A food allergy occurs when the body’s immune system mistakenly identifies a protein in a particular food as a threat, triggering a defensive reaction. Celery contains several proteins capable of provoking such a response, making celery allergy a recognized and sometimes severe condition. While often overlooked compared to more common allergens like peanuts or milk, celery is considered one of the more frequent causes of food allergy in adults, particularly in central Europe.
Confirming Celery Allergy and Reaction Types
Reactions to celery can vary widely in intensity, ranging from localized discomfort to a life-threatening systemic event. The mildest form often presents as Oral Allergy Syndrome (OAS), where symptoms are confined to the mouth and throat area, developing immediately after contact. This localized reaction typically involves an itchy or tingling sensation in the lips, mouth, or throat, sometimes accompanied by slight swelling.
Systemic reactions may affect multiple organ systems. These signs can include hives or a rash on the skin, flushing, and gastrointestinal distress such as abdominal pain, nausea, or vomiting. The most severe reaction is anaphylaxis, which can rapidly progress to difficulty breathing, a sudden drop in blood pressure, a rapid pulse, or loss of consciousness. Allergic reactions can be triggered by raw celery stalk, cooked celery root (celeriac), or concentrated forms like celery seed.
The Link to Pollen Cross-Reactivity
The immune response to celery is frequently connected to existing seasonal allergies through a mechanism called cross-reactivity. This phenomenon occurs because certain proteins in celery structurally resemble proteins found in common airborne pollens. For many individuals, this is a link between celery and birch or mugwort pollen, often described as the “birch-mugwort-celery syndrome.”
The primary allergen responsible for this cross-reactivity is Api g 1, which shares structural similarities with the major birch pollen allergen, Bet v 1. Since Api g 1 is heat-labile (it breaks down at high temperatures), reactions linked to this protein typically occur only after eating raw celery and are usually limited to mild OAS symptoms. Other celery proteins, such as Api g 7, are more stable and can withstand cooking or processing. These stable proteins are capable of triggering more severe, systemic reactions. Sensitization to the mugwort pollen allergen Art v 1 is associated with an increased risk for these severe reactions involving the stable celery protein Api g 7.
Clinical Diagnosis and Testing
Diagnosing a celery allergy involves clinical history and specific diagnostic tests conducted by a healthcare professional. The initial assessment typically begins with a detailed review of the patient’s symptoms, the timing of the reaction, and the form of celery consumed. Allergy specialists often use a Skin Prick Test (SPT), where a small amount of celery extract is applied to the skin to check for an immediate localized reaction.
A specific IgE blood test is another common tool, measuring the level of immunoglobulin E antibodies in the bloodstream that are directed against celery proteins. Advanced testing may look for sensitization to specific allergenic components, such as Api g 1 or Api g 7, which can help predict the likelihood of a severe reaction. The most definitive method to confirm a true food allergy is the Oral Food Challenge, which involves consuming gradually increasing amounts of the suspected food under strict medical supervision.
Essential Avoidance and Management Strategies
The most effective strategy for managing a celery allergy is the complete avoidance of celery and all products containing it. This requires careful label reading, as celery is frequently used as a seasoning in processed foods, including stocks, bouillon cubes, spice mixes, and pre-made soups. Celery is also sometimes found in processed meats, where celery powder is used as a natural source of nitrates for curing.
In regions like the European Union, celery is listed as a major allergen and must be clearly highlighted on ingredient labels. For mild symptoms such as oral itching, an over-the-counter antihistamine may provide relief. For any sign of a severe, systemic reaction, the primary treatment is the prompt use of an epinephrine auto-injector. Individuals who have experienced systemic reactions should carry two epinephrine auto-injectors at all times and seek emergency medical attention immediately after administration, even if symptoms appear to improve.