The causative agent is a thermally dimorphic fungus, Paracoccidioides brasiliensis , which is isolated from the soil. Researchers believe that the disease is acquired by inhalation. Mortality in Brazil is estimated at 1486 per 1 million inhabitants. Some of this unequal distribution is attributed to exposure. Most patients are aged 30 years or older.
Most infections are subclinical.
The mycosis is polymorphic, often severe, and progressive. Upper respiratory tract and digestive tract ulcerations develop, most commonly in the mouth and nose. The ulcers are painful and can cause dysphagia, dysphonia, and tooth loss. Often, the patient may have coexisting lung, skin, and mucosal involvement. Lymphadenopathy is also a common presenting feature.