Celery Allergy: The Complete EatSafe UK Guide
Celery has an image problem.
Not because people dislike it, but because it doesn't look particularly threatening.
A peanut comes with decades of public awareness attached to it. Most people understand that peanut allergy can be serious. Celery looks like the opposite: mostly water, rather virtuous, something you might dip into hummus when you're trying to be healthy.
Yet celery is one of the 14 allergens specifically regulated under UK food law, alongside peanuts, milk, eggs and mustard.
And celery allergy has another peculiarity.
For many people in Britain, the allergy may have begun not with celery at all — but with pollen blowing from a tree.
That connection takes us from a stick of celery to celeriac, birch trees, mugwort, molecular lookalikes, soups and stock cubes, and a newly recognised celery protein that may help explain why some people's reactions are much more serious than the familiar itchy mouth associated with pollen-food syndrome.
Celery turns out to be considerably more interesting than it looks.
Celery Allergy at a Glance
- Celery is one of the UK's 14 regulated allergens. When it is deliberately used as an ingredient in foods covered by UK allergen-labelling rules, its presence must be declared appropriately.
- Celeriac is celery. It is the swollen root form of celery and is covered by the same allergen requirement.
- Celery allergy can involve stalks, leaves, seeds, celery salt/spice and celeriac.
- In the UK, the most common form of celery allergy is thought to be associated with pollen-food syndrome, in which IgE originally directed against pollen cross-reacts with similar proteins in celery.
- Birch and mugwort pollen are particularly important in celery allergy.
- Pollen-food syndrome often produces itching or mild swelling of the lips, mouth and throat after raw celery, and some people tolerate cooked celery because certain cross-reactive proteins are heat-sensitive.
- That is not true for everybody with celery allergy. Some celery allergens are more resistant, and people can experience systemic reactions and anaphylaxis, including reactions to cooked celery.
- Celery can hide in soups, stocks, bouillons, sauces, stews, spice mixtures, salads, sandwiches, tomato juice, crisps and some meat products.
- Celery salt is not simply ordinary salt with a celery-like flavour. It can contain celery seed or celery-derived material and is relevant to celery allergy.
- A positive allergy test shows sensitisation, which needs interpreting alongside what actually happens when the person eats celery.
- Recent research has identified Api g 7, a celery allergen strongly associated with mugwort sensitisation and, in one study, a substantially greater likelihood of severe systemic reactions.
- If somebody has been prescribed emergency adrenaline, they should follow their individual emergency plan and current UK guidance. Anaphylaxis and adrenaline are covered separately in the EatSafe Knowledge Library.
Celery, celeriac and the vegetable that changes shape
Celery belongs to the species Apium graveolens.
But humans have cultivated different forms of the plant for different purposes.
The familiar celery stalk is grown for its crisp leaf stalks.
Celeriac, sometimes called celery root, is grown for the large swollen structure at its base.
Other varieties are cultivated for their leaves or seeds.
To a cook, celery and celeriac can look like completely different vegetables.
One is long, green and watery.
The other is round, knobbly, beige and looks rather like a turnip designed by someone having a bad day.
Biologically, however, they are forms of the same species.
And from the perspective of UK allergen information, celeriac comes under celery. The Food Standards Agency's celery definition includes the stalks, leaves, seeds and the root known as celeriac.
That is probably the first fact somebody with newly diagnosed celery allergy needs to learn:
"Celery-free" does not mean "I only need to avoid green celery sticks."
Why would somebody be allergic to celery?
As with other IgE-mediated food allergies, the immune system can produce IgE antibodies that recognise particular proteins in celery.
When those proteins are encountered, IgE bound to immune cells can help trigger the release of histamine and other chemical mediators, producing allergic symptoms.
EatSafe has a separate guide explaining how IgE-mediated food allergy works, so we don't need to rebuild the entire immune system here.
