Progressive disseminated histoplasmosis in the acquired immunodeficiency syndrome: a model for disseminated disease.

Progressive disseminated histoplasmosis (PDH) is a relatively common infectious illness in human immunodeficiency virus (HIV)-infected patients. In Houston, Texas, (which is moderately endemic for histoplasmosis) the frequency of PDH is 5% among patients with acquired immunodeficiency syndrome (AIDS), almost as high as that of those with cryptoccal disease. In highly endemic areas, the frequency of PDH in AIDS is even greater, up to 75% in some areas. It is likely that as the HIV epidemic continues to penetrate to more remote, highly endemic areas, more and more cases of PDH will occur. It is also clear that PDH may develop in HIV-infected patients who presently live in nonendemic areas, but who previously resided in endemic areas. It is important that all physicians who care for HIV-infected patients become thoroughly familiar with the clinical manifestation of this illness. Timely diagnosis depends on a high degree of diagnostic suspicion since the illness seldom presents with primary respiratory symptoms. It is prudent to consider PDH in the differential diagnosis of any systemic, wasting, febrile illness in HIV-infected individuals, especially if currently or in the past they have resided in areas endemic for the fungus. Similarly, whenever PDH is diagnosed in any patient who is in a high-risk group for HIV infection, prompt testing for HIV should be performed.