

Idiopathic (classical). In most cases, the cause of Sweet's syndrome isn't known (idiopathic). Idiopathic Sweet's syndrome predominantly affects women between the ages of 30 and 50, and is often preceded by an upper respiratory or gastrointestinal infection. It's also been associated with pregnancy and inflammatory bowel disease.
Malignancy-associated. In about 20 percent of cases, Sweet's syndrome is associated with cancer (malignancy), most often acute leukemia. A few cases may be associated with a solid tumor, such as breast or colon cancer. Sweet's syndrome can occur as an early sign of a cancer, after diagnosis or as a sign of a recurrence. Fever is often present but skin lesions typically aren't preceded by an upper respiratory infection, as is the case with idiopathic Sweet's syndrome. Malignancy-associated Sweet's syndrome appears to affect men and women equally but among older adults, it's more likely to occur in women.
Drug-induced. Although uncommon, Sweet's syndrome may occur as a reaction to a medication, most commonly to granulocyte colony-stimulating factor, a hormone preparation designed to increase your white blood cell count. Other medications associated with Sweet's syndrome include certain antibiotics, oral contraceptives, diuretics and anti-epileptic drugs, among others. Once the offending drug is discontinued, Sweet's syndrome usually goes away.