Sweet's syndrome is a rare neutrophilic dermatosis. Typically, patients present with a sudden onset of tender erythematous skin lesions (papules, nodules, and plaques), of asymetrical distribution, located preferentially on the superior limbs, face and neck, associated whith high fever and neutrophilia. Histologicaly, there is a diffuse infiltrate of neutrophils located in the dermis. Most of the time idiopathic, it may be associated with a respiratory or gastro-intestinal infection, with inflammatory bowel disease, pregnancy and vaccination. A drug-induced form and a malignancy-associated form have been described. Based on illustrations and two clinical cases, we wish to focus on the diagnostic strategy and the management of this disease.