Paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is an acute to chronic fungal infection caused by fungi in the genus Paracoccidioides, including Paracoccidioides brasiliensis and Paracoccidioides lutzii. It is endemic to Central and South America, and is considered to be a neglected endemic mycosis, a type of neglected tropical disease. Paracoccidioidomycosis (PCM) is an acute to chronic fungal infection caused by fungi in the genus Paracoccidioides, including Paracoccidioides brasiliensis and Paracoccidioides lutzii. It is endemic to Central and South America, and is considered to be a neglected endemic mycosis, a type of neglected tropical disease. Asymptomatic lung infection is common, with fewer than 5% of infected individuals developing clinical disease. Two presentations are known, firstly the acute or subacute form, which predominantly affects children and young adults, and the chronic form, predominantly affecting adult men. Most patients are infected before age 20, although symptoms may present many years later. The juvenile, acute form is characterised by symptoms, such as fever, weight loss and feeling unwell together with enlarged lymph nodes and enlargement of the liver and spleen. This form is most often disseminated, with symptoms manifesting depending on the organs involved. Skin and mucous membrane lesions are often present, and bone involvement may occur in severe cases. This acute, severe presentation may mimic tuberculosis, lymphoma or leukaemia. The chronic form presents months to years after the initial infection occurs and most frequently presents with dry cough and shortness of breath. Other symptoms include excess salivation, difficulty swallowing, and difficulties with voice control. Upper respiratory tract mucosal lesions may be present, as well as increased mucus production and coughing up blood. Both pulmonary and extrapulmonary involvement is common. Up to 70% of cases have mucosal involvement, with lesions often found in the mouth, oropharynx, larynx, and palate. Classic lesions are superficial painful granular ulcers, with small spots of bleeding. Paracoccidioidomycosis is caused by two species of fungi that can exist as a mold or yeast depending on temperature, P. brasiliensis and P. lutzii. In protected soil environments, near water sources, that are disturbed either naturally or by human activity, P. brasiliensis has been epidemiologically observed (although not isolated). A known animal carrier is the armadillo. In the natural environment, the fungi are found as filamentous structures, and they develop infectious spores known as conidia. Human to human transmission has never been proven. Primary infection, although poorly understood due to lack of data, is thought to occur through inhalation of the conidia through the respiratory tract, after inhaling fungal conidia produced by the mycelial form of P. brasiliensis. This occurs predominantly in childhood and young adulthood, after exposure to agricultural activity. Infection may occur through direct skin inoculation, although this is rare. After inhalation into the alveoli, there is rapid multiplication of the organism in the lung tissue, sometimes spreading via the venous and lymphatic systems. Approximately 2% of people develop clinical features after the initial asymptomatic infection.