paracoccidioidomycosis

Paracoccidioidomycosis is a systemic fungal infection caused by thermally dimorphic fungi Paracoccidioides brasiliensis and Paracoccidioides lutzii. It is endemic to rural areas of Latin America, especially Brazil, and predominantly affects men with occupational soil exposure. Infection begins after inhalation of airborne conidia, leading to a primary pulmonary phase that can be latent and may disseminate to other organs over time.

Clinically, paracoccidioidomycosis presents in several forms. Acute and subacute forms occur mainly in children and young adults and can involve multiple organs with fever, lymphadenopathy, and pulmonary symptoms. The chronic form, more common in adult men, often starts with pulmonary disease and progresses to mucocutaneous involvement, particularly in the mouth, tongue, lips, and nasal mucosa, producing painful ulcers and granulomatous lesions. Skin involvement is common and may appear as verrucous or ulcerated plaques. Adrenal or central nervous system involvement can occur in advanced disease.

Diagnosis relies on laboratory demonstration of the organism. Direct microscopic examination and culture of clinical specimens (sputum, mucosal scrapings, skin lesions) can reveal yeast with multiple buds arranged around a central cell, producing a “pilot wheel” appearance. Histopathology shows granulomatous inflammation with similar yeast forms. Serologic tests, such as immunodiffusion and complement fixation, detect antibodies in many patients, though serology may be less reliable for some strains. Culture and molecular methods can provide confirmation and aid in species identification.

Treatment typically involves antifungal therapy. Mild to moderate disease often responds to itraconazole for several months, while more severe disease or central nervous system involvement may require amphotericin B followed by azole therapy. Treatment duration is long, often 9–12 months or more after clinical improvement, with relapse possible. There is no vaccine, and prevention focuses on reducing exposure in endemic areas and early diagnosis and management.