Combining Discordant Serum IgE and Skin Testing Improves Diagnostic and Therapeutic Accuracy for Hymenoptera Venom Hypersensitivity Immunotherapy

Background: Diagnosis of patients with hymenoptera venom hypersensitivity consists of elucidating clinical symptoms suggestive of systemic reaction (SR) and then confirmation of sensitization via intradermal skin testing (IDST) first and serum IgE assays such as ImmunoCAP (ICAP) as a complementary modality of diagnosis. Objective: Determine the concordance between ICAP and IDST in patients with a clinical history suggestive of hymenoptera venom SR. Determine whether venom immunotherapy would change on the basis of IDST versus ICAP results. Methods: A prospective diagnostic study was designed to test the concordance between IDST and ICAP venom testing in the diagnosis of hymenoptera venom hypersensitivity. This study entailed testing both IDST and ICAP for 5 hymenoptera venoms (honey bee, wasp, yellow jacket, yellow hornet, and white-faced hornet) in both a case group with SR to hymenoptera venom (N = 70) and a control group without SR (N = 51). Results: Significant discordance was observed between positive IDST and ICAP results for any of the 5 hymenoptera venoms (McNemar test, P = .001). In the case group, there was significant discordance for wasp (P < .0001), yellow jacket (P = .002), and white-faced hornet (P = .02). More than 47% of the case patients would have different venom immunotherapy prescriptions if ICAP and IDST had been performed during initial diagnosis versus IDST alone. Conclusions: Our study shows significant discordance between IDST and ICAP; however, they are complementary. On the basis of our data, we propose ICAP testing first followed by IDST for ICAP-negative venoms as an alternative and efficient diagnostic strategy.