Pulmonary Histoplasmosis: Clinical and Imagistic Characteristics

Abstract

Histoplasmosis is a condition caused by infection with a fungus, called Histoplasma capsulatum. The fungus can be found in the environment in an inactive form (spores), particularly in soil with great amount of bird or bat droppings. Infection occurs when a person inhales the spores and sometimes it can become aggressive especially when the immunity is low or the person has been in contact with a very high amount of fungi. The magnitude of symptoms correlates with the amount of fungi in contact with the patient. About 90% of patients are usually asymptomatic or presenting very few symptoms. However, in immunosuppressed patients, the infection can spread and affect several organs and systems like eyes, liver, spleen, central nervous system, hematological manifestations, joint manifestations. In patients with pre-existing lung disease chronic pulmonary histoplasmosis is not uncommon.