Scars without wounds: spectrum of delayed manifestations of histoplasmosis outside of the endemic area.

This short series represents a spectrum of histoplasmosis usually described only in places where the infection is nearly universal. In fact, most of the patients in this series were born in such places (17 of 19 patients with complicated presentations; 2 had recent suspicious exposures). As young adults, they had moved away to pursue military life, usually in coastal areas where the evidence of infection with H. capsulatum is a statistical rarity. The implications of these observations are straightforward. At the clinical level, they focus on histoplasmosis as a possible cause of pulmonary, mediastinal, or other lesions of obscure etiology, whether or not the patient has recently lived in "the endemic area". The simple determination of CF gamma titers may heighten the index of suspicion, especially when not confounded by skin testing with histoplasmin, a practice which rarely provides useful information. [Table: see text] With regard to pathogenesis, it seems noteworthy that common form of histoplasmosis was not seen in this brief experience. That is the "marching cavity" described by Goodwin and Des Prez, and other forms of chronic cavitary disease. The absence of such lesions is consonant with the view that they require continuous exogenous infection for their development. As for the forms of histoplasmosis which were seen in this series, it appears that most of the illnesses developed outside of what is usually considered endemic areas. The term endemic, as construed medically, has been defined as "restricted to and constantly present in a particular country or locality". Such a construction is unduly pedantic and rigid for clinicians. A more probabilistic view is needed, with attention to the possible role of inapparent infection early in life and of environmental foci of infection in places where the organism is not notoriously present. The mobile nature of our society makes it likely that the radiographic manifestations of once-regional diseases such as this one will be encountered more generally than in the past.