Abstract
Background
Asthma and atopic dermatitis (AD) represent significant global health challenges in children. This study aimed to investigate trends in incidence, prevalence, and disability-adjusted life years (DALYs) for childhood asthma and AD from 1990 to 2021.
Methods
The study utilized information from the Global Burden of Disease (GBD), Injuries, and Risk Factors Study 2021. The sample size for this study consisted of children with asthma or AD between the ages of 0 and 14. From 1990–2021, we calculated asthma and AD’s age-standardized incidence, prevalence, and DALYs by area, age, sex, and socio-demographic index.
Results
In 2021, global childhood asthma prevalence reached 95.7 million cases (age-standardized rate: 4,758 per 100,000), with the Low SDI region recording 25.4 million cases. For AD, global prevalence was 72.4 million cases (age-standardized rate: 3,600 per 100,000), predominantly in Middle SDI regions (19.7 million cases). Between 1990 and 2021, age-standardized incidence rates decreased for both conditions. Geographic variations were notable: High-income North America showed the highest asthma incidence, while Western Europe led in AD prevalence. The global burden of asthma-related DALYs declined from 6.9 million in 1990 to 4.6 million in 2021, with significant regional disparities.
Conclusions
Despite decreasing age-standardized rates, childhood asthma and AD continue to pose substantial health burdens globally, with marked variations across regions and socioeconomic strata. These findings emphasize the need for targeted, region-specific interventions.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12890-025-03518-y.
Keywords: Allergic disorders, Global Burden of disease, Disability-adjusted life years, Incidence, Prevalence
Introduction
The prevalence of allergic diseases has experienced a significant rise over the years, currently impacting approximately 10 to 30 percent of the global populace [1–3]; they are more prevalent in preschoolers, and the prevalence is higher in developed nations than in developing nations [4]. Both asthma and atopic dermatitis (AD) may present themselves clinically in a variety of ways, and these manifestations often evolve as patients age [5–7].
The economic impact of childhood asthma is substantial, with annual direct medical costs reaching $5.92 billion in the United States alone [8]. AD management similarly imposes significant financial burdens on families, with annual costs ranging from $364 to $3,799 per patient [9]. These conditions also substantially affect quality of life, as evidenced by asthma-affected children missing an average of 2.3 more school days annually compared to their healthy peers [10]. Our specific focus on asthma and AD stems from their status as the predominant chronic inflammatory conditions in childhood, demonstrating higher prevalence rates than other allergic diseases. The early onset of these conditions, their chronic nature, and profound impact on childhood development position them as critical targets for public health intervention and epidemiological research.
Given the importance of mitigating non-communicable diseases in children, reducing the burden of allergic diseases remains a crucial objective. Regular assessment of the Global Burden of Disease (GBD) database for childhood allergic diseases is therefore essential to inform preventive strategies and minimize long-term complications associated with these conditions.
Methods
Data acquisition and download
The GBD 2021 study provides a comprehensive evaluation of health detriments associated with 369 diseases, injuries, and impairments, as well as 88 risk factors, spanning 204 countries and territories [11, 12]. To ensure robust estimates, GBD 2021 implemented rigorous uncertainty analysis protocols, typically generating 500 simulations per population group. This approach, combined with the reporting of 95% uncertainty intervals (UIs), provided reliable ranges for disease burden estimates. The study synthesized data from multiple sources, with asthma assessment primarily drawing from population-representative surveys, notably the International Study of Asthma and Allergies in Childhood collaboration [13]. This core dataset was supplemented with health service records, medical claims, surveillance data, and systematic literature reviews. For AD, the assessment integrated physical examination records, claims data, population surveys, literature reviews with standardized diagnostic criteria, and medical records stratified by severity based on physical manifestations and symptom intensity [13]. Data quality exhibited marked regional heterogeneity. High-income nations typically provided robust, standardized data through well-established healthcare systems and surveillance programs. In contrast, low- and middle-income countries often relied on more limited surveys and estimates, potentially introducing accuracy variations in burden assessments. To mitigate these disparities, the GBD methodology employed sophisticated analytical tools, including Cause of Death Ensemble modeling, Spatiotemporal Gaussian Process Regression, and Disease Modeling-Meta regression 2.1. These statistical approaches effectively addressed data heterogeneity and enhanced the consistency of epidemiological parameters across different regions and data sources [13].
To summarize the burden of allergic disease in children based on age distribution, we categorized patients into 3 groups: under 5 year, 5–9 years, and 10–14 years. We then utilized linear regression to calculate the mean estimated annual percentage changes (EAPCs). Additionally, we collected data on global risk factors contributing to asthma-related DALYs and mortality in children. For risk factors analysis, we extracted data directly from the GBD 2021 database, which provided comprehensive information on various risk factors associated with asthma, including environmental, occupational, and metabolic risks. The GBD 2021 study employed sophisticated statistical methods to evaluate the relationships between these risk factors and disease burden, using population attributable fractions to quantify the contribution of each risk factor to the disease burden. Risk factors for asthma were categorized into environmental/occupational risks and behavioral risks. However, risk factor analysis for AD was not included in our study as the GBD 2021 database does not currently contain risk factor data specific to AD, reflecting the complex and multifactorial nature of this condition. For GBD studies, a waiver of informed consent was reviewed and approved by the Institutional Review Board of the University of Washington. In the conduct and reporting of our study, we have rigorously adhered to the STROCSS criteria [14].
Case definition
The GBD 2021 study classified asthma according to ICD-10 (codes J45, J46) and ICD-9 (code 493) criteria. The condition was defined as a chronic respiratory disease manifesting as bronchospasm and breathing difficulties due to allergic or hypersensitivity reactions, with cases confirmed through physician diagnosis and documented wheezing in the preceding year.AD, corresponding to ICD-10 code L20 and ICD-9 code L691, was defined as a chronic, relapsing inflammatory skin condition marked by pruritus, elevated serum immunoglobulin E, and immune dysregulation, with either localized or generalized presentation [15, 16].
Sociodemographic index
The Sociodemographic Index (SDI) serves as an indicator of a country’s or region’s developmental status [17]. The SDI ranges from 0 to 1, with higher values indicating greater socioeconomic development. In this study, countries and geographic regions were classified into five SDI regions (high, high-middle, middle, low-middle, and low) to explore the association between the burden of childhood allergic diseases and socioeconomic development.
Statistical analysis
The prevalence, incidence and DALYs was represented as a projection for every 100,000 persons individuals in the populace, inclusive of its 95% UI [18]. The dynamics of childhood allergic diseases were analyzed by calculating EAPCs to identify temporal trends in the disease burden. The 95% CIs of the EAPCs were determined using linear modeling. If the upper limit of both the EAPC and its 95% CI is negative, the corresponding rate shows a decreasing trend; conversely, if the lower limit of both the EAPC and its 95% CI is positive, the corresponding rate shows an increasing trend. Additionally, risk factors for childhood allergic diseases were assessed. All procedures for analysis and graphic representation were performed utilizing the World Health Organization’s Health Equity Assessment Toolkit and the statistical computing software, R (Version 4.3.2). This study is a secondary analysis of publicly available data from the GBD study. As an ecological study using aggregated, de-identified data, it does not involve individual patient data or interventions. Therefore, this research does not meet the criteria for clinical trial registration.
