Disseminated histoplasmosis most commonly occurs in immunocompromised patients living in the Ohio and Mississippi River Valleys. HIV-infected patients with disseminated histoplasmosis usually have a CD4 count <200 cells/mm3 and present with fever, weight loss, malaise, and pulmonary symptoms such as cough and dyspnea. Pulmonary symptoms predominate, and in severe cases, patients may present with acute respiratory distress syndrome. Patients may present with a diffuse papular rash in disseminated disease. Mediastinitis is a rare but serious complication of histoplasmosis. Urine and serum antigen testing carries a high sensitivity, but bronchoalveolar lavage may be needed to make the diagnosis in cases of pulmonary involvement. Serum LDH and alkaline phosphatase levels may be markedly elevated as well.
Management and Disposition
Disseminated histoplasmosis should be considered in any patient from an endemic region with moderate to advanced HIV infection and constitutional symptoms. Acutely ill patients with fever, weight loss, and functional decline should be admitted for evaluation treatment. Some patients with less severe disease may be treated with oral itraconazole but should be referred for evaluation and a definitive diagnosis.
Consider disseminated histoplasmosis in any patient with moderate to advanced HIV infection and constitutional symptoms, rash, and appropriate geographic exposure.
Disseminated Histoplasmosis. Skin lesions indicative of cutaneous involvement in an AIDS patient with disseminated histoplasmosis. (Photo contributor: Stephen P. Raffanti, MD.)
Pulmonary Histoplasmosis. Chest x-ray demonstrating severe miliary histoplasmosis in a patient with AIDS. The patient presented with fever, cough, and respiratory distress. (Photo contributor: Jake Block, MD.)
Pulmonary Histoplasmosis. CT scan from the same patient in Fig. 20.23. (Photo contributor: Jake Block, MD.)