Allergy risk

What's their risk of allergies?

Atopy — eczema, food allergy, asthma, hay fever — runs strongly in families. Knowing the risk early lets you make better calls on early food introduction, eczema care, and pet ownership.

Mom's atopic conditions
Select all that apply, or none
Dad's atopic conditions
Select all that apply, or none
Older sibling already?
Chance of developing some allergic condition
15%vs. 25% baseline
In or near the typical range.
Compared to baseline
For your baby15.0%
Average baby25.0%
Risk by specific condition
Eczema12% · baseline 12%
Asthma8% · baseline 8%
Hay fever15% · baseline 15%
Food allergy8% · baseline 8%
Conditions you both share carry the highest risk for that specific condition — that's the strongest signal in the literature.
What actually moves the needle
  • Early peanut introduction (4-6 months)
    Reduces peanut allergy risk by ~80% in high-risk infants. The LEAP trial changed pediatric guidance worldwide.
  • Aggressive eczema treatment
    Healthy skin is a huge protective factor. Don’t under-treat — talk to a derm if OTC isn’t cutting it.
  • Diverse early diet
    Introducing varied foods between 4-12 months is associated with lower allergy rates.
  • Pets in the first year
    Counterintuitively, exposure to cats and dogs early is associated with fewer allergies.
How accurate is this, honestly?
AccuracyFamily-history-based

Family history is the strongest single predictor of atopic disease (the umbrella term for eczema, food allergy, asthma, and allergic rhinitis). With no atopic parent, ~10–15% of children develop some atopic condition. With one atopic parent, that rises to roughly 25–30%; with two, ~40–60% depending on which conditions the parents have. The pediatric literature calls the typical progression — eczema in infancy, food allergy in toddlerhood, asthma in childhood, allergic rhinitis by adolescence — the atopic march.

What changes outcomes within that genetic backdrop is largely first-year-of-life: early peanut introduction (Du Toit et al. 2015, NEJM LEAP trial) cut peanut allergy by ~80% in high-risk infants vs. delayed introduction. AAP now recommends introducing peanut-containing foods around 4–6 months for high-risk infants, with allergist input where appropriate. Aggressive eczema treatment (skin barrier preservation) is also protective.

Even at 70%+ predicted risk, plenty of those kids never develop a single allergy. Risk isn't destiny — and the choices in the first year matter. This is the calculator most worth taking to your pediatrician.

Sources: Du Toit G et al. N Engl J Med 372:803–13 (2015), "Randomized trial of peanut consumption in infants at risk for peanut allergy" (LEAP); Togias A et al., Addendum guidelines for the prevention of peanut allergy in the United States (NIAID-sponsored expert panel, 2017); AAP Section on Allergy & Immunology guidance.

Read the full methodology →
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