Celery allergy occurs when the immune system mistakenly identifies proteins in the celery plant as a threat. The severity of reactions ranges from relatively mild symptoms localized in the mouth to a potentially life-threatening systemic reaction called anaphylaxis. While the allergy is more commonly recognized in parts of Europe, it is a medical issue globally, requiring careful avoidance and preparedness.
The Specific Proteins Causing the Reaction
The primary allergen in celery is designated as Api g 1, which the immune system targets with immunoglobulin E (IgE) antibodies. This protein is a homologue of the major birch pollen allergen, Bet v 1, explaining a common overlap in sensitivities.
The celery plant, Apium graveolens, belongs to the Apiaceae family, which also includes many other common vegetables and spices. The structural similarity between Api g 1 and proteins in birch pollen is the basis for Pollen-Food Allergy Syndrome (PFAS), also known as Oral Allergy Syndrome (OAS). This reaction is typically milder, causing symptoms mainly in the mouth and throat after consuming raw celery.
A less common but more severe form is a primary celery allergy, which can be linked to other allergens in the plant, such as the lipid transfer protein Api g 2. Unlike the pollen-related variety, this primary allergy may cause systemic reactions and can be triggered by both raw and cooked celery. The mugwort pollen allergen Art v 1 is also strongly linked to severe celery allergy.
Recognizing the Signs of an Allergic Response
Symptoms of a celery allergy can manifest quickly, often within minutes of ingestion or contact. The most frequent initial symptoms are mild and localized to the mouth and throat, characteristic of Oral Allergy Syndrome. This includes itching, tingling, or slight swelling of the lips, tongue, or pharynx.
More severe, systemic reactions can affect multiple body systems. These include skin reactions like hives or generalized itching, as well as gastrointestinal distress. Symptoms such as abdominal pain, nausea, vomiting, or diarrhea signal a more widespread reaction.
The most serious presentation of celery allergy is anaphylaxis, a rapid, life-threatening reaction. Anaphylaxis can involve respiratory issues, such as wheezing, shortness of breath, throat tightness, or difficulty swallowing. Cardiovascular involvement may lead to a drop in blood pressure, causing dizziness, weakness, or collapse.
Cross-Reactivity and Hidden Sources
Celery’s inclusion in the Apiaceae family means that individuals with a celery allergy often experience cross-reactivity with other botanically related foods. Common cross-reactive items include:
- Spices such as anise, coriander, caraway, dill, and parsley.
- Vegetables like carrots, parsnips, and celeriac.
Celeriac, the root of a celery variety, is a potent allergen. Even cooking does not always fully eliminate the allergenicity, especially for celery spice.
Celery is a common hidden ingredient in many processed and prepared foods. It is frequently used as a flavor enhancer in stock cubes, bouillon, soups, and packaged sauces. Alternative names to look for on ingredient labels include celery seed, celery salt, and sometimes “natural flavorings,” which can mask the presence of celery.
Medical Confirmation and Emergency Care
Confirming a suspected celery allergy requires consultation with an allergist, who uses a combination of diagnostic methods. The standard procedure includes a review of the patient’s medical history alongside specific allergy tests. Skin prick tests are performed by introducing a small amount of celery extract into the skin to observe for a localized reaction, such as a raised welt.
Blood tests measure the level of IgE antibodies specific to celery proteins in the bloodstream. These tests help determine the immune system’s sensitization and can sometimes distinguish between the milder, pollen-related allergy and the more severe primary allergy. All allergy testing must be conducted under medical supervision.
For managing acute symptoms, mild reactions are often treated with antihistamines. However, for anyone diagnosed with a risk of systemic or severe reactions, emergency preparedness is necessary. This involves being prescribed and trained on the use of an epinephrine auto-injector, an emergency medication that rapidly reverses the symptoms of anaphylaxis. Developing a written Anaphylaxis Action Plan with an allergist provides clear instructions on when and how to use the auto-injector and what subsequent medical steps to take.