Laboratory diagnosis of histoplasmosis: update 2000.

Histoplasmosis is a common infection in endemic regions of North and Latin America, causing a broad spectrum of clinical findings. Although acute pulmonary infection, chronic pulmonary, and progressive disseminated histoplasmosis are the most commonly recognized clinical manifestations, pericarditis, rheumatologic syndromes, esophageal compression, and sarcoid-like manifestations are well-recognized complications of histoplasmosis. Although excellent laboratory methods for diagnosis are available, diagnosis in many cases is missed or delayed because histoplasmosis is not considered in the differential. Physicians must be aware of the clinical syndromes and take advantage of epidemiologic clues. Furthermore, clinicians must be familiar with the uses and limitations of a battery of serologic and mycologic tests. Cultures, fungal stains, antigen detection, and serologic tests for antibodies are useful for diagnosis of histoplasmosis. All are reasonably specific and can serve as the basis for diagnosis in patients with compatible clinical findings. Each has certain limitations that must be recognized if they are to be used correctly. The approach to diagnosis of histoplasmosis will be reviewed.