Celery becomes particularly interesting because in many patients the immune system may have learnt to recognise a similar protein somewhere else first.
That somewhere else can be a birch tree.
Where celery hides
The celery stick is the easy bit.
The difficult celery is the celery somebody used because it makes food taste better.
Celery contributes savoury flavour and is frequently used as a base ingredient rather than the star of a dish.
The Food Standards Agency specifically notes celery in forms including stalks, leaves, seeds and celeriac, and identifies foods such as celery salt, salads, some meat products, soups and stock cubes. Anaphylaxis UK adds examples including sauces, stocks, bouillons, seasonings, stews, tomato juice, sandwiches, crisps, spice mixes, batter for frozen foods and some cured bacon.
Rather than memorising a frightening list, it is better to understand why celery is there.
UK labels give celery an important advantage
Celery is one of the 14 allergens for which UK food law requires specific allergen information when it is used as an ingredient.
For prepacked food, allergenic ingredients must be emphasised in the ingredients list — commonly using bold type, although other methods of emphasis are possible.
The requirement also applies to relevant additives, processing aids and other substances present in the final product.
So an ingredients list might contain:
vegetable stock (water, onion, carrot, CELERY, herbs...)
The important habit is still to read the whole ingredients list, not simply scan familiar packaging.
Recipes change.
And online information can lag behind the physical product.
EatSafe's general Shopping and Checking Food Information guide covers that problem in more detail.
What does a celery reaction look like?
Celery can produce IgE-mediated allergic reactions ranging from relatively local symptoms to serious systemic reactions.
Possible symptoms can include:
itching or tingling in the mouth;
hives;
swelling;
gastrointestinal symptoms;
wheezing or breathing difficulty;
throat symptoms;
dizziness or collapse.
Some pollen-associated celery reactions may predominantly involve the mouth and throat, particularly with raw celery.
But celery is also capable of causing anaphylaxis.
The presence of pollen-food syndrome in some people should therefore not lead to the general conclusion that celery allergy is always mild.
Different molecular sensitisation patterns can produce different clinical pictures.
And previous reaction severity does not provide a perfect forecast of the next exposure.
EatSafe's separate guides to recognising anaphylaxis and adrenaline and food-allergy emergencies cover those subjects in detail rather than reproducing them here.
How is celery allergy diagnosed?
Diagnosis begins with the clinical history.
What was eaten?
Was celery definitely present?
Was it raw or cooked?
How quickly did symptoms begin?
What symptoms occurred?
Has celery been eaten safely at other times?
Does the person have birch or mugwort pollen allergy?
Do they react to carrot, spices or other related plant foods?
That pollen history can be particularly informative in celery allergy because of the cross-reactive syndromes described earlier.
Skin-prick testing and specific-IgE blood testing may support the diagnosis.
In some circumstances, component-level testing can provide additional information about the proteins being recognised.
Where uncertainty remains and it is clinically appropriate, a medically supervised oral food challenge may sometimes be used.
But the same important rule applies as for every food allergy:
A positive allergy test demonstrates sensitisation; it does not, by itself, prove that eating celery causes clinical allergy.
Our EatSafe Knowledge articles on food-allergy diagnosis, skin-prick and blood tests, and oral food challenges explain those distinctions in depth.
Celery Allergy at a Glance
For somebody who wants the practical version rather than the molecular tour:
- Celery is one of the UK's 14 regulated allergens.
- Celery allergy can range from pollen-associated mouth symptoms to serious systemic reactions, including anaphylaxis.
- Celeriac is celery and should be treated as such by somebody who needs to avoid celery.
- Celery seed, celery powder and celery salt can also matter.
- Celery commonly hides in stocks, soups, sauces, gravies, stews, seasonings and aromatic vegetable bases.
- Removing visible celery from a dish does not make celery-containing food celery-free.
- Some celery allergy is associated with birch and mugwort pollen cross-reactivity.
