Over the past several decades, many clinicians, researchers, and parents have asked: Are allergies on the rise in children? While it can be tempting to attribute everything to “kids these days and their sensitivities,” the data suggest that, yes, many forms of childhood allergic disease appear to have increased in prevalence — though the picture is complex, with variations by type of allergy, region, diagnostic practices, and other factors. In this article, we’ll examine recent statistics, trends over time, possible explanations, and limitations to interpret the evidence accurately.
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What Do the Numbers Say? Key Statistics on Childhood Allergies
United States: Recent Data from the National Health Interview Survey (NHIS)
A recent CDC data brief (No. 459) based on the 2021 NHIS indicates that:
- 27.2% of U.S. children aged 0–17 years had at least one diagnosed allergic condition (seasonal allergies, eczema/atopic dermatitis, or food allergy) in 2021.
- The breakdown: 18.9% had seasonal (respiratory) allergies, 10.8% had eczema, and 5.8% had a food allergy.
- Among racial/ethnic groups, non-Hispanic Black children were more likely than non-Hispanic White or Hispanic children to have food allergies.
These figures reflect a snapshot in time, but trend data help us see how prevalence may have shifted.
Trend Comparisons: Then vs. Now
- In earlier NHIS cycles (2009–2011), about 17.0% of children had respiratory allergies, 12.5% had skin allergy (eczema), and 5.1% had food allergies.
- Comparing to 2021, respiratory/seasonal allergies have increased (from ~17.0% to ~18.9%), while eczema prevalence appears to have decreased (from ~12.5% to ~10.8%).
- A recent epidemiological study observing U.S. children during the COVID-19 period reported that respiratory allergies increased, while skin allergies and asthma decreased compared with pre-COVID years.
- Globally, data from multinational surveys (e.g. ISAAC) show upward trends over decades in rates of asthma, allergic rhinitis / rhinoconjunctivitis, and eczema across many countries, especially in more urbanized or Westernized settings.
- In food allergies specifically, a report by Food Allergy Research & Education (FARE) notes that food allergy prevalence in children has increased ~50% between 1997 and 2011, and again ~50% between 2007 and 2021.
Thus, the longer-term picture suggests that many allergic conditions in children have become more common over time — though the pattern is not uniform across types or locations.
Interpreting the Trends: What’s Driving the Increase?
While the raw numbers suggest rising allergy burdens in children, the “why” is more nuanced. Several hypotheses and contributing factors have been proposed:
- Hygiene / “Old Friends” / Microbial Hypothesis
One of the most-discussed theories is the “hygiene hypothesis” (or its more refined descendants like the “old friends” hypothesis). The idea is that reduced early-life exposures to microbes (due to cleaner water, smaller family sizes, less time outdoors, more antibiotics, etc.) may limit proper immune system training, making allergic responses more likely. Over-sterilization of environments may inadvertently push immune responses toward overreacting to harmless substances (allergens).
- Westernization, Urbanization & Environmental Change
- Pollution, air quality, and indoor allergens (e.g. dust mites, mold, cockroach) may exacerbate the development or severity of allergies.
- Diet and lifestyle shifts toward more processed foods, lower fiber, and altered gut microbiomes may play a role.
- Changes in infant feeding practices: delayed introduction of allergenic foods, increased use of formula, and lower microbial diversity in the gut early on are being studied as contributors to allergy risk.
- Increased Awareness, Diagnostic Change & Reporting
Some of the rise may be “artifactual” — that is, due to:
- Better diagnostic tools, more screening, and greater parental awareness.
- Changes in survey design, questionnaire wording, or definitions of “diagnosed allergy” (notably, the NHIS questionnaire changed wording in 2019, affecting comparability)
- Greater medical access and health-seeking behavior, leading to more children being evaluated and labeled with allergic conditions.
