Comparative Study on the Allergy Skin Test and RAST in Allergic Patients

ABSTRACT

The allergic skin test and RAST are used commonly to demonstrate the presence of skin sensitizing IgE antibody in the diagnosis of allergic disease. To evaluate the agreement rate and correlation between results of skin test and RAST (radioallergosorbent test) in allergic subject, 83 allergic childhood with positive skin test (bronchial asthma 26, allergic rhinitis 27, atopic dermatitis and urticaria 6 bronchial asthma and allergic rhinitis 24) and 16 nonallergic childhood were studied. The results were as follows. 1) Peripheral eosinophil counts were significantly elevated in groups with bronchial asthma, allergic rhinitis, bronchial asthma & allergic rhinitis except atopic dermatitis & urticaria group in comparison with normal control group. 2) Serum IgE levels were significantly higher in groups with bronchial asthma, allergic rhinitis, bronchial asthma & allergic rhinitis than in normal control group except atopic dermatitis & urticaria group but there was no significant differences among study groups. 3) RAST units of D.p and D.f were significantly higher in study group except atopic dermatitis & urticaria group. RAST units of cockroach, however, were not significantly increased but in D.f, combined group of bronchial asthma & allergic rhinitis was significantly higher than bronchial asthma or allergic rhinits (p<0.05). 4) Each agreement rate between 3+ skin test and positive rate of RAST in D.p, D.f, cockroach was 37.5%, 63.6% and 12.5% respectively and 4+ skin test and positive rate of RAST was 84.0%, 89.1% and 38.4%. 5) Correlation coefficient between skin test and RAST was 0.71 in D.P, 0.59 in D.f and 0.23 in cockroach. In conclusion, there was difference in agreement rate between positive skin test and RAST to each allergen. Agreement rate between positive skin test and RAST was higher in D.p and D.f. These results suggest that RAST can be used simultaneously with skin test for detecting allergens.