Human sporotrichosis is an emerging disease caused by fungi of the genus Sporothrix, distributed worldwide, but mostly in tropical and subtropical regions. This disease is caused by traumatic inoculation of contaminated material (either animal or vegetal in origin) into the skin. Sporotrichosis cases caused by zoonotic transmission through felines have significantly increased over the last 20 years in Brazil. There is a spectrum of clinical outcomes, from classical lymphocutaneous and fixed forms to disseminated manifestations and extracutaneous lesions; however, hypersensitivity reactions related to sporotrichosis, including Sweet syndrome (acute febrile neutrophilic dermatoses), are uncommon. In Brazil, Sporothrix brasiliensis is repeatedly associated with feline infection and has consistently shown higher virulence, tendency to escalate to outbreaks or epidemics, and development of atypical forms. Therefore, the objective of the present study was to report the cases of 10 patients with sporotrichosis infected by S. brasiliensis species who developed Sweet syndrome to alert this association, especially in endemic areas.