In vitro allergy investigation: Does a multiple allergen testing system give useful information?

Introduction: The Hitachi CLA allergy test gives individual results on a wide range of common allergens. This study looked at the effect on patient management of the extra information gleaned from the use of this test compared to the same patient being investigated under a protocol of a total IgE and 4 allergen specific IgE tests using the Pharmacia UNICAP system. Design, setting and patients: Fifty-four patients who presented to our Dermatology Department with possible Type I hypersensitivity: 19 males (10 were < 16 years); 36 females (12 were <16 years). Our standard investigative protocol using the Pharmacia UNICAP was applied to all samples; each was also tested using the Hitachi CLA system and the two sets of data compared. Results: The CLA system identified 22/54 patients in which one or more potentially significant allergens were found that would not have been identified by our current system of total IgE plus 4 allergen specific IgE results. Multiple positive allergens were detected by the CLA system in 13154 cases. 12/54 patients had no allergen that was positive CLA and the UNICAP. 3154 had positive results using our Pharmacia-based protocol that were not available by use of the extended panel. 4/54 patients had profiles in which both systems offered differing clinically useful information. Conclusion: These data support the use of a multiple allergen testing system to identify potentially significant individual allergens, patients in whom a Type I allergic reaction is unlikely or patients with multiple positive results for whom allergen avoidance is unlikely to be effective.