Correlation of skin prick testing to environmental allergens

Abstract

BackgroundTo diagnose and adequately treat allergies, identification of sensitizing allergens is crucial. Skin prick or serum immunoglobulin E testing determines sensitization to potential allergens. Consensus varies regarding degree of cross-reactivity between aeroallergens. ObjectiveTo quantify correlations between aeroallergen skin prick test results. MethodsA total of 11,832 patients’ quantitative skin prick test results and basic characteristics were obtained from a tertiary academic center’s electronic medical record and deidentified. Data were analyzed using Spearman’s rank correlation coefficients to detect nonlinear associations between wheal sizes of skin prick test results. ResultsThe highest correlation among grasses was 0.903 (fescue and red top). Of note, 13 more grass pairs had correlation more than 0.8, and 19 had correlation between 0.7 and 0.8. The Northern grass comparative results are from a satellite clinic that tested more grasses than the main clinic, in which only Kentucky blue and Bermuda were tested (correlation 0.768; n = 9348). Highest correlation among weeds was 0.74 (lambs quarter and pigweed). In addition, 6 more weed pairs had correlation more than 0.7. Highest correlation among trees was 0.724 (palm and alder) and 6 more tree pairs had correlation more than 0.7. Highest correlation among molds was 0.711 (Helminthosporium and Epicoccum). Dust mite correlation between Dermatophagoides farinae and Dermatophagoides pteronyssinus was 0.848 (n = 10,022). ConclusionThis study confirmed the expected high degrees of correlation not only between skin prick test results of related environmental allergens but also between less closely related Northern grasses and Bermuda grass. This has implications for simplification of testing and immunotherapy protocols in the future.