A COMPARISON OF COCCIDIOIDIN AND SPHERULIN SKIN TESTING IN THE DIAGNOSIS OF COCCIDIOIDOMYCOSIS

Abstract

The reactivity to spherulin (coccidioides-immitis) was compared with coccidioidin in hospitalized patients with proved coccidioidomycosis. Patients were divided into 4 groups by type of disease (active pulmonary disease, inactive pulmonary disease, unifocal dissemination and multifocal dissemination). Skin test reactions were measured in mm, 48 h after antigen was injected. Reactions were reported. Evidently, coccidioidin 1:100 and spherulin skin test reactions were not significantly different from each other. Both were significantly smaller in the multifocal dissemination group than in the other groups, P .ltoreq. 0.05. In study patients on whom simultaneous paired observations of both reagents were made, 43% reacted to both reagents, 43% reacted to neither reagent and discordance was observed in 14%, equal in both directions. Of patients with reactivity to at least 1 noncoccidioidal skin test reagent, 34% failed to react to either coccidioidin or spherulin. Skin tests must be interpreted with careful consideration of the clinical presentation. Variation in skin test reagent preparations and standardization must be considered. There was no significant difference between the rate or size of reactions when tested with spherulin or coccidioidin 1:100. Lack of reactivity appears to be due to defects in immune function and not to lack of antigenic moieties in the antigen preparation.