Paracoccidioidomycosis is a chronic systemic fungal disease, probably respirator- or gastrointestinal in origin, with dissemination to the lymph nodes, skin, lung, and other organs.
History of Paracoccidioidomycosis.
Lutz in 1908 first described the disease and the organism observed in tissues of a Brazilian patient. In 1909 and 1912, Splendore described more fully the characteristics of the disease and the fungus.
Etiology of Paracoccidioidomycosis.
The disease is caused by a dimorphic fungus, Paracoccidioides brasiliensis, which appears in tissues and exudates as a multiple-budding yeast like organism 2 to 60 /a in diameter. The bud is characterized by a thin wall (0.2 to 1.0 fj.) and narrow pore. At temperatures less than 30° C. on Sabouraud glucose medium, a white (later brown) membranous or wrinkled mycelium appears that microscopically is composed of branching hyphae and oval forms (conidia). Delayed cutaneous hypersensitivity and complement-fixing antigens have been demonstrated. Guinea pigs and mice can be experimentally infected.
Epidemiology of Paracoccidioidomycosis.
Except for a report of one patient from Oregon, the disease occurs exclusively in residents of Central and South America and is especially prevalent in Brazil. It is approximately ten times more frequent in males, and is slightly more frequent in persons 40 to 50 years of age. Manual laborers and farmers seem especially susceptible. Infection is considered to be exogenous, but a saprophytic, environmental source of fungi is not known. Disease in animals and animal-to-man or man-to-man spread are unknown. Widespread infection of a benign form has been suggested by skin test surveys.
Pathology of Paracoccidioidomycosis.
The histopathologic reaction to P. brasiliensis may be suppurative with abscess formation; in other sites it may be granulomatous with fibroblasts, macrophages, lymphocytes, caseation, and giant cells containing organisms. Lesions are seen in the mucosa of the gastrointestinal tract, lymph nodes, spleen, lungs, and liver.
The primary lesion is commonly on the oral or nasal mucosa. Rarely, the conjunctival or anorectal mucosa may be involved. The earliest lesion is a papule that ulcerates and spreads to adjacent tissue.
Cutaneous Form of Paracoccidioidomycosis.
A variety of skin lesions may be seen, most of which progress to an ulcerative, crusted form suggestive of blastomycosis. In contrast, however, regional lymphadenopathy frequently accompanies skin lesions only in paracoccidioidomycosis. A keloidal form (Lobo’s disease) of milder nature, without lymphadenopathy and caused by a different species (P. loboi), may be another type of paracoccidioidomycosis.