[Pyoderma gangrenosum and Sweet's syndrome : Cutaneous manifestations of autoinflammatory disorders].

Pyoderma gangrenosum and Sweet's syndrome are rare diseases that belong to the group of neutrophilic dermatoses and share several common characteristics. Although the two disorders differ clinically from each other, both diseases show pronounced dermal infiltration of neutrophils without evidence of primary vasculitis and respond well to immunosuppressive drugs. In addition, both diseases are often associated with other systemic and hematological disorders. Recent findings show that the neutrophil dermatoses can be considered as cutaneous manifestations of autoinflammation, demonstrating an interesting new aspect in the development of the diseases and additional therapeutic avenues.