[Prevalence of atopy in 1,199 asthmatic children from southern Santiago, Chile].

BACKGROUND

The prevalence of atopy in asthmatic children is widely variable around the world as demonstrated by large multicentric international studies.

AIM: To determine the prevalence of atopy, defined as a positive reaction to one or more allergens in the skin prick test (SPT), in children with persistent asthma.

MATERIAL AND

METHODS

We studied 1,199 children (54% male), aged between 4 and 16 years with confirmed diagnosis of asthma and followed at a Department of Pediatric Respiratory Medicine, between 2006 and 2011. SPT was performed according to international recommendations using standardized aeroallergens, in the forearm. A positive reaction was defined as a wheal ≥ 3 mm to one or more allergens.

RESULTS

The overall prevalence of atopy (positive SPT) was 49.4% (95% confidence interval (CI) 46.5-52.2) and there was a significant trend towards a higher prevalence with increasing age (p < 0.01). The main allergens with positive reactions were Dermatophagoides with 24.9% (95% CI 26.7-31.9), grass 24.0% (95% CI 21.6-26.5), weeds 19.0% (95% CI 16.9-21.4), cat 17.7% (95% CI 15.4-20.2), and Alternaria with 11.0% (95% CI 9.1-13.1). Sixty five percent of positive children reacted to one or more allergens. There were no adverse reactions.

CONCLUSIONS

In the southern metropolitan area of Santiago de Chile, half of children with asthma are sensitized to common aeroallergens.