Efficacy of a single diagnostic test for sensitization to common inhalant allergens

Background: UniCAP Phadiatop is a single laboratory test designed to determine the presence or absence of specific IgE to a variety of common inhalants. Its purpose is to aid in the differentiation of patients with symptoms attributable to allergic disease from other common causes. Methods: Consecutive children and adolescent patients (n = 145) at two centers were examined by having their history and physical examination performed by two board certified allergists. Their conclusions along with skin prick tests and specific IgE measurements regarding seven common inhalants (mite, oak, ragweed, grass, dog, cat, Alternaria) were compared with UniCAP Phadiatop test results. This was done using concordance of all test results. Attempts to resolve test discrepancies, when found, included specific RAST inhibitions, total IgE values, and physicians' judgment after testing. Results: All patients with resolved diagnoses (143 of 145, 103 positive and 40 negative) were identified correctly by the UniCAP Phadiatop test. Skin test results and specific IEE measurements correlated well, but neither correlated well with the history by itself, suggesting a minimal false-positive component of the history of 23%. UniCAP Phadiatop results demonstrated a quantitative relationship between the patient's score and the amount of IgE specific to these individual allergens. Conclusions: The UniCAP Phadiatop test was shown to be highly sensitive and specific in differentiating individuals who are sensitized to common inhalants from those who are not. This test is recommended to all physicians as an aid in diagnostic and referral decisions for patients suspected of having an inhalant allergic diathesis.