Cryptococcosis is a fungal infection caused by Cryptococcus neoformans, a world-wide distributed fungus which is commonly found in soil, especially that containing pigeon and avian droppings. Infection is acquired by inhaling spores of fungus 1.
Occur worldwide without any defined endemic areas. Cryptococcal infections in humans likely occur when the organism is aerosolized and inhaled 3.
The lungs, central nervous system, blood, skin, bone, joints, and prostate are the most commonly involved sites.
It occurs predominantly in immunocompromised patients but can also be seen in the normal host 1:
- immunocompetent host: cryptococcal infections are commonly localized to the lung and the patients are asymptomatic
- immunocompromised patient: cryptococcal infections often cause symptomatic pulmonary infections and then often disseminate to the central nervous system, skin, and bones
In fact, central nervous system infection after haematogenous dissemination is more common than pulmonary infection.
Serum cryptococcal antigen is helpful in diagnosis and follow-up of pulmonary and systemic disease. Antigen titers correspond to severity of illness. In CNS cryptococcosi, lumbar puncture is very helpful and shows increased CSF pressure, decreased glucose, increased protein, and mild to moderate leukocytosis. Indian ink test is highly specific and colors the thick round capsule of the yeast.