Tree nut allergies: what counts as a tree nut?

“Tree nut allergy” is one of those phrases that sounds simple until you start asking questions. Which nuts actually count? Does a peanut count? What about coconut, water chestnut, nutmeg?

This is the practical answer: which nuts are real tree nuts, which sound like tree nuts but aren’t, what hidden sources to watch for, and what should go on a tree nut allergy card.

What is a tree nut?

A tree nut is a hard-shelled, dry fruit that grows on a tree. Botanically the definition is fussier than that, but for allergy purposes the working list of common tree nuts is:

• Almonds
• Brazil nuts
• Cashews
• Chestnuts (sweet chestnut, not water chestnut — see below)
• Hazelnuts (also called filberts)
• Macadamia nuts
• Pecans
• Pine nuts (technically seeds, but treated as tree nuts in allergy labelling)
• Pistachios
• Walnuts

In the UK and EU, all of these are part of the 14 major allergens that must be emphasised on food labels under the Food Information Regulations.

Common tree-nut confusion

Peanuts are NOT tree nuts

Peanuts are legumes — they grow in pods underground, not on trees. They’re related to peas, beans, and lentils.

Why does this matter? Two reasons:

1. You can be allergic to peanuts and not tree nuts (or vice versa) — the two are biologically different.
2. About a third of people with a peanut allergy also have a tree nut allergy, but it’s not automatic.

If you’re allergic to one, get tested for the other. Don’t assume avoidance overlaps neatly.

Coconut is technically a tree fruit, not a tree nut

Despite the name, coconut is a drupe (a stone fruit, like a peach). Most people with tree nut allergies tolerate coconut fine. The FDA lists coconut as a tree nut for labelling purposes; the UK and EU don’t. If you have a tree nut allergy and want to eat coconut, talk to your allergist first — but don’t assume coconut is automatically off-limits.

Nutmeg is a seed, not a tree nut

Nutmeg comes from a seed of the Myristica fragrans tree. It’s not allergenically related to tree nuts and is usually safe for tree-nut allergy sufferers.

Water chestnut is not a nut at all

Water chestnut is an aquatic vegetable. Safe for tree nut allergies.

What about “nut-free chocolate” that may contain nuts?

Welcome to the world of may-contain labels. Even chocolate marketed as nut-free is often made in a factory that handles tree nuts, and that’s enough to make it unsafe for a severe allergy. Always check for cross-contamination notices.

Hidden sources of tree nuts

Tree nuts show up in places you might not expect:

• Pesto — pine nuts (sometimes walnuts or cashews)
• Marzipan and almond paste — almonds
• Praline and gianduja — hazelnuts
• Some breads — walnuts, pecans, or sometimes seeds processed alongside nuts
• Asian dishes — cashews are common in Indian and Chinese cooking; pad thai often uses peanuts but sometimes cashews
• Pesto-style sauces and dips — hazelnut, almond, or walnut bases
• Salads with “candied nuts” — usually pecans or walnuts
• Ice cream and gelato — pistachio, hazelnut, walnut, almond
• Worcestershire sauce — some brands include walnut
• Baklava, biscotti, nougat — almonds, pistachios, walnuts
• Some vegan cheeses — cashews are the most common base
• “Natural flavourings” — can include nut derivatives

For a more general overview of hiding ingredient names, see our post on hidden allergens in food labels.

What goes on a tree nut allergy card

A useful tree nut allergy card lists:

• The specific nuts to avoid — “all tree nuts including almond, cashew, walnut, pecan, hazelnut, macadamia, pistachio, brazil, pine nut, chestnut”
• Severity — particularly if anaphylactic
• Cross-contamination warning — “Please prepare on a clean surface with clean utensils. Avoid shared fryers and shared chopping boards.”
• Whether an EpiPen is carried
• Emergency contact

For a child with a tree nut allergy, also add their school or activity contact and any specific reaction notes.

Travel and tree nuts

Pesto in Italy. Pad thai in Thailand. Cashew curries in India. Marzipan in Germany. Pistachio gelato everywhere.

Tree nuts are deeply embedded in cuisines you’ll want to eat when travelling, which makes a translated chef card essential. AllergIQ translates allergy cards into dozens of languages, so you can hand kitchen staff a clear list of which nuts to avoid in a script they can read.

For severe allergies, also carry your EpiPen at all times — air travel, restaurants, and unfamiliar food environments are the highest-risk scenarios.

When to get tested

If you suspect a tree nut allergy:

• Don’t try to self-diagnose with an avoidance trial. Get a referral to an allergist.
• Skin prick tests and specific IgE blood tests are the standard diagnostics.
• A specific IgE test can tell you which nuts you react to — useful, because you may be allergic to some tree nuts and tolerate others.

The NHS provides referrals through your GP; private clinics offer faster access. Allergy UK maintains a list of accredited allergy clinics.

Living with a tree nut allergy

A few practical habits make a big difference:

• Carry your EpiPen everywhere — even if you’ve had mild reactions before, the next one can be severe.
• Tell people early — friends, restaurants, hosts at events. Embarrassment kills more reactions than convenience.
• Use a printed allergy card for restaurants, especially abroad.
• Use an AI ingredient scanner for packaged foods — particularly useful for hidden tree-nut derivatives like marzipan-based fillings or nut oils.
• Keep a list of safe brands — the products you’ve already checked and trust.

Tree nut allergies aren’t usually outgrown the way milk or egg allergies often are. But with the right tools and habits, they’re entirely manageable — at home, while travelling, and eating out.