The GBD study uses deidentified data, and a waiver of informed consent was approved by the University of Washington Institutional Review Board.
Role of the funding source
The funders of this study had no role in study design, data collection, data analysis, data interpretation, or the writing of the report.
Results
Global and regional burden of allergic disorders in children
Prevalence
In 2021, there were approximately 95.7 million cases of childhood asthma globally. The global age-standardized prevalence rate (ASPR) showed a significant decline of 30.4% from 1990 to 2021 (from 6,835.37 to 4,757.84 per 100,000 population), with an EAPC of -0.97 (95% CI, -1.17 to -0.78) (Table 1, Fig. 1). Children aged 5–9 years consistently showed the highest prevalence across the study period (Figure S1), with boys generally showing higher prevalence than girls (Figure S2).
Table 1.
Prevalence of Asthma in Children Between 1990 and 2021 at the Global and Regional Level
| Location | 1990 | 2021 | EAPC(95%CI) | ||
|---|---|---|---|---|---|
| Number(95%UI) | ASR(95%UI) | Number(95%UI) | ASR(95%UI) | ||
| Global | 118877436.25 (92834726.66–154141572.51) | 6835.37 (5337.93–8863.03) | 95721185.84 (73498677.61–125809130.41) | 4757.84 (3653.27–6253.37) | -0.97 (-1.17–0.78) |
| High SDI | 16704527.79 (12467060.51–22696809.87) | 8990.22 (6709.65–12215.21) | 15669744.27 (11857643.44–21052131.02) | 9081.99 (6872.54–12201.55) | 0.39 (0.2–0.58) |
| High-middle SDI | 13802872.4 (10015701.38–18782517.29) | 5044.48 (3660.4–6864.38) | 9613991.68 (6761457.89–13980154.9) | 4163.88 (2928.43–6054.89) | -0.55 (-0.77–0.32) |
| Middle SDI | 39244267.62 (30349922.44–5141560.66) | 6798.91 (5258–8907.89) | 25131493.12 (18758787.41–34018346.37) | 4433.45 (3309.24–6001.18) | -1.18 (-1.42–0.94) |
| Low-middle SDI | 30511271.87 (23968091.43–38516983.06) | 6462.72 (5076.78–8158.44) | 19831243.48 (15055562.13–26336706.5) | 3420.12 (2596.5–4542.05) | -1.79 (-2.04–1.54) |
| Low SDI | 18483100.26 (14807326.06–22907264.27) | 8074.27 (6468.53–10006.95) | 25353300.04 (20262612.56–31672496.86) | 5508.89 (4402.76–6881.95) | -1.18 (-1.29–1.08) |
| Andean Latin America | 2896152.29 (2298925.85–3568555.15) | 19500.04 (15478.86–24027.39) | 1776741.44 (1320290.4–2348039.33) | 9819.07 (7296.52–12976.32) | -2.25 (-2.51–2) |
| Australasia | 588167.88 (497676.91–685,617.72) | 12825.41 (10852.19–14950.37) | 587102.24 (422578.22–795234.33) | 10244.06 (7373.36–13875.66) | -0.89 (-0.95–0.84) |
| Caribbean | 1933705.78 (1571978.31–2328420.16) | 16943.86 (13774.27–20402.5) | 1765928.5 (1488354.9–2113794.02) | 15349.09 (12936.48–18372.67) | -0.3 (-0.38–0.23) |
| Central Asia | 753641.13 (539612.31–1043458.57) | 3015.62 (2159.21–4175.3) | 796272.74 (557427.26–1130159.95) | 2877.14 (2014.13–4083.57) | -0.19 (-0.23–0.15) |
| Central Europe | 1621916.59 (1123512.11–2266547.91) | 5501.08 (3810.63–7687.48) | 1548515.92 (1128122.46–2139161.51) | 8748.08 (6373.14–12084.83) | 1.54 (1.3–1.78) |
| Central Latin America | 6832739.51 (5258975.5–8776158.16) | 10612.94 (8168.49–13631.55) | 3722509.04 (2738613.28–5004862.94) | 5863.61 (4313.8–7883.54) | -1.92 (-2.23–1.6) |
| Central Sub-Saharan Africa | 1586154.57 (1243659.72–1990744.73) | 6269.73 (4915.92–7868.98) | 2344076.58 (1853490.13–2990272.41) | 3994.57 (3158.55–5095.76) | -1.58 (-1.73–1.43) |
| East Asia | 15590486.31 (10996530.07–22313689.74) | 4726.77 (3333.96–6765.13) | 9784272.55 (6689181.73–14658691.86) | 3659.7 (2502.01–5482.92) | -0.66 (-1.23–0.08) |
| Eastern Europe | 2474167.94 (1724874.75–3575083.98) | 4807.76 (3351.75–6947.04) | 1460986.36 (1006080.35–2094765.7) | 4121.95 (2838.5–5910.07) | -0.8 (-0.93–0.68) |
| Eastern Sub-Saharan Africa | 9553549.11 (7613501.3–11760634.77) | 10548.16 (8406.14–12985.03) | 12518543.63 (9944481.11–15406711.76) | 7015.88 (5573.28–8634.52) | -1.36 (-1.44–1.28) |
| High-income Asia Pacific | 2708389.02 (1998530.3–3681545.07) | 7694.39 (5677.72–10459.07) | 1134622.87 (791369.63–1642095.95) | 5059.51 (3528.88–7322.43) | -1.41 (-1.74–1.08) |
| High-income North America | 8278424.89 (6015393.19–11735057.63) | 13422.08 (9752.95–19026.43) | 8843067.72 (6751648.32–11531756.53) | 13476.4 (10289.18–17573.83) | 0.69 (0.42–0.97) |
| North Africa and Middle East | 8857556.28 (6972120.59–11005114.51) | 6304.97 (4962.88–7833.64) | 7751220.78 (5,834,860.98–10,152,189.84) | 4228.2 (3182.85–5537.9) | -1.28 (-1.34–1.22) |
| Oceania | 137268.58 (113178.77–165832.59) | 5122.22 (4223.3–6188.1) | 166,400.08 (138,867.8–197,217.75) | 3275.03 (2733.15–3881.58) | -1.63 (-1.79–1.47) |
| South Asia | 23036407.39 (16999997.68–31030442.12) | 5315.74 (3922.82–7160.4) | 12,434,831.7 (8,720,440.49–17,304,975.1) | 2452.53 (1719.93–3413.07) | -1.69 (-2.21–1.17) |
| Southeast Asia | 10794362.85 (8528649.9–13428722.2) | 6321.83 (4994.89–7864.67) | 7,002,601.79 (5,549,350.82–8,851,332.5) | 4055.87 (3214.15–5126.64) | -1.37 (-1.48–1.27) |
| Southern Latin America | 921879.65 (705391.84–1212392.74) | 6176.15 (4725.79–8122.45) | 981,279.46 (687,088.7–1,422,069.83) | 6769.53 (4740–9810.4) | 0.47 (0.31–0.63) |
| Southern Sub-Saharan Africa | 926241.37 (708721.91–1233666.43) | 4476.9 (3425.54–5962.82) | 641,408.02 (483,865.68–855,705.92) | 2665.22 (2010.59–3555.69) | -2.08 (-2.35–1.8) |
| Tropical Latin America | 9315852.75 (6840060.47–12268012.02) | 17,375.79 (12,757.98–22,882.11) | 5,010,780.07 (3,653,977.17–6,818,515.92) | 9983.02 (7279.85–13584.58) | -1.84 (-2.05–1.63) |
| Western Europe | 4271961.93 (3138205.92–5824460.61) | 6015.3 (4418.87–8201.35) | 3,883,370.6 (2,764,223.31–5,334,178.58) | 5700.92 (4057.97–7830.75) | -0.16 (-0.27–0.04) |
| Western Sub-Saharan Africa | 5798410.43 (4530118.93–7471183.18) | 6598.11 (5154.9–8501.59) | 11,566,653.74 (9,063,378.41–14,937,651.27) | 5385.76 (4220.16–6955.39) | -0.79 (-0.85–0.73) |
Abbreviations: ASR Age-standardized rate, EAPC Estimated annual percentage change, SDI Sociodemographic Index, UI Uncertainty interval
Fig. 1.
