D2.184 - Sensitization profile to vespid venom: limitations in clinical practice

Hymenoptera venom allergy is a significant cause of anaphylaxis in adults. In the Mediterranean region, Polistes dominula plays an important role in wasp allergy. Advances in molecular diagnostics have made it possible to better distinguish between primary sensitization and cross-reactivity, thus facilitating more accurate selection of venom for immunotherapy. However, the allergens available for wasps are limited. The aim of this study is to analyze the limitations of molecular diagnostics in patients allergic to wasps in our area.

A descriptive, retrospective study was conducted, including patients diagnosed with hymenoptera venom allergy between 2021 and 2025. Patients allergic to wasps were selected and demographic, clinical, and diagnostic data (skin tests, specific IgE to venoms, and molecular diagnosis) were collected, as well as information on hymenoptera venom immunotherapy (VIT).

Of the 76 patients studied, 61 (80.2%) were allergic to vespid venom. In this group, the median age was 44.8 years (IQR: 37.18-63.55), with a predominance of males (55.7%). In the majority (73.8%), the initial reactions were severe (Mueller grades 3 and 4). A REMA score ≥2 was detected in 27.1% and mastocytosis was diagnosed in 16.9%.

Skin tests were positive for Polistes dominula (82%) and Vespula spp (50.8%). The table shows the specific IgE and tryptase values. The final diagnosis was Polistes allergy in 63.9%, double sensitization to Polistes + Vespula in 18%, and Vespula allergy in 18%. Among those allergic to Polistes, 30% tested negative for Pol d 5, and of these, 77.8% tested positive for Ves v 1, suggesting sensitization to phospholipases.

Regarding VIT, 90% began treatment, showing excellent tolerance in both the initial and maintenance phases. Regarding efficacy, 24.9% of patients suffered spontaneous stings and 49% underwent sting challenge test, all with tolerance.

In our study, Polistes dominula was the most common cause of wasp allergy; however, in 30% of these patients, Pol d 1 would have been needed to make an accurate molecular diagnosis. Molecular diagnosis of vespid venom allergy needs to be improved, especially in the Mediterranean region, where double sensitization is common.