Eating in Vietnam with an allergy, and the two ingredients that hide

Vietnamese food is fresh, largely unprocessed and cooked in front of you, which makes it sound like an easy cuisine to navigate with an allergy. Two things complicate that badly: fish sauce is in nearly everything savoury, and peanuts are on top of nearly everything else.

Which food allergies in Vietnam are the hard ones?

Four: fish sauce, peanuts, shellfish and egg. Each of them hides in dishes that look free of it, and the last two arrive after the cooking is done, which is what makes a kitchen's honest answer unreliable.

Fish sauce is the base seasoning of the country. It is in marinades, in broths, and in the dipping sauces that look like nothing but chilli, lime and water. A dish with no visible fish is not a dish with no fish.

Peanuts are a finish rather than an ingredient, which is worse. They go on at the last moment, after the dish is made: noodle salads, grilled scallops, banh cuon, che desserts. A kitchen can honestly say a dish contains no peanuts and then garnish it.

Shellfish appears as dried shrimp and shrimp paste in seasoning as well as as visible shellfish, particularly in bun bo Hue and in many dipping sauces.

Egg turns up in banh mi spreads, in some noodles and in the coffee, where egg coffee is a Hanoi speciality.

Are food allergies in Vietnam harder if you avoid gluten?

Less than its reputation. Yes, the staple noodles are rice and the country runs on rice, and that is a real advantage over most of Europe.

But soy sauce is brewed with wheat, and so is hoisin. Several thickened sauces use wheat starch. A fryer that cooks battered items also cooks everything else. Seitan is common in Buddhist vegetarian cooking, which is exactly the cuisine a gluten-avoiding vegetarian would otherwise reach for.

Coeliac disease needs the same care here as anywhere. Wheat avoidance by preference is straightforward, and rice noodles cover perhaps 80 percent of what you would want to order anyway.

What actually works?

A written card, in Vietnamese, naming the ingredient and stating plainly that it makes you seriously ill. Have it on your phone and on paper.

A written card works far better than speaking, for a reason the language guide explains: Vietnamese is tonal, a mispronounced word is a different word, and a noisy street stall is the worst possible place to test your accent. Stallholders read a card willingly and take it seriously.

Two spoken phrases are still worth having. Khong cay — not spicy. An chay — I eat vegetarian, which is the single most useful thing to say if fish sauce is the problem.

Why does the vegetarian route help?

Because Buddhist vegetarian cooking excludes fish sauce as a matter of religious practice rather than as a preference. A com chay kitchen is not making an exception for you; it never had the ingredient.

A kitchen that never stocked fish sauce is the most reliable place to eat with a fish or shellfish allergy, which is a slightly counterintuitive route to the answer. The vegetarian guide has the words and the caveats.

How do you handle a street stall?

Prefer stalls that sell one dish. A place that makes only 1 thing knows every ingredient in it, and the answer to your card is yes or no rather than a guess across a menu of 40.

Watch the finish. If peanuts are the problem, the moment to intervene is before the garnish goes on, not after, and pointing at the bowl of crushed peanuts while shaking your head is understood everywhere.

And accept that some things are not worth the risk. The street food safety guide makes the same point for different reasons: the cooked part is rarely the problem, and the parts added at the end are where the uncertainty lives.

What does a card actually need to say?

Four things, in Vietnamese: the ingredient, that you cannot eat it, that it makes you seriously ill, and thank you. Anything longer gets skimmed.

Name the ingredient in its everyday form rather than its category. Nuoc mam is fish sauce; mam tom is shrimp paste; dau phong is peanut. A card saying "no seafood products" is a category a stallholder has to interpret, and interpretation is exactly what you are trying to remove.

Carry 2 copies. One on the phone, which fails when the battery does, and one on paper, which does not. Restaurants in the main tourist towns increasingly keep allergen notes, but a stall serving 200 bowls a morning does not.

What about medical help?

Know where you would go. Vietnamese pharmacies are everywhere, and antihistamines cost a few tens of thousands of dong without a prescription — under 2 US dollars at mid-2026 rates of about 26,000 dong to the dollar. A serious reaction needs a hospital, and the good ones are in the 2 big cities.

If you carry an adrenaline auto-injector, carry two and keep them with you rather than in a hotel room — the health guide covers the insurance side, including why islands are further from a major hospital than they feel.