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Updated May 2026·Annual review cycle

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Quick Answer

Seasonal allergic rhinitis affects ~26% of US adults and 5.2 million US children. Globally, allergic rhinitis affects an estimated 400 million people. The North American pollen season extended ~20 days between 1990 and 2018, with pollen concentrations rising 21%. The annual US economic burden exceeds $11 billion in direct costs alone.

Key Statistics at a Glance

~26%of US adults have seasonal allergic rhinitis (CDC NHIS 2021)
5.2MUS children diagnosed with hay fever (CDC 2021)
400Mpeople globally affected by allergic rhinitis (WAO)
~20 dayspollen season extended in North America 1990–2018 (PNAS 2021)
+21%increase in pollen concentrations 1990–2018 (PNAS 2021)
>$11Bestimated annual US economic burden of allergic rhinitis (AAAAI)
~3.5Mworkdays lost annually in the US to seasonal allergies
20–50%of rhinitis patients also have asthma comorbidity

Prevalence by Country and Region

Country / RegionEstimated PrevalenceNotes
United States~26% adults, ~7% childrenCDC NHIS 2021
United Kingdom~20–30%NHS/UK Biobank estimates
Australia~18–20%AIHW/Australian allergy surveys
Germany~15%German Environmental Survey (GerES)
Japan~20–40% (sugi/pollen specific)High cedar pollen exposure; rapidly rising
Sub-Saharan Africa~5–10% and risingData limited; urbanization-linked increase
South America10–20% (varies by country)ISAAC Phase III data
Global (all rhinitis)~400 million (WAO)Includes seasonal and perennial

Trend Analysis: Pollen Season Extension and Climate

The 2021 Pollen seasons and climate change study published in the Proceedings of the National Academy of Sciences is the most comprehensive analysis of North American pollen trends to date. Using data from 60 pollen monitoring stations spanning 1990–2018, the authors found: season start advanced by ~0.9 days per year, season end was delayed by ~0.3–0.6 days per year, and total annual pollen load increased by 21%. Warming temperatures accounted for ~50% of the observed pollen season changes.

This trend is projected to continue under current climate trajectories. Models suggest pollen seasons could extend by an additional 20–40 days by 2100 under moderate warming scenarios, with 40–50% higher pollen concentrations — representing a substantially higher disease burden for the hundreds of millions affected. Regional breakdown of these trends is explored in our seasonal allergy regions guide.

Healthcare Utilization Data

MetricEstimateSource
Annual physician office visits — rhinitis (US)~17 millionCDC/AAAAI estimates
Annual prescription fills — rhinitis medications (US)>100 million[Source: pharmacy claims data — verify with IQVIA/AARC data]
Annual OTC antihistamine spend — rhinitis (US)>$2 billion[Source: Nielsen/market research — verify with primary data]
Adults reporting work impairment from seasonal allergies~40% of sufferersPatient survey data (AAAAI)
Students missing school days due to seasonal allergies~2 million school days/yearCDC estimate
% who use OTC-only management (never see physician)~50–60%Self-management studies

What the Data Means

Several implications emerge from the seasonal allergy data. First, the sheer scale — affecting roughly 1 in 4 American adults — makes this among the most prevalent chronic conditions in the US, yet it is frequently undertreated. Studies consistently show that fewer than 40% of seasonal rhinitis sufferers seek medical care; the majority rely entirely on OTC medications, which may not adequately address the inflammatory component that underlies congestion.

Second, the productivity impact is significant. Presenteeism studies — measuring reduced productivity while at work rather than absenteeism — consistently show that allergic rhinitis reduces cognitive performance, concentration, and task completion during peak pollen periods. A meta-analysis estimated productivity losses equivalent to 8–12% of working capacity during peak exposure days.

Third, climate-linked pollen increases will disproportionately affect populations in regions where pollen seasons are most lengthening — particularly the upper Midwest, Northeast US, and parts of Central Europe. Future healthcare system planning should account for an increasing rhinitis burden. See our global allergy statistics and research center for the latest findings.

Data Sources & Methodology Note

Primary sources: CDC National Health Interview Survey (NHIS) 2021; Anderegg WRL et al., "Anthropogenic climate change is worsening North American pollen seasons," PNAS 2021; World Allergy Organization (WAO) White Book on Allergy 2013/2020; AAAAI 2022 Allergy Statistics; Blaiss MS et al., AIJAIS 2008 (productivity data). Market figures marked [Source: verify] require confirmation with primary market research publications. Global prevalence estimates reflect self-reported or survey-based data and should be interpreted as approximations.

Frequently Asked Questions

How many people have seasonal allergies?
Approximately 26% of US adults (about 67 million) reported seasonal allergic rhinitis in the 2021 CDC National Health Interview Survey. An additional 5.2 million US children have been diagnosed with hay fever. Globally, allergic rhinitis (including seasonal and perennial) affects an estimated 400 million people according to the World Allergy Organization.
Is seasonal allergy season getting longer?
Yes. A landmark 2021 study in Proceedings of the National Academy of Sciences analyzing pollen monitoring data from across North America found that the pollen season had extended by approximately 20 days and pollen concentrations had increased by 21% between 1990 and 2018, with warming temperatures linked to earlier spring onset and delayed fall end of season.
What is the economic cost of seasonal allergies?
The direct and indirect economic burden of allergic rhinitis in the United States is estimated at over $11 billion annually by the American Academy of Allergy, Asthma and Immunology (AAAAI). When productivity losses from presenteeism (reduced productivity while at work or school) are included, the total burden is likely considerably higher. Seasonal allergies cause an estimated 3.5 million missed workdays per year.
Which US region has the worst seasonal allergies?
Seasonal allergy burden varies significantly by region. The Asthma and Allergy Foundation of America (AAFA) ranks cities by 'allergy capital' status based on pollen counts, allergy medication use, and allergy specialist access. Cities in the South-Central US (Texas, Oklahoma, Arkansas) and parts of the Southeast consistently rank among the highest-burden areas. The Pacific Northwest and Southern California have different but significant pollen profiles. See our seasonal allergy regions guide for regional detail.
What percentage of hay fever patients also have asthma?
Co-morbid asthma is extremely common in patients with allergic rhinitis. Approximately 20–50% of patients with allergic rhinitis have asthma, and over 80% of asthma patients have concomitant allergic rhinitis. This bidirectional relationship is captured in the 'united airway disease' concept, which recognizes rhinitis and asthma as manifestations of the same airway inflammatory process.

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Content is written by our editorial team following current clinical guidelines from ACAAI, AAAAI, and WAO. Educational only — always consult a qualified healthcare provider for medical advice. View editorial policy →

Medical References & Citations

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    Sampson HA, et al. "Second symposium on the definition and management of anaphylaxis: Summary report" — Journal of Allergy and Clinical Immunology.

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    American College of Allergy, Asthma & Immunology (ACAAI) "Allergy Facts and Figures" — ACAAI Clinical Resources.

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    World Allergy Organization (WAO) "White Book on Allergy — 2025 Update" — World Allergy Organization.

    View source
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    National Institute of Allergy and Infectious Diseases (NIAID) "Clinical Guidelines for the Diagnosis and Management of Food Allergy" — National Institutes of Health.

    View source
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    guideline2024

    Muraro A, et al. "EAACI food allergy and anaphylaxis guidelines: Diagnosis and management of food allergy" — Allergy — European Journal of Allergy and Clinical Immunology.

This content reflects clinical guidelines current as of the last review date shown above. Always consult a qualified healthcare provider for personalized medical advice.