Epidemiologic trends of incidence, prevalence, and disability-adjusted life-years rates in 5 sociodemographic index regions of childhood asthma from 1990 to 2021
Among SDI regions, the Low SDI region had the highest burden with 25.3 million cases in 2021. Notable trends included the High SDI region showing the only increase in prevalence (EAPC: 0.39, 95% CI: 0.2 to 0.58), while the Low-middle SDI region demonstrated the largest decline (EAPC: -1.79, 95% CI: -2.04 to -1.54) (Table 1, Fig. 1). A unique pattern emerged in low SDI regions, where the male-to-female prevalence ratio peaked in the 10–14 years age group, differing from other regions.
The global burden of childhood AD reached 72.4 million cases in 2021. The ASPR showed a modest decrease from 1990 to 2021 (from 3,889.74 to 3,600.45 per 100,000 population), with an EAPC of -0.23 (95% CI, -0.25 to -0.21) (Table S1, Figure S3). The 5–9 year age group maintained the highest case numbers throughout the study period (Figure S4), with girls generally showing higher prevalence than boys (Figure S5). The Middle SDI region recorded the highest number of cases (19.7 million) in 2021, while the High SDI region showed the highest ASPR (6,544.18 per 100,000 population). The High-middle SDI region demonstrated the largest increase in prevalence (EAPC: 0.22, 95% CI: 0.11–0.33), while the Low-middle SDI region showed the greatest decline (EAPC: -0.18, 95% CI: -0.18 to -0.17) (Table S1, Figure S3). A distinctive pattern was observed in the low SDI region, where the male-to-female ratio peaked in the 5–9 years age group, contrasting with other regions where the ratio consistently decreased with age (Figure S5).
Incidence
Global childhood asthma incident cases decreased by 17.53% from 28.2 million in 1990 to 23.3 million in 2021. The age-standardized incidence rate (ASIR) showed a 4.17% reduction, declining to 1,155.77 per 100,000 population in 2021 (Table S2). While ASIR declined across all age groups (Figure S6), gender patterns varied by age: males showed higher rates in younger groups (< 10 years), while females had higher rates in the 10–14 years group (Figure S7). The Low SDI region reported the highest incident cases (6.3 million) in 2021, while the High SDI region showed the only increasing trend (EAPC: 0.44, 95% CI: 0.23–0.66) (Table S2, Fig. 1). Notable gender differences emerged across SDI regions: while High, High-middle, and Middle SDI regions showed female predominance in the 10–14 age group, Low-middle and Low SDI regions maintained male predominance across all age groups (Figure S7).
The global incident cases of childhood AD showed a modest increase of 4.77% from 1990 to 2021, though ASIR decreased from 560 to 507.19 per 100,000 population (EAPC: -0.18, 95% CI: -0.23 to -0.14) (Table S3). All age groups showed slight increases in incident cases over this period (Figure S8), with consistently higher rates in females across all age groups (Figure S9). Among SDI regions, the Low-middle SDI region recorded the highest incident cases (2.8 million) in 2021, while the High SDI region showed the highest ASIR (791.94 per 100,000 population). The Low-middle SDI region demonstrated the largest decline in ASIR (EAPC: -0.29). A unique pattern emerged in the Low SDI region, where the male-to-female ASIR ratio increased with age, contrasting with the decreasing ratio observed in other regions, though remaining below 1 across all age groups (Figure S9).
DALYs
Globally, the number of asthma DALYs decreased from 6,937,823.96 (95% UI: 4,886,494.73–9,759,226.38) in 1990 to 4,567,713.52 (95% UI: 3,022,809.17–6,932,991.83) in 2021, with the age-standardized rate decreasing from 398.92 (95% UI: 280.97–561.15) to 227.04 (95% UI: 150.25–344.61) per 100,000 children (TableS4, Fig. 1). The EAPC in the global ASR was -1.63 (95% CI: -1.8 to -1.45) from 1990 to 2021 (TableS4). Globally, the highest male-to-female ASR ratios were found in the 5–9 year age group, followed by the 10–14 year age group, while the lowest male-to-female ASR ratios were found in the < 5 year age group, although the ratios were greater than 1 in all three age groups (Figure S10).
