Brazilian pemphigus foliaceus, endemic pemphigus foliaceus, or fogo selvagem (wild fire).

Brazilian pemphigus foliaceus, also known as fogo selvagem, is the endemic form of pemphigus foliaceus occurring in certain regions of Brazil. Epidemiologic data strongly support the notion that this disease is caused by exposure to an environmental agent or agents. This form of pemphigus foliaceus is a true human autoimmune disease mediated by autoantibodies of the IgG class, IgG4 subclass. These autoantibodies are pathogenic and highly specific for the disease. The environment agent may sensitize the patient to produce autoantibodies. These autoantibodies may cross-react with the epidermis and induce disease in the patient.