Impact of age and allergen type on sensitization changes in children with chronic rhinitis.

Background: Aeroallergen sensitization evaluation aids in diagnosing and managing chronic rhinitis.

Objective: To investigate changes in allergen sensitization over time in children with rhinitis.

Methods: Children with chronic rhinitis who underwent aeroallergen skin prick tests (SPT) between 2009 and 2019 were re-evaluated with a second SPT between 2022 and 2024. Sensitization changes were assessed by comparing initial and re-evaluation SPT results. A negative converter was defined as a previously positive test that became negative.

Results: Among 300 children (mean age 11.5 years), positive SPT rates increased from 71.3 % to 83.7 % (p < 0.001). House dust mites (HDM) were the most common sensitization (77 %), followed by cockroaches (24 %). Sensitization patterns changed in 56.7 % of children. HDM sensitization increased across all age groups, while cat sensitization rose significantly in those initially tested before age 5. Negative conversion rates varied by allergen, highest for Careless Weed (85.7 %) and lowest for HDM (1.52 %). Children who became negative converters for Bermuda grass had smaller initial wheal sizes than those who remained positive (3 mm vs. 5.8 mm, p = 0.003).

Conclusion: Allergen sensitization patterns evolve over time, influenced by allergen type and patient age. Repeat testing may be necessary, especially for children with uncontrolled rhinitis.