Paracoccidioidomycosis

Paracoccidioidomycosis (also known as Lutz-Splendore-Almeida disease or Brazilian blastomycosis) is a mycosis caused by the fungus Paracoccidioides brasiliensis. Sometimes called South American blastomycosis, paracoccidioidomycosis is caused by a different fungus than that which causes blastomycosis.

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Agent

P. brasiliensis is a thermally-dimorphic fungus distributed in Brazil and South America. The habitat of the infectious agent is not known but appears to be aquatic. In biopsies the fungus appears as a polygemulating yeast with a pilot's wheel-like appearance.

Disease

Paracoccidioidomycosis is a systemic mycosis caused by the dimorphic fungus Paracoccidioides. It frequently involves mucous membranes, lymph nodes, bone and lungs and requires some degree of host immunosuppression.

Primary infection is thought to be autolimited and almost asymptomatic as histoplasmosis or Valley Fever. In young people, there is a progressive form of the disease (akin of tuberculous septicemia in tuberculous priminfection) with high prostrating fever, generalized lymphadenopathy and pulmonary involvement with milliary lesions. This juvenile form has a more severe prognosis even with treatment. The most common form is the so called adult form of paracoccidioidomycosis that is almost certainly a reactivation of the disease.

Painful lesions with a violaceous hue in lips and oral mucosa are common as is cervical lymphadenitis teeming with polygemulating yeasts in the biopsy. In this form, differential diagnosis must be made with mucocutaneous leishmaniasis, yaws and TB.

Pulmonary involvement is also common, it starts as lobar pneumonia or pleurisy but without remission at ninth day; the patient remains febrile, coughs, loses weight and the X rays reveal milliary shadows throughout lung fields. Other organs can be involved, like bones, meninges, arteries and spleen but this is very rare.

Diagnosis is made with a biopsy of affected tissue, this shows the characteristic helm-shaped yeasts and culture shows the agent. Serology is also used in endemic areas.

Treatment

Sulphonamides are the traditional remedies to paracoccidiodomycosis. They were introduced by Oliveira Ribeiro and used for more than fifty years with good results. The most used sulfa drugs in this infection are sulfadimethoxime, sulfadiazine and co-trimoxazole. This treatment is generally safe but several adverse effects can appear, the most severe of which are the Stevens Johnson Syndrome and agranulocytosis. It must be continued for up to 3 years to obtain cure and relapse and treatment failures aren't unusual.

Antifungal drugs like Amphotericin B or Ketoconazole are also effective in clearing the infection but they are very expensive compared with sulphonamides.

During therapy fibrosis can appear and a surgery be needed to correct this. Other possible complication is Addisonian crisis. The death rate is around ten percent.