Disseminated Histoplasmosis With Lung and Liver Involvement in an Immunocompetent Patient.

Histoplasmosis, caused by the fungus Histoplasma capsulatum, is a significant public health concern in endemic regions like Mexico. Immunocompromised individuals, especially those with HIV infection and those exposed to nitrogen-rich environments, such as bird excrement or bat guano, are particularly vulnerable. This case report describes a middle-aged patient with jaundice in the skin and mucous membranes. Suspecting cholecystitis, abdominal imaging was performed, revealing hepatomegaly and bilateral pulmonary infiltrates with consolidations and nodular lesions on computed tomography. After being transferred to the internal medicine unit, a comprehensive diagnostic evaluation was carried out. Despite negative results from HIV serology and acid-fast bacillus testing, the patient tested positive for urine Histoplasma antigen, confirming the diagnosis of disseminated histoplasmosis. This case underscores the importance of considering histoplasmosis in the differential diagnosis of patients with relevant risk factors presenting with systemic symptoms.