A Study of Clinical Correlations between Skin Test, Radioallergosorbent Test and Bronchial Provocation Test in House Dust Asthmatics

ABSTRACT

We evaluated the correlations between the allergy skin test for house dust radioallergosorbent test (RAST) and the bronchial provocation test for revealing the sensitivity of the skin test and RAST, and for aiding in the search for the causative allergen in house dust asthmatics. There was an overall 72.5% agreement between the prick test and RAST, a 73.8% agreement between the prick test and house dust bronchoprovocation test (HD-BPT), and a 71.3% agreement between HD-BPT and RAST. A positive RAST was found with a positive HD-BPT in 71.2% of cases, and if RAST was negative, HD-BPT was negative in 46.9% of cases. 69.6% of the positive cases on prick test (more than 21 mm of erythema) were positive with RAST. All of the cases with a negative skin reaction to the prick test were negative to RAST. A positive skin test was found with a positive HD-BPT in 77.1% of cases, and if the prick test was negative, the HD-BPT was negative in 50.0% of cases. 87.5% of cases with a RAST positive exhibited a positive result with HD-BPT. A significant correlation was found between the results of prick tests and those of RASTs in the early response group of HD-BPT, but not in the late and dual response groups. There were significant correlations between total serum IgE and the results of HD-BPT, and total serum IgE value and the results of RAST. The greater the size of the prick test, the greater the likelihood of a positive HD-BPT. All 5 cases with an end point of intradermal skin test of a 5 degrees -5(-l) X 10(-2) dilution of house dust noted a negative HD-BPT. There was no significant correlation between total serum IgE and total eosinophil count. There was no significant correlation between wheal and erythema size of prick test and PC20 of methacholine.