Venom allergy testing: is a graded approach necessary?

BACKGROUND: Many institutions recommend a stepwise approach to intradermal testing for venom allergy. This is costly and uncomfortable for the patient. The rationale for this approach is the risk of potential adverse reactions to testing with the maximal dose alone. OBJECTIVE: To evaluate the safety of a single-step approach to venom allergy testing. METHODS: The authors retrospectively reviewed the charts of 300 consecutive patients with suspected hymenoptera venom allergy based on history who underwent venom allergy testing in a single allergist's clinic where a single-step protocol had been adopted. All patients had positive skin test reaction to at least 1 hymenoptera venom. Charts were reviewed for testing protocol used, results of testing, and reported immediate and delayed adverse reactions to testing. RESULTS: All patients underwent testing with an identical single-step protocol with an intradermal dose of 0.02 mL of a 1.0-μg/mL concentration of each of the 5 commercially available vespid and bee venoms. Only 1 patient reported an adverse reaction to testing, which was delayed until the morning after his visit. There were no immediate adverse reactions. The patient who had the delayed reaction was successfully started on venom immunotherapy subsequent to his reaction. CONCLUSION: A single-step venom allergy intradermal testing protocol with a 1.0-μg/mL concentration of commercially available extracts is a safe option, which, if adopted into practice, could lead to more streamlined care for patients and cost savings for the medical system.