CROSS REACTIVITY OF SKIN PRICK TEST RESULTS TO ENVIRONMENTAL AERO-ALLERGENS

Abstract

Introduction To diagnose and adequately treat allergies, identification of specific allergens is crucial. Skin prick (SPT) or serum IgE testing determines sensitization to potential allergens. Consensus varies regarding degree of cross reactivity between aero-allergens. This retrospective analysis quantifies aero-allergen cross-reactivity from SPT. Methods 12202 patients’ quantitative SPT results and basic characteristics were obtained from a tertiary academic center's electronic medical record and de-identified. Data was analyzed using Spearman's rank correlation coefficients to detect non-linear associations between wheal sizes of SPT results. Results The highest correlation among grasses was 0.903 (Fescue and Red Top). Thirteen more grass pairs had correlation over 0.8 and nineteen 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, where only Kentucky Blue and Bermuda were tested (correlation 0.768, n = 9348). •Highest correlation among weeds was 0.74 (Lambs Quarter and Pigweed). Six more weed pairs had correlation over 0.7. •Highest correlation among trees was 0.724 (Palm and Alder). Six more tree pairs had correlation over 0.7. •Highest correlation among molds was 0.711 (Helminthosporium and Epicoccum). •Dust mite correlation between D. farinae and D. pteronyssinus was 0.848 (n = 10022). Heat maps of all spearman correlation coefficients are shown in Figure 1. Conclusions This study confirmed high degrees of cross reactivity between Northern grasses, but also showed a high degree of cross reactivity between Northern grasses and Bermuda grass. This has implications for simplification of SPT and immunotherapy protocols in the future. To diagnose and adequately treat allergies, identification of specific allergens is crucial. Skin prick (SPT) or serum IgE testing determines sensitization to potential allergens. Consensus varies regarding degree of cross reactivity between aero-allergens. This retrospective analysis quantifies aero-allergen cross-reactivity from SPT. 12202 patients’ quantitative SPT results and basic characteristics were obtained from a tertiary academic center's electronic medical record and de-identified. Data was analyzed using Spearman's rank correlation coefficients to detect non-linear associations between wheal sizes of SPT results. The highest correlation among grasses was 0.903 (Fescue and Red Top). Thirteen more grass pairs had correlation over 0.8 and nineteen 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, where only Kentucky Blue and Bermuda were tested (correlation 0.768, n = 9348). •Highest correlation among weeds was 0.74 (Lambs Quarter and Pigweed). Six more weed pairs had correlation over 0.7. •Highest correlation among trees was 0.724 (Palm and Alder). Six more tree pairs had correlation over 0.7. •Highest correlation among molds was 0.711 (Helminthosporium and Epicoccum). •Dust mite correlation between D. farinae and D. pteronyssinus was 0.848 (n = 10022). Heat maps of all spearman correlation coefficients are shown in Figure 1. This study confirmed high degrees of cross reactivity between Northern grasses, but also showed a high degree of cross reactivity between Northern grasses and Bermuda grass. This has implications for simplification of SPT and immunotherapy protocols in the future.