[Tricky cases in in-vitro diagnostics of hymenoptera venom allergy]

Abstract

Background: Hymenoptera stings give rise to anaphylactic reactions in 1.2-3.5 % of the population. The risk of repeat anaphylaxis following subsequent stings is greatly reduced through immunotherapy with the culprit venom. A prerequisite for allergen-specific immunotherapy is a precise diagnostic work-up.

Aims and objectives: We review the efficacy of currently available in-vitro diagnostic tests for hymenoptera venom allergy in different clinical scenarios.

Methods: A targeted literature review in PubMed and a review of the current guideline on hymenoptera venom allergy were performed. For illustrative purposes, a series of clinical cases from our allergy department are presented.

Results and conclusion: The correct diagnosis in hymenoptera venom allergy is influenced by a number of factors including patients' ability to identify the insect and time lapsed to diagnostic tests. The high rate of clinically irrelevant sensitizations, cross-reactivity and suboptimal sensitivity of the currently available diagnostic tests further complicate the picture. In the case of multiple sensitizations, molecular allergy diagnostics has improved the detection of clinically relevant sensitizations allowing the cost and risks of unnecessary double immunotherapy to be avoided. This is true in particular with regard to wasp venom allergy. For bee venom allergy, improvements in molecular allergy diagnostics have shown promising results and their implementation in clinical practice is planned. In patients with no sensitization in skin or serological tests but with a convincing history of insect sting anaphylaxis, the increased sensitivity of a basophil activation test may deliver crucial evidence of venom sensitization. The value of the basophil activation test may be further improved using specific marker allergens. The diagnosis of allergy to paper wasps (Polistinae) and white-faced hornets (Dolichovespula) remains problematic as they show partial cross-reactivity to wasp venom and specific marker allergens particular to these, still have to be identified.