- Genetic Predisposition Interacting with Environment
While genetics don’t change quickly over decades, genetic predisposition (having parents with allergies or asthma) is a known risk factor. The rising incidence may reflect gene-environment interactions: children with allergy-susceptible genetic backgrounds encounter more modern environmental triggers than past generations did.
- COVID-19 Pandemic Effects
The pandemic created unusual conditions: lockdowns, mask-wearing, less outdoor exposure, changes in social mixing, and altered exposures to allergens. Some data suggest that respiratory allergies increased while skin allergies and asthma decreased during the COVID era. The longer-term impacts of these shifts remain under investigation.
Do All Allergies Follow the Same Pattern?
No — trends differ by type of allergy and age group:
- Respiratory / Seasonal Allergies: These appear to have increased modestly in recent years in U.S. children.
- Eczema / Atopic Dermatitis: Surprisingly, some data indicate a decrease in recent years in U.S. children, though globally, eczema has shown long-term increases.
- Food Allergies: This is one of the most consistently rising allergy types across multiple studies. The FARE data and other sources suggest a doubling or more over decades.
- Asthma / Allergic Comorbidities: Asthma trends are mixed; some studies show plateauing or modest decreases in certain ages, possibly influenced by improved asthma care, prevention, or environmental regulations.
Thus, “allergies in children” is an umbrella category; each subtype must be considered individually.
Limitations & Caution in Interpretation
When assessing whether allergies are truly increasing, here are some caveats:
- Change in Definitions & Survey Methods
Because survey questions and diagnostic criteria evolve, direct comparisons across decades may be imperfect. For example, the NHIS questionnaire wording changed in 2019, affecting prevalence estimates. - Self-reported vs. Confirmed Diagnoses
Many prevalence statistics rely on parent-reported diagnoses, which may overestimate true allergies (versus clinical, challenge-confirmed diagnoses). - Access and Reporting Bias
Increased medical access, insurance coverage, and public awareness may inflate diagnostic rates (i.e., more children are tested and diagnosed now than in prior eras). - Regional / Socioeconomic Variation
Allergy trends vary by region, climate, socioeconomic status, race/ethnicity, and urban vs. rural living. National averages may hide disparities. - Lag Time and Generational Effects
Environmental and lifestyle changes may take years to manifest fully in health outcomes; what we observe now may reflect exposures from decades earlier.
Bottom Line: Are Childhood Allergies Increasing?
Based on the balance of evidence:
- Yes — many types of allergy, especially food allergies and respiratory (seasonal) allergies, show a credible upward trend over past decades in children.
- However, the rate and timing of increase are not uniform, and some allergic conditions (such as eczema or asthma) show more complex or even declining trends in certain populations.
- Part of the increase likely reflects greater awareness, more diagnoses, and changing survey methods, but that does not fully account for the magnitude of rises seen in many studies.
In short: the rise in childhood allergies appears to be a real phenomenon, not merely a diagnostic artifact — but interpreting that rise requires nuance and an understanding of underlying drivers.
Implications & What to Watch Next
- Preventive Strategies: Research into early-life exposures, microbiome development, dietary diversity, and environmental controls offers hope for modulating allergy risk.
- Health Equity: Address disparities in diagnosis and care across racial and socioeconomic groups, since some children may be underdiagnosed or undertreated.
- Longitudinal Research: Continuously track cohorts over time, with consistent definitions and objective testing, to clarify the true trends.
- Public Health Planning: Rising allergy burdens increase healthcare use, emergency visits, medication needs, and educational accommodations — policies and infrastructure must adapt.
READ MORE: Eating Well with Food Allergies: Tailoring Your Diet for Health and Comfort
Sources:
https://www.cdc.gov/nchs/data/databriefs/db459.pdf
https://www.uspharmacist.com/article/trends-in-allergic-conditions-among-us-children
https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-024-19639-8
https://bmjopen.bmj.com/content/14/4/e080612
https://www.foodallergy.org/sites/default/files/2024-07/FARE%20Food%20Allergy%20Facts%20and%20Statistics_April2024.pdf