Allergic rhinitis in children: environmental factors

Prevalence and risk factors for asthma, rhinitis, eczema, and atopy among preschool children in an Andean city

Background

Limited data are available on prevalence and associated risk factors for atopy and allergic diseases from high-altitude urban settings in Latin America.

Objective

To estimate the prevalence of atopy, asthma, rhinitis, and eczema, and associations with relevant risk factors in preschool children in the Andean city of Cuenca.

Methods

A cross-sectional study was undertaken using a representative sample of 535 children aged 3–5 years attending 30 nursery schools in the city of Cuenca, Ecuador. Data on allergic diseases and risk factors were collected by parental questionnaire. Atopy was measured by skin prick test (SPT) reactivity to a panel of relevant aeroallergens. Associations between risk factors and the prevalence of atopy and allergic diseases were estimated using multivariable logistic regression.

Results

Asthma symptoms were reported for 18% of children, rhinitis for 48%, and eczema for 28%, while SPT reactivity was present in 33%. Population fractions of asthma, rhinitis, and eczema attributable to SPT were 3.4%, 7.9%, and 2.9%, respectively. In multivariable models, an increased risk of asthma was observed among children with a maternal history of rhinitis (OR 1.85); rhinitis was significantly increased in children of high compared to low socioeconomic level (OR 2.09), among children with a maternal history of rhinitis (OR 2.29) or paternal history of eczema (OR 2.07), but reduced among children attending daycare (OR 0.64); eczema was associated with a paternal history of eczema (OR 3.73), and SPT was associated with having a dog inside the house (OR 1.67).

Conclusions

A high prevalence of asthma, rhinitis, and eczema symptoms were observed among preschool children in a high-altitude Andean setting. Despite a high prevalence of atopy, only a small fraction of symptoms was associated with atopy. Parental history of allergic diseases was the most consistent risk factor for symptoms in preschool children.

Allergic rhinitis: prevalence and possible risk factors in a Gulf Arab population

BACKGROUND

Epidemiological studies mainly from Europe, the USA and Asia indicate a high prevalence of allergic rhinitis (AR) in modern societies. However, little is known about AR among the heterogeneous population of the United Arab Emirates (UAE).

OBJECTIVES

To estimate the prevalence of AR and its independent risk factors in Al-Ain City, UAE.

METHODS

We used a validated, self-administered questionnaire modified from the ISAAC study to collect data from a two stage randomly selected sample of 10 000 school children. Overall, 7550 subjects (aged 13 years and above, siblings, and their parents) responded. We assessed the prevalence of AR (both crude and standardized prevalence of previous 12 months) as well as the independent relationship of AR with age, gender, education, nationality and family history by means of logistic regression.

RESULTS

The response rate was 76%. A total of 6543 subjects (median age 30 years) were included in the final analysis. Self-reported prevalence of AR (having symptoms in the past 12 months) was 36%, while adjusted values for sex/age yielded a prevalence of 32%. Regression analysis revealed that AR was independently associated with family history, Arab origin, younger age, female gender and higher education.

CONCLUSIONS

The relatively high prevalence of AR found in this study may be attributable to modernization and genetic factors. Further studies on the impact of rapid environmental and cultural changes on AR in the Arab countries are needed and currently planned in conjunction with GA(2)LEN (Global Allergy and Asthma European Network).