Comparison of in vitro assay for specific IgE and skin prick test with intradermal test in patients with allergic rhinitis

Among many diagnostic tests for allergic rhinitis, the intradermal (ID) tes t is practical and reliable. However, there are several factors affecting c ompliance, practicability and interpretation, and also problems on hypersen sitivity of the ID. For these reasons, we evaluated other tests which have been thought to have high reliability as diagnostic and/or screening assays , namely, skin prick test and specific IgE detection in seventy-four perenn ial rhinitis patients (51 males and 23 females whose ages were between 15-6 0 years). In this study, Dermatophagoides pteronyssinus and D. farinae extr acts, known to be the most common aeroallergens in Thailand, were used as t he allergens/antigens. Compared to the standard ID test, sensitivities to D . pteronyssinus and D. farinae of the studied patients tested by skin prick test were 90.4% and 86.4%, and specificities were 99.5% and 93.1%, respect ively. Sensitivities to D. pteronyssinus and D. farinae using specific IgE assay were 96.3% and 88.9%, and specificities were 96.2% and 88.9%, respect ively. It was concluded that the skin prick test can be used as a screening method for patients with allergic rhinitis, while the specific IgE detecti on can be used as an alternative for diagnosis of patients who are suscepti ble to the ID test or for those who are severely susceptible to allergic rh initis such that medication can not be withdrawn for the ID test.