Asthma in developing countries in the Asia-Pacific Region (APR).

There is growing interest in the epidemiology of asthma in developing countries, especially in the Asia-Pacific Region (APR). A number of reviews have been published in this field, but a comprehensive synthesis of overall data has not been reported. Here, we summarized the burden, risk factors and challenges of asthma management in developing countries with a specific emphasis on the APR by consolidating evidence from both systematic and narrative reviews published up until February 2023. We found that although asthma prevalence in low and low-middle-income countries (LMICs) is known to be generally lower compared to high-income countries, the burden is substantially greater. Studies conducted in APR LMIC have reported a range of risk factors, including pre- and post-natal factors, environmental considerations, lifestyle measures, individual features and genetics. The low and inequitable distribution of quality preventive and curative health care, a lack of advanced diagnostic measures, non-availability and non-affordability of novel therapeutics, cultural beliefs and practices, and diverse disease phenotypes make it challenging to achieve optimal asthma control in the region. Hence, we call for the development of a region-specific blueprint for action to mitigate this challenging situation, to help reduce the burden of asthma in APR LMIC.

Food hypersensitivity: an examination of factors influencing symptoms and temporal changes in the prevalence of sensitization in an adult sample.

BACKGROUND/OBJECTIVES: Food hypersensitivity (FHS) is common, but little is known about the factors associated with severe reactions, age of onset and whether sensitization persists. This study examines the factors associated with self-reported severe food reactions, onset age and the changes in prevalence of sensitization to foods over time in an adult sample. SUBJECTS/METHODS: We used data from adults taking part in the European Community Respiratory Health Survey (ECRHS) III (2010-2014) who provided information on food hypersensitivity, including symptoms, suspected culprit food and onset age (n = 4865). A subsample from six countries had serum food-specific IgE tested for 25 core foods and also in 10 years earlier (ECRHS II). We applied logistic regression and McNemar's test for analyses. RESULTS: The prevalence of self-reported FHS was 13.5% at ECRHS III. Of those providing information on symptoms (n = 611), 26.4% reported severe reactions. About 80% of 1033 reported food-specific reactions (reported by 596 participants) began after age 15. History of asthma (odds ratio OR 2.12 95% confidence interval CI 1.13-3.44) and a younger age of onset of FHS (OR 1.02, 95% CI 1.01-1.03, per year) were associated with higher risks of a lifetime experience of severe food reactions. In the subsample with IgE tested in both surveys (n = 1612), the overall prevalence of sensitization to foods did not change over 10 years. CONCLUSION: Our findings support previous observations of more severe food reactions in people with asthma and that most FHS reported by this sample started after age 15. We found no evidence of changes in the prevalence of sensitization to food in adults followed for 10 years.

Children With Food Allergy Are at Risk of Lower Lung Function on High-Pollen Days.

BACKGROUND: Grass pollen exposure is a risk factor for childhood asthma hospital attendances. However, its short-term influence on lung function, especially among those with other allergic conditions, has been less well-studied. OBJECTIVE: To investigate this association in a population-based sample of children. METHODS: Within the HealthNuts cohort, 641 children performed spirometry during the grass pollen season. Grass pollen concentration was considered on the day of testing (lag 0), up to 3 days before (lag 1-lag 3), and cumulatively (lag 0-3). We used linear regression to assess the relevant associations and examined potential interactions with current asthma, hay fever or eczema, and food allergy. RESULTS: Associations were observed only in children with allergic disease (P value for interaction ≤ 0.1). In children with food allergy, grass pollen concentration was associated with a lower ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) and lower mid-forced expiratory flows (FEF25%-75%) at all lags (eg, at lag 2, FEV1/FVC z-score = -0.50 [95% CI -0.80 to -0.20] and FEF25%--75% z-score = -0.40 [-0.60 to -0.04] per 20 grains/m3 pollen increase), and increased bronchodilator responsiveness (BDR) at lag 2 and lag 3 (eg, at lag 2, BDR = (31 [95% CI -0.005 to 62] mL). In children with current asthma, increasing grass pollen concentration was associated with lower FEF25%-75% and increased BDR, whereas children with current hay fever or eczema had increased BDR only. CONCLUSIONS: A proactive approach needs to be enforced to manage susceptible children, especially those with food allergy, before high-grass pollen days.