- Related foods such as carrot, parsley, fennel and spices should not automatically be removed merely because they are botanically or immunologically related.
- Cooking may reduce the allergenicity of some celery proteins for some pollen-related patients, but cooked celery cannot be assumed safe for everybody with celery allergy.
- A positive allergy test is not automatically proof of clinical allergy.
- When eating out, ask about stock, sauces, seasoning and the base of the dish, not just visible celery.
- UK/EU allergen labelling gives celery specific protection, but international rules differ.
- Anyone prescribed adrenaline auto-injectors should follow their individual emergency plan, keep their prescribed devices accessible and know how to use them.
Most importantly, celery allergy should be managed according to what the individual actually reacts to, rather than automatically avoiding an entire botanical family.
Things you may not have known about celery allergy
Celery turns out to contain several surprises.
Celeriac is celery. They look completely different in the supermarket, but both are forms of Apium graveolens.
A tree can be part of the reason somebody reacts to celery. Birch pollen's major allergen, Bet v 1, has a molecular relative in celery, Api g 1. The immune system can sometimes recognise both.
Mugwort pollen can be involved too. Celery forms part of recognised pollen-food cross-reactivity patterns involving mugwort and various spices.
The stalk isn't necessarily the most hidden form. Celery seed, celery powder, celery salt and celery-containing stock can disappear much more effectively into manufactured and restaurant food.
Celery can be in a dish before the dish really exists. In mirepoix and soffritto-style cooking, celery is used near the beginning to build flavour. Hours later, there may be no recognisable celery left in the finished sauce or stew.
Cooking isn't a universal solution. Some pollen-related celery proteins are relatively heat-sensitive, which helps explain why certain people tolerate cooked celery better than raw. Other celery allergens can be more resistant. "Cooked celery is safe" is therefore not a general rule.
A positive celery test isn't necessarily a celery allergy. Cross-reactive pollen antibodies can complicate testing, so results need to be interpreted alongside what actually happens when the person eats celery.
And perhaps most importantly:
Celery allergy is not simply an allergy to a vegetable.
For one person it may involve stable food proteins capable of producing systemic reactions.
For another, it may sit within a network connecting birch pollen, mugwort, celery and other plant foods.
The word celery on the medical record can therefore conceal rather different immunological stories.
Living safely with celery allergy
Once somebody understands where celery is actually used, it becomes much easier to ask useful questions.
At home, UK allergen labelling provides an important safety net.
In restaurants, think beyond the celery stick: stock, soup, gravy, sauce, seasoning and the base of slow-cooked dishes are often the more useful places to investigate.
Remember celeriac.
Remember celery seed and celery salt.
Don't assume cooking removes the problem.
But equally, don't turn every member of the carrot and parsley family into a forbidden food without evidence that it causes a problem for you.
That balance matters.
Food-allergy knowledge should identify the things somebody genuinely needs to avoid without unnecessarily taking safe foods away from them.
Celery may be capable of disappearing into a stockpot, crossing molecular paths with spring pollen and turning up in foods where nobody can see it.
But once you understand those patterns, it becomes considerably less mysterious.
And that is the purpose of good allergy information:
not to make food seem more dangerous, but to make the real risks easier to recognise.
EatSafe UK provides educational information and does not diagnose food allergy or replace individual medical advice. Anyone who suspects a food allergy should seek advice from an appropriately qualified healthcare professional. People prescribed emergency medication should follow their individual allergy action plan.
Sources and further reading
- Allergen guidance for food businesses — Food Standards Agency
- Celery allergen definition — Food Standards Agency
- Celery allergy factsheet — Anaphylaxis UK
- Role of Api g 7 in mugwort pollen-related celery allergy — Journal of Allergy and Clinical Immunology
- EAACI guideline on diagnosing IgE-mediated food allergy
- EAACI guideline on managing IgE-mediated food allergy
- Emergency treatment of anaphylaxis — Resuscitation Council UK