Allergic diseases are rapidly increasing worldwide, with considerable regional variations. In Belgium, studies on paediatric aeroallergen sensitisation have been lacking.

This multicentre, epidemiological study analysed aeroallergen sensitisation patterns in children across seven hospitals in Southern Belgium, using retrospective skin prick tests data from 2023. Its secondary objective was to identify the most relevant aeroallergens and define a region-specific minimal panel optimising diagnostic efficiency.

A total of 3297 patients were included, with respiratory symptoms being the primary indication for testing. The overall skin prick test positivity rate was 46.2 %, with significant age-related variations, including a notably lower rate in children under 3 years (16.6 %). The most common allergens identified were house dust mites (63.9 %), grass pollen (43.5 %), Betulaceae pollen (35.9 %), and cat dander (31.1 %). Over 63 % of sensitised children exhibited polysensitisation, with its prevalence increasing with age. Two distinct five-allergen panels, one for children under 3 years and one for older children, capture over 95 % of sensitisation.

This study provides a real-life overview of aeroallergen sensitisation based on a large cohort of Belgian children. Two minimal five-allergen panels offer a cost-effective and region-specific diagnostic tool. Findings also highlight the limited positivity of skin prick tests in children under 3 years, underscoring the importance of adequate test performance and interpretation in this age group to ensure reliable results.