Cryptococcosis

GENERAL PRINCIPLES

• Cryptococcus neoformans is a ubiquitous yeast associated with soil and pigeon excrement.

• Disease is principally meningeal (headache and mental status changes) and pulmonary (ranging from asymptomatic nodular disease to fulminant respiratory failure).

• Infection typically affects patients with impaired cellular immunity and carries high morbidity and mortality. Although rare, infection in patients with end-stage liver disease has been associated with higher mortality compared to HIV-positive patients and should be considered when symptoms of cryptococcosis are present.

DIAGNOSIS

• Diagnosis via culture and histology tissue evaluation with the use of specific fungal stains are considered the gold standard.

• CrAg testing by latex agglutination or lateral flow assay is highly sensitive and specific in both serum and CSF.

• Distinguishing between disseminated disease and localized pulmonary and asymptomatic disease is fundamental to guide therapy. Any patient with CNS disease, positive blood cultures, or elevated serum CrAg and those with severe pulmonary disease should be considered to have disseminated disease. Disseminated disease warrants an LP to exclude coexistent CNS involvement. Always measure opening pressure, as elevated opening pressure (≥25 cm H₂O) has poor prognostic implications and must be managed with decompression, usually with serial LP or a lumbar drain.³⁴

TREATMENT

Treatment is dependent on the patient's immune function and site of infection (see Table 14-13). Management of elevated intracranial pressure is critical. Infectious disease consultation is recommended and has been associated with decreased 90-day mortality.