Factors influencing immediate responses to intradermal allergen administration in patients with respiratory allergy

Background:Immediate skin reactions to allergens are influenced by several factors, such as the amount of administered allergen, the level of specific IgE, releasability of mast cells and hyperresponsiveness of the target organ. Methods:For the evaluation of factors influencing immediate skin response to intradermal allergen administration, we measured the wheal size 15 min after intradermal injection of 0.01–0.02 ml of the following agents: whole-body extract of Dermatophagoides farinae, 1,000 allergy units/ml; histamine, 0.1 mg/ml, and codeine sulfate, 0.09% in saline, and determined total IgE level, specific IgE and IgG subclass antibodies to D. farinaein 53 patients with respiratory allergy. Results:Multiple regression analysis for factors influencing wheal size after intradermal injection of D. farinae, specific IgE antibody level to D. farinaeand wheal size after intradermal administration of histamine showed statistically significant results (R² = 0.42739, p = 0.0000; R² = 0.50243, p = 0.0185, respectively). Multiple regression analysis for factors influencing wheal size after intradermal administration in the group with high levels of specific IgE to D.farinae(RAST class 3 or more) showed that wheal size after intradermal administration of codeine was the only factor exerting a statistically significant influence (p = 0.0119). Conclusion:Based on the above results, we can state that immediate responses to intradermal allergen administration were influenced by the level of specific IgE and hyperresponsiveness of the target organ to histamine, but that the immediate skin allergic responses in the presence of high levels of specific IgE were partially but significantly influenced by the releasability of skin mast cells.