In high SDI region, the number of asthma DALYs decreased from 738,387.01 (95% UI: 454,054.12–1,151,100.96) to 655,413.91 (95% UI: 398,184.45–1,066,045.98), while the ASR remained relatively stable, with an EAPC of 0.19 (95% CI: 0–0.39). High-middle SDI region experienced a decrease in both the number of asthma DALYs (from 682,849.38 [95% UI: 446,484.86–1,025,770.09] to 405,423.46 [95% UI: 233,372.61–673,463.43]) and the ASR (from 249.56 [95% UI: 163.18–374.88] to 175.59 [95% UI: 101.08–291.68] per 100,000 children), with an EAPC of -1.08 (95% CI: -1.31 to -0.86). Middle SDI region also saw a decline in the number of asthma DALYs (from 2,199,484.6 [95% UI: 1,530,907.76–3,174,902.27] to 1,163,825.18 [95% UI: 739,511.92–1,841,826.8]) and the ASR (from 381.05 [95% UI: 265.22–550.04] to 205.31 [95% UI: 130.46–324.92] per 100,000 children), with an EAPC of -1.74 (95% CI: -1.99 to -1.49). Low-middle SDI region experienced a decrease in the number of asthma DALYs (from 1,965,155.78 [95% UI: 1,422,596.78–2,696,345.49] to 981,267.46 [95% UI: 657,912.38–1,464,892.12]) and the ASR (from 416.25 [95% UI: 301.33–571.12] to 169.23 [95% UI: 113.46–252.64] per 100,000 children), with an EAPC of -2.72 (95% CI: -2.91 to -2.53). Low SDI region saw an increase in the number of asthma DALYs (from 1,343,585.45 [95% UI: 954,626.48–1,793,696.43] to 1,355,380.59 [95% UI: 951,389–1,932,480.3]), but a decrease in the ASR (from 586.94 [95% UI: 417.03–783.57] to 294.5 [95% UI: 206.72–419.9] per 100,000 children), with an EAPC of -2.16 (95% CI: -2.24 to -2.08).
In most SDI areas, the male-to-female ASR ratios is greater than 1, while in Low SDI areas for age groups younger than 5 years, the male to female ratio is less than 1 (Figure S10).
Globally, the number of AD DALYs increased from 2,988,889.97 (95% UI: 1,535,008.01–5,018,449.49) in 1990 to 3,209,162.1 (95% UI: 1,642,150.47–5,373,422.39) in 2021, while the ASR decreased from 171.86 (95% UI: 88.26–288.56) to 159.51 (95% UI: 81.62–267.09) per 100,000 children, with an EAPC of -0.22 (95% CI: -0.24 to -0.19) (TableS4). In 2021, the Middle SDI region had the highest number of AD-associated DALYs (873,274.31; 95% UI, 448,788.16–1,466,681.79). The Low-middle SDI region had the greatest decrease (EAPC:-0.15,95%CI:-0.16 to -0.15) in the ASR of AD-associated DALYs (Table S4).
Geographic regional trends
Prevalence
Among the 21 geographic regions in 2021, Eastern Sub-Saharan Africa reported the highest number of childhood asthma cases (12.5 million), while the Caribbean showed the highest ASPR (15,349.09 per 100,000 population). In contrast, Oceania had the lowest case numbers (166,400) and South Asia the lowest ASPR (2,452.53 per 100,000 population). The most notable temporal trend was observed in Central Europe, showing the largest increase in prevalence (EAPC: 1.54, 95% CI: 1.3–1.78). The relationship between SDI and ASPR showed a unique pattern, with a negative correlation at SDI values below 0.4 and a positive correlation above 0.4 (Figure S11).
For AD in 2021, South Asia carried the highest burden with 787,933 cases, while Central Asia showed the highest ASPR (466.58 per 100,000 population). Oceania reported the lowest case numbers (8,423) and Eastern Sub-Saharan Africa the lowest ASPR (93.26 per 100,000 population). Eastern Europe demonstrated the most significant increase in prevalence from 1990 to 2021 (EAPC: 0.54, 95% CI: 0.33–0.74). Unlike asthma, AD showed a consistent positive correlation between ASPR and SDI levels (Figure S11).
Incidence
In 2021, the geographical distribution of childhood asthma incidence showed marked variations, with South Asia reporting the highest number of incident cases (3.2 million) but the lowest ASIR (631.18 per 100,000 population). In contrast, High-income North America demonstrated the highest ASIR (3,192.52 per 100,000 population), while Oceania had the lowest number of incident cases (44,481). Notable temporal trends included Central Europe’s significant increase in incidence (EAPC: 1.64, 95% CI: 1.41–1.87) and Southern Sub-Saharan Africa’s substantial decrease (EAPC: -1.93, 95% CI: -2.19 to -1.66). The relationship between ASIR and SDI mirrored the prevalence pattern, showing a negative correlation at lower SDI values followed by a positive correlation at higher values (Figure S11).
For AD incidence in 2021, Eastern Europe recorded the highest number of new cases (163,477), with Central Asia showing the highest ASIR (1,141.33 per 100,000 population). Western Sub-Saharan Africa reported the lowest ASIR (345.52 per 100,000 population), while Oceania had the lowest incident cases (30,766). The most significant temporal changes were observed in Eastern Europe, showing the largest increase (EAPC: 0.88, 95% CI: 0.53–1.24), while South Asia experienced the most substantial decrease (EAPC: -0.25). Unlike asthma, AD showed a consistent positive correlation between ASIR and increasing SDI levels (Figure S11).
DALYs
In 2021, Eastern Sub-Saharan Africa had the highest number of childhood asthma-associated DALYs (665,369.56; 95% UI, 465,752.72–967,993.54), whereas Oceania had the lowest number (13,091.82; 95% UI, 9129.58–17,313.35). Caribbean had the highest DALYs rate (823.21; 95% UI, 559.18–1171.79); South Asia had the lowest DALYs rate (114.29; 95% UI, 72.26–176.59). From 1990 to 2021, Western Europe had the smallest decrease in the DALYs rate (EAPC, -0.3; 95% CI, -0.42–0.18); Andean Latin America had the largest decrease (EAPC, -3.35; 95% CI, -3.74–2.97).
Based on the 2021 GBD data, the significant contributors to the DALYs of AD are South Asia (787,933.12; 95% UI, 402,962.49–1,312,398.18) and East Asia (354,096.16; 95% UI, 182,355.36–594,617.43). Caribbean had the highest DALYs rate (823.21; 95% UI, 559.18–1171.79); Central Asia had the lowest DALYs rate (466.58; 95% UI, 237.61–795.04). From 1990 to 2021, Eastern Europe had the largest increase in the DALYs rate (EAPC,0.54; 95% CI, 0.33–0.74); High-income North America had the largest decrease (EAPC, -0.17; 95% CI,-0.2–0.13).
National trends
Prevalence
In 2021, China reported the highest absolute number of childhood asthma cases (9.4 million), while Haiti showed the highest ASPR (23,051 per 100,000 population) among 204 countries (Fig. 2, Table S5). Temporal trends revealed significant variations: Poland demonstrated the largest increase in prevalence (EAPC: 3.03%), while Guatemala showed the steepest decline (EAPC: -3.41%). Notable changes from 1990 to 2021 included substantial increases in Qatar (255.85%) and Chad (173.63%), contrasting with marked decreases in Japan (61.65%) and Niue (64.15%) (Fig. 3). The global mean prevalence in 2021 was 4,757.84 per 100,000 population, with an equal distribution of countries above and below this average (102 countries each) (Fig. 4). For AD in 2021, India led with the highest case count (12.9 million), followed by China (7.6 million) and the United States (3.3 million). Mongolia recorded the highest ASPR (10,668 per 100,000 population) (Fig. 2, Table S6). The Russian Federation showed the most significant increase in prevalence (EAPC: 0.50%), while the United States experienced the largest decrease (EAPC: -0.18%). Between 1990 and 2021, Qatar (296.69%) and Afghanistan (236.21%) saw the largest increases, while Albania (61.18%) and Moldova (59.63%) showed the steepest declines (Figure S12). The global mean prevalence was 3,600.45 per 100,000 population in 2021, with 112 countries above and 92 countries below this average.
