Calculating the prevalence of atopy in children.

Background: Atopy is an important risk factor for asthma, rhinitis, atopic eczema and urticaria. For this reason, several studies have been done to determine the prevalence of atopy in the paediatric population. The important differences among these studies do not allow the extrapolating of results. In this study, we calculate the prevalence of atopy and atopy-related diseases in a paediatric population using a different methodology.

Methods: Retrospective study among children referred for drug allergy in which the latter was discarded. We evaluated the prevalence of atopy (measured by allergen sensitisation), asthma, rhinitis, urticaria, atopic eczema and their characteristics.

Results: Three hundred and forty-two patients were studied for adverse drug reaction. This was discarded in 325/342 patients. 20 % of the children in the sample were atopic. Atopy prevalence increased with age. Some atopy related disease was observed in 83/325 (25.5 %) children. Among these children allergen sensitisation increased from 42.3 % in the 0-3 years age group to 93.3 % in the 7-14 age group (p < 0.0001). Prevalence of asthma was 11.5 %, 10.2 % and 7 % in the 0-3, 4-6 and 7-14 age groups, respectively. Prevalence of rhinoconjunctivitis increased through age groups with a prevalence of 20 % among the 7 to 14-year old children.

Conclusion: The use of this type of methodology seems to be correct to estimate the prevalence of atopy. Prevalence of allergen sensitisation is very high among 7 to 14-year old children with asthma and/or rhinoconjunctivitis.