Prevalence of oral allergy syndrome in children with allergic diseases

Introduction: The oral allergy syndrome (OAS) is a particular type of food allergy rarely explored in the paediatric population that is already considered an adult problem.

Objective: Identify the prevalence of OAS, symptoms and pollen species associated with its presence in children affected by allergic diseases.

Methods: A cross-sectional study was conducted. Consecutive sampling included children from 6 to 14 years who needed allergy treatment for the first time. A structured questionnaire was carried out to collect demographic and clinical data and history of OAS. Besides sensitisation to various allergens, the skin prick-by-prick test was performed to corroborate sensitisation to food related to OAS. Prevalence of OAS and its association with pollens was established following the covariate adjusted logistic regression.

Results: 267 subjects were included. Overall prevalence of OAS was 8.9% (95%CI 6.1-13.1%). Prevalence of OAS for allergic rhinitis and asthma were 8.8% and 9.1%, respectively. In patients sensitised to pollen, the prevalence ranged from 9.6% to 12.2% depending on the type of pollen. 62.5% of children with OAS were sensitive to pineapple. After adjusting for gender and family history of atopic disease, trees from the Quercus species showed an association with OAS (OR=2.7, 95%CI 1.2-6.2).

Conclusions: OAS is not uncommon in our environment. Pineapple, a typical fruit from the region, was the main food related. Quercus sp., but not birch nor olive, was the pollen associated with this syndrome.