Fig.2.
The global disease burden of allergic diseases in children for both sexes in 204 countries and territories
Fig. 3.
Change prevalence cases of asthma in children in 204 countries and territories from 1990 to 2021
Fig. 4.
Association between age-standardized asthma in children prevalence rate and sociodemographic index
Incidence
In 2021, India reported the highest number of new childhood asthma cases (2.4 million), while Haiti demonstrated the highest incidence rate (4,421.6 per 100,000 population) among 204 countries (Fig. 2, Table S7). Temporal trends showed the Maldives experiencing the largest increase in incidence (EAPC: 3.03), while the Republic of Moldova had the steepest decline (EAPC: -3.41). The global mean incidence was 1,155.77 per 100,000 population, with 96 countries reporting above and 108 countries below this average (Table S7). For AD in 2021, India maintained the highest number of incident cases (1.9 million), while Uzbekistan showed the highest incidence rate (1,185.2 per 100,000 population) (Fig. 2, Table S7). The Russian Federation demonstrated the most substantial increase in incidence (EAPC: 1.02), contrasting with the Northern Mariana Islands which showed the largest decrease (EAPC: -0.79). The global mean incidence was 507.19 per 100,000 population, with 118 countries above and 86 countries below this average (Table S7).
DALYs
In 2021, India had the highest number of asthma-associated childhood DALYs (425,585; 95% UI, 263,060.6–664,492.1). (Fig. 2 and Table S8). Haiti had the highest rate of childhood asthma-associated DALYs (1383.2; 95% UI, 920.8–1923.1) (Fig. 2 and Table S8). Poland (EAPC, 2.95; 95% CI, 2.48–3.42) had the greatest increase in DALYs rate; Guatemala (EAPC, -5.69; 95% CI, -6.49 to -4.88)) and Egypt (EAPC, -4.84; 95% CI, -5.31 to -4.37)) had the greatest decreases (Table S8). In 2021, India had the highest number of AD-associated childhood DALYs (568,208.3; 95% UI, 290,240.1–944,065.1). (Fig. 2 and Table S8). Japan had the highest rate of childhood AD-associated DALYs (473.9; 95% UI, 238.7–794.3)(Fig. 2 and Table S8). Russian Federation (EAPC, 0.51; 95% CI, 0.29–0.72) had the greatest increase in DALYs rate; United States of America (EAPC, -0.18; 95% CI, -0.22 to -0.14) and United Kingdom (EAPC,-0.13; 95% CI, -0.19 to -0.06) had the greatest decreases (Table S8).
Risk factors for asthma in children
Asthma-related DALYs and deaths attributable to three risk factors—all risk factors, metabolic risks, and environmental/occupational risks—as classified in the GBD study 2021, were collected and stratified by region. Environmental/occupational risks accounted for 3.2% of childhood asthma-associated DALYs worldwide, while metabolic risks caused 7.5% of childhood asthma-associated DALYs and 5.1% of childhood asthma-associated deaths globally. Among the 21 geographical regions, the proportion of asthma-associated DALYs attributable to all risk factors ranged from 6.1% in Southeast Asia to 17.7% in Southern Latin America (Fig. 5). In 2021, all risk factors contributed to 5.1% of childhood asthma-associated deaths worldwide, with the highest proportion (13.6%) observed in High-income North America and the lowest (3.2%) in South Asia. Metabolic risks were responsible for 5.1% of childhood asthma-associated deaths globally, with the highest proportion (13.6%) in High-income North America and the lowest (3.2%) in South Asia. In general, metabolic risks accounted for a higher proportion of asthma-associated DALYs compared to environmental/occupational risks.
Fig. 5.
Proportion of childhood asthma deaths and disability-adjusted life-years attributable to risk factors
Key findings summary
For childhood asthma, the global prevalence reached 95.7 million cases in 2021, with an age-standardized prevalence rate of 4,757.84 per 100,000 population. The global burden showed a significant decline, with the age-standardized prevalence rate decreasing by 30.4% from 1990 to 2021 (EAPC: -0.97). The Low SDI region bore the highest burden with 25.4 million cases in 2021. The disease demonstrated clear age and gender patterns, with peak prevalence observed in the 5–9 years age group and higher rates among boys compared to girls. The global health impact of childhood asthma has improved over time, as evidenced by the decrease in DALYs from 6.9 million in 1990 to 4.6 million in 2021.
For atopic dermatitis, the global prevalence was 72.4 million cases in 2021, with an age-standardized prevalence rate of 3,600.45 per 100,000 population. The disease burden showed a modest decline from 1990 to 2021 (EAPC: -0.23). Unlike asthma, the Middle SDI region recorded the highest burden with 19.7 million cases in 2021. The disease displayed distinct demographic patterns, with peak prevalence in the 0–5 years age group and higher rates among girls compared to boys. Notably, the High SDI region demonstrated the highest age-standardized prevalence rate at 6,544.18 per 100,000 population in 2021.
Discussion
Allergic disorders in children has progressively become a serious public health problem worldwide. In this study, we comprehensively analyzed the global, regional, and national burden of childhood allergic diseases, specifically asthma and AD, from 1990 to 2021 using data from the GBD 2021. Our findings reveal that the global prevalence, incidence, and DALYs of childhood asthma and AD have undergone significant changes over the past three decades, with varying trends across different age groups, sexes, and SDI regions.
The global prevalence of childhood asthma decreased by 30.4% from 1990 to 2021, with the ASPR declining from 6835.37 per 100,000 population in 1990 to 4757.84 per 100,000 population in 2021. This declining trend aligns with findings from several multi-regional studies. The International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three study reported varying trends across regions, with decreasing prevalence in several previously high-prevalence areas [19]. Similar patterns were observed in a worldwide time-trends analysis of asthma prevalence [20], while the GBD highlighted regional variations in childhood asthma trends [21]. A systematic review of worldwide childhood asthma epidemiology also documented this heterogeneous pattern of decline, particularly notable in regions that historically reported high prevalence rates [22]. The High SDI region experienced the most significant increase in the prevalence of childhood asthma, with an EAPC of 0.39, while the Low-middle SDI region observed the largest decline, with an EAPC of -1.79. In terms of geographic regional trends, the prevalence of childhood asthma varied considerably across the 21 GBD regions in 2021. The highest prevalence was observed in the High-income North America region, followed by the Caribbean and Australasia regions. In contrast, the lowest prevalence was found in the Eastern Sub-Saharan Africa and Central Sub-Saharan Africa regions.
