D3.220 - Insect – Seafood Cross-Reactivity: A Combined Skin and Molecular Diagnostic Approach

Insect consumption has risen in industrialized countries due to their nutritional value and EU approval for marketing and consumption. Seafood-allergic patients may develop sensitization to insects via cross-reactive allergens, increasing the risk of allergic reactions. This study examines sensitization to edible insects in Europe (mealworm larvae, migratory locust, house cricket) in 19 seafood-allergic patients using skin prick tests and molecular diagnostics.

A prospective observational study was conducted on seafood-allergic patients who visited our Department. Prick-by-prick tests with mealworm larvae, migratory locust, and house cricket flours were performed on 19 patients with confirmed seafood allergy, as indicated by positive prick-by-prick test with any seafood and suggestive allergic reaction after it intake. Additionally, molecular diagnostics with inmunoCAP an ISAC including tropomyosin (Pen a1) and arginin kinase (Pen m2) were performed.

Among 19 seafood-allergic patients, sensitization to insects was observed in 10 (52.6%) for mealworm larvae, 9 (47.4%) for house cricket, and 3 (15.8%) for migratory locust. Molecular diagnostics revealed that 6 (31.6%) were sensitized to tropomyosin (Pen a1) and 4 (21.1%) to arginine kinase (Pen m2). Of the 6 sensitized to tropomyosin, 4 (66.7%) reacted to both mealworm larvae and house cricket, while 2 (33.3%) reacted to all three insects. Among the 4 sensitized to arginine kinase, 3 (75%) reacted to mealworm larvae and house cricket, and 1 (25%) to mealworm larvae and migratory locust. The remaining 9 (47.4%) patients with positive insect sensitizations were negative for both tropomyosin and arginine kinase, suggesting the involvement of other cross-reactive allergens.

The study highlights significant cross-reactivity between seafood and insects, with tropomyosin and arginine kinase sensitization present in a minority of cases. Further research is needed to identify other allergens involved and their clinical relevance.