It is neutrophil-mediated, as evidenced by its histopathologic appearance, associated neutrophilia and response to medications that impact neutrophil activity. The association of exogenous granulocyte-colony stimulating factors with the development of Sweet syndrome also supports the importance of neutrophils and related endogenous cytokines in the underlying process. Additionally, some studies have suggested a role for tumor necrosis factor, and others an imbalance of type 1 helper T-cells. Although the skin is the primary organ affected, other systems, most notably the lung and kidney, can be involved. Since this condition can be associated with many other diseases, including malignancy, overall prognosis depends on the underlying cause.
Sweet syndrome has no known racial predilection.
This predilection has not been noted in series of cases associated with malignancy. Typically, female patients with Sweet syndrome are between 30 and 50 years old, while affected men develop the disorder between the sixth and ninth decades. Children as young as 7 months old have been described. Sweet syndrome in children is an extremely rare occurrence and is generally associated with infection. The crop of plaques or nodules often appears abruptly and may persist for days to weeks.