Comparison of Multi-Test device skin testing and modified RAST results.

Abstract

The initial purpose of this study was to determine the potential correlation between allergy test results obtained with the Multi-Test skin testing method and the radioallergosorbent test (RAST) blood test (used as a "standard"). Twenty patients with a history and physical examination findings suggestive of inhalant allergy underwent both a Multi-Test system screen (14 antigens plus histamine and glycerine controls) and RAST testing. The relationship between wheal size and Multi-Test system grade for each antigen and the corresponding RAST class was studied. The correlation between positive Multi-Test system and RAST results was poor, with an average agreement by antigen of 56.26% and overall agreement of 67.86%. However, the overall agreement between negative Multi-Test system results (< or =1+) and negative RAST results (< or =class 1) was 95.15%, with an average agreement by antigen of 83.99%. On the basis of results of this preliminary study, it appears that a negative Multi-Test system result indicates that significant inhalant allergy is unlikely, whereas a positive Multi-Test system result necessitates follow-up with more definitive testing by additional skin testing or RAST.