Enhancement in recall antigen responses by frequent,repetitive skin testing with candida,mumps, and streptokinase-streptodornase in 38 normal adults

Summary Candida, mumps, and streptokinase-streptodornase (SKSD) were administered intradermally to 38 healthy adult volunteers at weeks 0, 2, 4–5, and 14 during two separate trials. Frequent, repetitive testing was used to determine (1) whether responses remained stable; (2) the relationship of erythema to induration; and (3) whether results would change when analyzed by different methods of comparing endpoints.When Candida, mumps, and SKSD were first administered, 63%, 76%, and 88% of the subjects responded with 5 mm induration by 48 h. Although little sex difference was noted for mumps and SKSD responses, more men responded to Candida (P=0.001). Erythema and induration were linearly correlated for Candida and SKSD, but the results were variable for mumps. With frequent repetitive testing, the mean induration arising in response to Canadida increased (P=0.001), as did the number of responses >15 mm (P=0.05). Similarly, the mean mumps-induced induration increased (P=0.01), as did the number of responses >10 mm (P=0.05). The mean SKSD-induced induration increased (P=0.08) in the first trial. During the second trial an SKSD overdosage occurred, which produced SKSD-specific anergy lasting for 25 weeks but not affecting Canadida and mumps responses. All enhanced induration responses decreased toward baseline levels during a 10-week rest period. The graded-response method of data analysis was more sensitive than the positive-negative or mean induration methods for detecting significant induration enhancement. Appropriate controls are needed for meaningful data analysis during repetitive skin testing with these antigens.