The marked regional variations in childhood asthma prevalence reflect a complex interplay of multiple factors. In High-income North America, the elevated prevalence of childhood asthma can be attributed to several region-specific factors. First, the high degree of urbanization and industrialization has led to increased exposure to traffic-related air pollution, with studies showing that children living within 75 m of major roadways have a 29% higher risk of asthma development [23]. Second, the widespread adoption of ‘Western lifestyle’ factors, including reduced outdoor activity (average of only 30 min per day compared to 2 h in many European countries) [24], high rates of obesity (affecting 19.7% of U.S. children), and increased indoor allergen exposure due to tighter building insulation and greater time spent indoors [25], has created an environment conducive to asthma development. Additionally, the region’s unique allergenic plant species, particularly ragweed which is more prevalent in North America than other continents, contributes to higher sensitization rates [26]. The interaction of these environmental factors with genetic susceptibility, particularly variants in the 17q21 locus which are more common in populations of European descent, further amplifies asthma risk in this region [27]. Conversely, the lower prevalence observed in Sub-Saharan Africa likely results from a multifaceted interaction between environmental, socioeconomic, and biological factors. Beyond the previously noted lower industrialization levels, research has identified protective effects of helminth infections [28], different patterns of microbial exposure [29], and distinct genetic factors [30]. However, it’s important to note that prevalence data in this region may be influenced by underdiagnosis due to limited healthcare access and different diagnostic practice [31]. Additionally, emerging evidence suggests that rapid urbanization in certain African regions is associated with increasing asthma rates, particularly in urban centers [32].
In contrast to asthma, the global prevalence of childhood AD remained relatively stable from 1990 to 2021, with a slight decrease in the ASPR from 3889.74 per 100,000 population in 1990 to 3600.45 per 100,000 population in 2021. Similarly, the prevalence of childhood AD also varied across geographic regions in 2021. The highest prevalence was observed in the Western Europe region, followed by the High-income North America and Australasia regions. These regional differences may be influenced by factors such as climate, hygiene practices, and genetic susceptibility [33, 34]. For instance, the high prevalence of AD in Western Europe may be related to a combination of cold weather, low humidity, and a high level of hygiene [35, 36], while the low prevalence in Oceania and Southeast Asia may be due to a warmer climate and a lower level of industrialization [37]. Our study also revealed significant age and sex differences in the prevalence of childhood asthma and AD. In 2021, the ASPR of asthma was generally higher in boys than in girls, with a peak prevalence among children aged 5 to 9 years. The sex difference in asthma prevalence may be attributed to factors such as differences in lung development, immune responses, and hormonal influences between boys and girls.
The global incidence of childhood asthma decreased by 17.53% from 1990 to 2021, with the ASIR declining from 1621.27 per 100,000 population in 1990 to 1155.77 per 100,000 population in 2021. However, the trends in asthma incidence also varied across different SDI regions, with the High SDI region experiencing the greatest increase (EAPC: 0.44) and the Low-middle SDI region observing the largest decline (EAPC: -0.29). Similarly, the global incidence of childhood AD decreased by 4.77% from 1990 to 2021, with the ASIR declining from 560 per 100,000 population in 1990 to 507.19 per 100,000 population in 2021. The Low-middle SDI region experiencing the largest decline (EAPC: -0.29) and the High SDI region having the highest ASIR in 2021 (791.94 per 100,000 population). The incidence of childhood asthma and AD also varied across geographic regions in 2021. For asthma, the highest incidence was observed in the High-income North America region, while the lowest incidence was found in the Eastern Sub-Saharan Africa region. For AD, the highest incidence was observed in the Western Europe region, while the lowest incidence was found in the Oceania region. The number of asthma-related DALYs decreased by 34.16% from 1990 to 2021, with the age-standardized rate declining from 398.92 to 227.04 per 100,000 children. In contrast, the number of AD-related DALYs increased by 7.36% from 1990 to 2021, despite a decrease in the age-standardized rate from 171.86 to 159.51 per 100,000 children. Regarding asthma, the most substantial impact was noted in the High-income North America region, while Eastern Sub-Saharan Africa experienced the least severe effects. In contrast, AD presented its most significant burden in Western Europe, with Oceania showing the lowest rates.
These disparities can be attributed to various factors. A primary contributor may be the implementation of crucial guidelines, such as those promulgated by the National Heart, Lung, and Blood Institute in 1991 and the Global Initiative for Asthma in 1995. These protocols likely exerted considerable influence on disease management and outcomes [38, 39]. These protocols, in conjunction with heightened global consciousness and enhanced asthma care strategies, have likely played a pivotal role in the observed decline. Moreover, the innovation and widespread adoption of diverse therapeutic approaches have been crucial in this trend. The reduction can also be attributed to the superior healthcare infrastructure available in regions boasting higher SDI scores. For instance, while countries like Haiti and the Central African Republic exhibited the highest asthma-related mortality rates, nations such as Armenia, Taiwan, and Finland reported significantly lower figures. This disparity underscores how advanced medical services facilitate early identification of allergic disorders in pediatric populations, enabling more efficacious treatment regimens.
The correlation between healthcare quality, particularly in high-SDI areas, and the successful management of these conditions is evident. Despite the marked global and regional disparities in incidence and mortality rates, it remains imperative to redouble efforts aimed at enhancing asthma prevention and control, especially in resource-constrained environments. The heterogeneity in prevalence, incidence, and burden of childhood asthma and atopic dermatitis across geographical zones accentuates the necessity for tailored, region-specific interventions and policies that address the unique challenges and opportunities inherent to each area.
As an illustration, in regions exhibiting high prevalence and incidence of asthma, such as High-income North America and the Caribbean, targeted initiatives focusing on mitigating air pollution, promoting salubrious lifestyles, and improving healthcare accessibility could prove particularly efficacious [40]. In regions with high prevalence and incidence of AD, such as Western Europe and High-income North America, interventions that focus on improving skin care, reducing exposure to allergens and irritants, and managing symptoms may be more appropriate [41]. In addition to region-specific interventions, our findings also highlight the importance of global efforts to reduce the burden of childhood allergic diseases. While evidence-based guidelines such as GINA have played a role in improving asthma management and outcomes, the global decline in asthma prevalence likely reflects a complex interplay of multiple factors. These may include changes in environmental exposures [42], improved early-life interventions [43], enhanced understanding of disease mechanisms [44], and evolving diagnostic practices [45]. The continued strengthening of healthcare systems, promotion of research, and global collaboration remain important for addressing childhood asthma burden. However, future research should focus on better understanding the multifaceted drivers of changing asthma prevalence patterns to inform more targeted preventive strategies [46].
