ABSTRACT
PURPOSE: Skin prick test and determination of allergen-specific IgE antibodies in serum are methods commonly used to diagnose allergies. Several studies indicate that skin test and specific IgE have roughly the same diagnostic precision, although discrepancies exist. The objective of this study was to evaluate the influence of total serum IgE on the relation between skin prick test and allergen-specific IgE antibody. METHODS: We performed skin prick tests using 14 major inhalant allergens and measured total IgE and specific IgE for two major allergens [Dermatophagoides farinae(D.f.) and Dermatophagoides pteronyssinus (D.p.)] in serum of 230 children with atopic asthma. RESULTS: Positivity of skin prick test was 92.2% for D.f., 89.6% for D.p., and 22.6% for cockroach. Allergen/Histamine(A/H) ratio and allergen-specific IgE score showed a positive correlation for D.f.(r=0.39, P<0.01), and for D.p.(r=0.38, P<0.01). Total serum IgE and allergen-specific antibody score showed a positive correlation for D.f.(r=0.50, P<0.01), and for D.p.(r=0.53, P<0.01). There was no correlation between total serum IgE and A/H ratio on skin prick test for the two allergens. However, total serum IgE had the tendency to increase according to the number of positive allergens on skin prick test. At each level of A/H ratio for D.f. and D.p. on skin prick test, patients with high total IgE had higher antigen-specific IgE scores than patients with low total IgE. CONCLUSION: Our results show that the relationship between skin prick test and antigen-specific IgE was influenced by the level of serum total IgE. This indicates that the level of serum total IgE should be taken into account when skin prick test and allergen-specific IgE are compared.