RESUMO
We report the case of an 18-year-old immunocompetent man who presented to the hospital with fever, headaches, and arthromyalgia, which progressed to include an erythematous rash. He had a history of a tick bite 72 h earlier. The diagnosis of rickettsial infection was suspected and a course of doxycycline was initiated for a total of 5 days. His evolution was rapidly favorable under treatment, with resolution of the symptoms within 24 h. Blood cultures came back positive for Neisseria meningitidis serotype B, indicating an authentic purpura fulminans. Purpura fulminans is a medical emergency, a syndrome of intravascular thrombosis characterized by a very rapid evolution that requires early recognition and specific treatment. It is commonly described in the young and healthy patient and has high mortality and morbidity. Common bacteria mainly associated with purpura fulminans are Meningococcus spp., Pneumococcus spp., and Staphylococcus spp.