Limitations
Our study, however, is not without its limitations. Firstly, it’s crucial to acknowledge the inherent constraints of GBD research. Firstly, the quality and availability of data vary significantly across different countries and regions. Many low- and middle-income countries lack robust disease surveillance systems and standardized diagnostic criteria for allergic conditions, which may lead to an underestimation or inaccurate representation of the true burden of asthma and atopic dermatitis in these areas. This data gap is particularly pronounced in rural regions and areas with limited healthcare infrastructure, where access to allergists and specialized diagnostic facilities is restricted. Furthermore, variations in diagnostic practices and disease definitions across different healthcare settings could affect the accuracy of reported cases, potentially skewing our global estimates. Secondly, the absence of comprehensive registry systems in many countries for recording mortality is another limitation. This lack often results in an underestimation of the actual figures. Lastly, despite the multiple methodologies employed in GBD studies to perform calculations, rectify disease classification errors, and reclassify ambiguous codes, potential inaccuracies within the data cannot be overlooked. These inherent inaccuracies can impact the reliability of our findings.
Conclusions
Our study presents a comprehensive analysis of geographic and regional trends in childhood asthma and AD prevalence, incidence, and burden from 1990 to 2021. We observed significant variations across regions, with distinct patterns of change over the study period. While our findings describe these epidemiological patterns, the complex factors underlying these trends warrant further investigation. Future research should focus on identifying and analyzing specific risk factors, evaluating existing interventions, and conducting prospective studies to better understand the dynamic nature of these conditions across different geographic contexts. Such research could inform the development of evidence-based strategies to address the continuing burden of childhood allergic diseases.
Supplementary Information
Acknowledgements
No matter the old village doctors who are going to retire or the young who just set foot on the job, they have no regrets, no conditions and actively participated in the front-line work of epidemic prevention and control in China.
Abbreviations
- AD
Atopic Dermatitis
- DALYs
Disability-Adjusted Life Years
- GBD
Global Burden of Disease
- SDI
Socio-Demographic Index
- EAPC
Estimated Annual Percentage Changes
- ASR
Age-Standardized Rate
- CI
Confidence Interval
- UI
Uncertainty Intervals
Authors’ contributions
All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; agreed to submit to the current journal; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.
Funding
There is no funding support in this study.
Data availability
GBD study 2021 data resources were available online from the Global Health Data Exchange (GHDx) query tool (http://ghdx.healthdata.org/gbd-results-tool).
Declarations
Ethics approval and consent to participate
This study is based on data from the Global Burden of Disease (GBD) study. The GBD study uses deidentified data, and a waiver of informed consent was approved by the University of Washington Institutional Review Board. As our research utilized this publicly available, deidentified dataset, additional ethics approval for our specific analysis was not required. This approach is in line with the ethical guidelines for secondary data analysis.
Consent for publication
Not Applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Jun Zheng, Yi-jing Jin and Cheng-hai Wang share co-first authorship.
Contributor Information
Xin-yuan Lai, Email: 24745875368@qq.com.
Shu-qing Hua, Email: shuqinghua@proton.me.
Jia-hui Tai, Email: jhtai96@163.com.
References
- 1.Pearce N, Sunyer J, Cheng S, et al. Comparison of asthma prevalence in the ISAAC and the ECRHS. ISAAC Steering Committee and the European Community Respiratory Health Survey. Int Stud Asthma Allergies Childhood. 2000;16:420–426. [DOI] [PubMed]
- 2.Alavinezhad A, Boskabady MH. The prevalence of asthma and related symptoms in Middle East countries. Clin Respir J. 2018;12(3):865–77. [DOI] [PubMed] [Google Scholar]
- 3.Koo MJ, Kwon R, Lee SW, Choi YS, Shin YH, Rhee SY, Min C, Cho SH, Turner S, Kim SY, Lee J, Yeo SG, Abuabara K, Lee YJ, Shin JI, Kim JH, Shin JU, Yon DK, Papadopoulos NG. National trends in the prevalence of allergic diseases among Korean adolescents before and during COVID-19, 2009–2021: A serial analysis of the national representative study. Allergy. 2023;78(6):1665–70. [DOI] [PubMed]
- 4.Gilaberte Y, Pérez-Gilaberte JB, Poblador-Plou B, Bliek-Bueno K, Gimeno-Miguel A, Prados-Torres A. Prevalence and Comorbidity of Atopic Dermatitis in Children: A Large-Scale Population Study Based on Real-World Data. J Clin Med. 2020;9(6):1632. [DOI] [PMC free article] [PubMed]
- 5.Dharmage SC, Lowe AJ, Matheson MC, et al. Atopic dermatitis and the atopic march revisited. Allergy. 2014;69(1):17–27. [DOI] [PubMed] [Google Scholar]
- 6.Belgrave DCM, Simpson A, Buchan IE, et al. Atopic Dermatitis and Respiratory Allergy: What is the Link. Current dermatology reports. 2015;4(4):221–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Tan RA, Corren J. The relationship of rhinitis and asthma, sinusitis, food allergy, and eczema. Immunol Allergy Clin North Am. 2011;31(3):481–91. [DOI] [PubMed] [Google Scholar]
- 8.Nurmagambetov T, Kuwahara R, Garbe P. The Economic Burden of Asthma in the United States, 2008–2013. Ann Am Thoracic Soc. 2018;15(3):348–356. [DOI] [PubMed]
- 9.Drucker AM, Wang AR, Li W, et al. The Burden of Atopic Dermatitis: Summary of a Report for the National Eczema Association. J Invest Dermatol. 2017;137(1):26–30. [DOI] [PubMed] [Google Scholar]
- 10.Hsu J, Qin X, Beavers S F, et al. Asthma-Related School Absenteeism, Morbidity, and Modifiable Factors. Am J Prev Med. 2016;51(1):23–32. [DOI] [PMC free article] [PubMed]
- 11.Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050: a systematic analysis for the Global Burden of Disease Study 2021. Lancet (London, England). 2023;402(10397):203–234. [DOI] [PMC free article] [PubMed]
- 12.Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet (London, England). 2024;403(10440):2162–2203. [DOI] [PMC free article] [PubMed]
- 13.Shin YH, Hwang J, Kwon R, et al. Global, regional, and national burden of allergic disorders and their risk factors in 204 countries and territories, from 1990 to 2019: A systematic analysis for the Global Burden of Disease Study 2019. Allergy. 2023;78(8):2232–54. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Mathew G, Agha R, Albrecht J, et al. STROCSS 2021: Strengthening the reporting of cohort, cross-sectional and case-control studies in surgery. International journal of surgery (London, England). 2021;96: 106165. [DOI] [PubMed] [Google Scholar]
