Dialyzed venom skin tests for identifying yellow jacket-allergic patients not detected using standard venom.

Background The chance of a nonspecific intradermal skin test response at venom concentrations greater than 1.0 μg/mL limits the diagnostic range and can interfere with the diagnosis of some affected patients. Objective To compare the diagnostic ranges and clinical detection rates of skin tests using dialyzed yellow jacket venom (DYJV) and undialyzed YJV (UYJV), particularly in patients who have had negative venom skin test results. Methods Both DYJV and UYJV from the same original lot were diluted from 100 μg/mL to skin test concentrations of 0.01, 0.1, 1.0, 3.0, and 10 μg/mL. Participants included 10 nonallergic controls, 20 patients with a positive history and positive skin test results using UYJV, and 24 patients with a positive history but negative skin test results using UYJV (17 of whom had a positive IgE anti-YJV serology). Results Dialyzed venom skin test results were positive at 10 μg/mL or less in 79% of patients with a positive history but negative skin test reactions using UYJV. The dialyzed venom skin test results showed a half-log shift to the left from the undialyzed venom results in linear regression analysis, indicating a greater detection rate with skin tests using DYJV. Results of skin tests with dialyzed venom were positive in 3 of 4 patients who had negative undialyzed venom skin test results and who experienced a systemic reaction to challenge stings. Conclusions The DYJV improves the ability of skin tests to detect yellow jacket allergy and should be subject to further study.