Protocol for a prospective multicenter cross-sectional observational study to investigate the role of air pollution on allergic rhinitis prevalence

Divergent Trends in the Prevalence of Children's Asthma, Rhinitis and Atopic Dermatitis and Environmental Influences in the Urban Setting of Zagreb, Croatia

BACKGROUND

Previous studies have reported that the allergy epidemic in developed countries has reached its plateau, while a rise is expected in developing ones. Our aim was to compare the prevalence of allergic diseases among schoolchildren from the city of Zagreb, Croatia after sixteen years.

METHODS

Symptoms of asthma, allergic rhinitis (AR) and atopic dermatitis (AD) and risk factors were assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. An allergic profile was determined by a skin prick test.

RESULTS

The prevalence of current, ever-in-a-lifetime and diagnosed AR of 35.7%, 42.5% and 14.9% and AD of 18.1%, 37.1% and 31.1% demonstrated a significant increase. The asthma prevalence has remained unchanged. The allergen sensitivity rate has remained similar, but pollens have become dominant. Mould and dog exposure are risks for asthma (OR 14.505, OR 2.033). Exposure to cat allergens is protective in AR (OR 0.277). Parental history of allergies is a risk factor in all conditions.

CONCLUSION

Over sixteen years, the prevalence of AR and AD, but not of asthma, have increased. The proportion of atopy has remained high. The AR/AD symptom rise is probably a consequence of increased pollen sensitisation united with high particulate matter concentrations. The stable asthma trend could be a result of decreasing exposures to indoor allergens.

The Association Between Air Pollutants and Daily Outpatient Visits for Allergic Rhinitis: A Time-Series Analysis Based on Distribution Lag Nonlinear Model in Chongqing, China

Background

Allergic rhinitis (AR) is a severe and the most common chronic allergic disease, affecting 10-40% of the world population. The effect of air pollutants on AR has been confirmed in clinical experiments.

Purpose

This study aimed to quantify the association between air pollutants and daily outpatient visits for AR in Chongqing, China.

Methods

Based on the data of AR outpatients in the primary urban area of Chongqing from 2016 to 2017, along with the atmospheric pollutants and meteorological data in the same period, the distributed lag nonlinear model (DLNM) and generalized additive model (GAM) were used to analyze the time-series. We examined the effects of the single and double pollutant models with a maximum lag day of 30 days. Effect estimates were described as relative risk (RR) and 95% confidence intervals (CIs) in daily outpatient visits for AR per 10 μg/m³ increases in PM_2.5, PM₁₀, SO₂, NO₂, O₃, and per 1 mg/m³ increase in CO.

Results

A single pollutant's O₃ level had an immediate positive effect on AR within two days, the relative risks (RR, 95% CI) were 1.066 (1.008-1.127), 1.057 (1.005-1.112) and 1.048 (1.002-1.097). PM_2.5 had a lag effect within 11-18 days, the max relative risks (RR, 95% CI) were 1.083 (1.010-1.160). Moreover, O₃, PM_2.5, PM₁₀, SO₂ and NO₂ had significant effects on AR in the two-pollutant model. The RR cumulative effect of PM_2.5 became more pronounced as the concentration increased. The cumulative effect of NO₂ was lesser than PM_2.5.

Conclusion

Air pollutants were associated with the daily outpatient visits for AR, which may have considerable implications for developing tailored health policies and services to prevent AR in Chongqing and even all over the world.

Prevalence of allergic rhinitis, related comorbidities and risk factors in schoolchildren

Background

The study aimed to determine the prevalence and risk factors of allergic rhinitis and related comorbidities in school-age children in Budapest, capital of Hungary. Data and epidemiological studies on this disease are still limited.

Methods

A cross sectional study was conducted in 21 representative and randomly selected primary schools in 2019. International Study of Asthma and Allergies in Childhood-based questionnaires (n = 6869) inquiring about prevalence and related risk factors of allergic rhinitis were distributed to all parents. The data were characterised with standard descriptive statistics: frequencies (percentages) and means for categorical and quantitative data, respectively.

Results

3836 of the questionnaires (1857 M/1979F) were completed. The prevalence of current allergic rhinitis was 29.3% (1043), physician-diagnosed allergic rhinitis was 9.7% (373), cumulative allergic rhinitis was 36.2% (1289) and current allergic rhinoconjunctivitis was 16.2% (577). The presence of physician diagnosed atopic disease–asthma (p < 0.0001, OR = 4.398, 95% CI 3.356–5.807), food allergy (p < 0.0001, OR = 2.594, 95% CI 1.995–3.378), and eczema (p < 0.0001, OR = 1.899, 95% CI 1.568–2.300)-were significantly related to an increased risk of cumulative allergic rhinitis. Significant factors associated with allergic rhinitis include male gender (p < 0.0001), family history of atopy (p < 0.0001), frequent upper respiratory tract infections (p < 0.0001), tonsillectomy (p = 0.0054), antibiotics given in the first year of life (p < 0.0001), paracetamol given in the first year of life (p = 0.0038), long-lasting common infections caused by viruses and/or bacteria before the appearance of the allergy (p < 0.0001), consumption of drinks containing preservatives or colourants (p = 0.0023), duration of living in Budapest (p = 0.0386), smoking at home (p = 0.0218), smoking at home in the first year of life (p = 0.0048), birds at home (p = 0.0119), birds at home in the first year of life (p = 0.0052), visible mould in the bedroom (p = 0.0139), featherbedding (p = 0.0126), frequent or constant heavy-vehicle traffic (p = 0.0039), living in a weedy area (p < 0.0001) and living in the vicinity of an air-polluting factory or mine (p = 0.0128).

Conclusions

The prevalence of allergic rhinoconjunctivitis in 6–12-year-old children in Budapest is higher than reported for most of the surrounding European countries. While asthma (OR = 4.398) is the most significant comorbidity, environmental factors such as birds at home in the first year of life (OR = 2.394) and living in a weedy area (OR = 1.640) seem to be the most important factors associated with AR. Strategies for preventive measures should be implemented.

Trial registration number: KUT-19/2019. The study was approved by the Ethics Committee at Heim Pál National Pediatric Institute,