- 15.Yang JM, Koh HY, Moon SY, et al. Allergic disorders and susceptibility to and severity of COVID-19: A nationwide cohort study. J Allergy Clin Immunol. 2020;146(4):790–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Laughter MR, Maymone MBC, Mashayekhi S, et al. The global burden of atopic dermatitis: lessons from the Global Burden of Disease Study 1990–2017. Br J Dermatol. 2021;184(2):304–9. [DOI] [PubMed] [Google Scholar]
- 17.Molassiotis A, Kwok SWH, Leung AYM, et al. Associations between sociodemographic factors, health spending, disease burden, and life expectancy of older adults (70 + years old) in 22 countries in the Western Pacific Region, 1995–2019: estimates from the Global Burden of Disease (GBD) Study 2019. GeroScience. 2022;44(2):925–51. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet (London, England). 2015;385(9963):117–171. [DOI] [PMC free article] [PubMed]
- 19.Pearce N, Aït-Khaled N, Beasley R, et al. Worldwide trends in the prevalence of asthma symptoms: phase III of the International Study of Asthma and Allergies in Childhood (ISAAC). Thorax. 2007;62(9):758–66. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Asher MI, García-Marcos L, Pearce NE, Strachan DP. Trends in worldwide asthma prevalence. Eur Respir J. 2020;56(6):2002094. [DOI] [PubMed]
- 21.Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet (London, England). 2020;396(10258):1204–1222. [DOI] [PMC free article] [PubMed]
- 22.Lai CKW, Beasley R, Crane J, et al. Global variation in the prevalence and severity of asthma symptoms: phase three of the International Study of Asthma and Allergies in Childhood (ISAAC). Thorax. 2009;64(6):476–83. [DOI] [PubMed] [Google Scholar]
- 23.McConnell R, Islam T, Shankardass K, et al. Childhood incident asthma and traffic-related air pollution at home and school. Environ Health Perspect. 2010;118(7):1021–6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Larouche R, Garriguet D, Tremblay MS. Outdoor time, physical activity and sedentary time among young children: The 2012–2013 Canadian Health Measures Survey. Can J Public Health = Revue canadienne de sante Publique. 2017;107(6):e500-e506. [DOI] [PMC free article] [PubMed]
- 25.Hauptman M, Phipatanakul W. The school environment and asthma in childhood. Asthma Res Pract. 2015;1:12. [DOI] [PMC free article] [PubMed]
- 26.Ziska LH, Makra L, Harry SK, et al. Temperature-related changes in airborne allergenic pollen abundance and seasonality across the northern hemisphere: a retrospective data analysis. The Lancet Planetary health. 2019;3(3):e124–31. [DOI] [PubMed] [Google Scholar]
- 27.Vicente CT, Revez J A, Ferreira MAR. Lessons from ten years of genome-wide association studies of asthma. Clin Transl Immunol. 2017;6(12):e165. [DOI] [PMC free article] [PubMed]
- 28.Arrais M, Maricoto T, Nwaru BI, et al. Helminth infections and allergic diseases: Systematic review and meta-analysis of the global literature. J Allergy Clin Immunol. 2022;149(6):2139–52. [DOI] [PubMed] [Google Scholar]
- 29.Ege MJ, Mayer M, Normand A, et al. Exposure to environmental microorganisms and childhood asthma. N Engl J Med. 2011;364(8):701–709. [DOI] [PubMed]
- 30.Custovic A, Marinho S, Simpson A. Gene-environment interactions in the development of asthma and atopy. Expert rev respir med. 2012;6(3):301–308. [DOI] [PubMed]
- 31.Nafti S, Taright S, El Ftouh M, et al. Prevalence of asthma in North Africa: the Asthma Insights and Reality in the Maghreb (AIRMAG) study. Respir Med. 2009;103(Suppl 2):S2–11. [DOI] [PubMed] [Google Scholar]
- 32.Morgan BW, Siddharthan T, Grigsby MR, et al. Asthma and Allergic Disorders in Uganda: A Population-Based Study Across Urban and Rural Settings. The journal of allergy and clinical immunology. In practice. 2018;6(5):1580–1587. [DOI] [PMC free article] [PubMed]
- 33.Weidinger S, Novak N. Atopic dermatitis. Lancet (London, England). 2016;387(10023):1109–22. [DOI] [PubMed] [Google Scholar]
- 34.Deckers IAG, McLean S, Linssen S, et al. Investigating international time trends in the incidence and prevalence of atopic eczema 1990–2010: a systematic review of epidemiological studies. PLoS ONE. 2012;7(7): e39803. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Silverberg JI, Hanifin J, Simpson EL. Climatic factors are associated with childhood eczema prevalence in the United States. J Invest Dermatol. 2013;133(7):1752–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Engebretsen KA, Bager P, Wohlfahrt J, et al. Prevalence of atopic dermatitis in infants by domestic water hardness and season of birth: Cohort study. J Allergy Clin Immunol. 2017;139(5):1568–74. [DOI] [PubMed] [Google Scholar]
- 37.Tham EH, Leung DY. Mechanisms by Which Atopic Dermatitis Predisposes to Food Allergy and the Atopic March. Allergy, Asthma Immunol Res. 2019;11(1):4–15. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Shin YH, Lee SW, Yon DK. Single Inhaler as Maintenance and Reliever Therapy (SMART) in Childhood Asthma in 2021: The Paradigm Shift in the Inhaled Corticosteroids Reliever Therapy Era. 2021;9:3819–3820. [DOI] [PubMed]
- 39.Cloutier MM, Baptist AP, Blake KV, et al. 2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group. J Allergy Clin Immunol. 2020;146(6):1217–70. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40.Guarnieri M, Balmes JR. Outdoor air pollution and asthma. Lancet (London, England). 2014;383(9928):1581–92. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41.Boguniewicz M, Fonacier L, Guttman-Yassky E, et al. Atopic dermatitis yardstick: Practical recommendations for an evolving therapeutic landscape. Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology. 2018;120(1):10–22. [DOI] [PubMed] [Google Scholar]
- 42.Miller RL, Grayson MH, Strothman K. Advances in asthma: New understandings of asthma’s natural history, risk factors, underlying mechanisms, and clinical management. J Allergy Clin Immunol. 2021;148(6):1430–41. [DOI] [PubMed] [Google Scholar]
- 43.Danov Z, Guilbert TW. Prevention of asthma in childhood. Curr Opin Allergy Clin Immunol. 2007;7(2):174–9. [DOI] [PubMed] [Google Scholar]
- 44.Dharmage SC, Perret JL, Custovic A. Epidemiology of Asthma in Children and Adults. Front Pediatr. 2019;7:246. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Pavord ID, Beasley R, Agusti A, et al. After asthma: redefining airways diseases. Lancet (London, England). 2018;391(10118):350–400. [DOI] [PubMed] [Google Scholar]
- 46.Agustí A, Bafadhel M, Beasley R, Bel EH, Faner R, Gibson PG, Louis R, McDonald VM, Sterk PJ, Thomas M, Vogelmeier C, Pavord ID; on behalf of all participants in the seminar. Precision medicine in airway diseases: moving to clinical practice. Eur respir J. 2017;50(4):1701655. [DOI] [PubMed]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
GBD study 2021 data resources were available online from the Global Health Data Exchange (GHDx) query tool (http://ghdx.healthdata.org/gbd-results-tool).