A hazelnut allergy occurs when the immune system overreacts to specific proteins in hazelnuts, a common tree nut allergy. The body mistakenly identifies these proteins as harmful, triggering an allergic response. Reactions vary from mild discomfort to severe, potentially life-threatening symptoms.
Recognizing Allergy Symptoms
Symptoms of a hazelnut allergy can manifest rapidly, often within minutes of exposure. Mild reactions include skin itching, hives, an itchy mouth or ears, a scratchy throat, or swelling of the lips, face, or tongue. Digestive issues like nausea, abdominal pain, vomiting, or diarrhea may also occur.
Anaphylaxis, a more severe reaction, affects multiple body systems. Symptoms include difficulty breathing, wheezing, swelling of the throat or airways, dizziness, fainting, a rapid pulse, or a sudden drop in blood pressure.
Getting a Diagnosis
Confirming a hazelnut allergy typically involves consultation with an allergist. They will take a detailed medical history, including symptoms after consuming hazelnuts and family allergy history.
A skin prick test is a common diagnostic method where a small amount of hazelnut extract is applied to the skin. A positive reaction, indicated by a raised bump, suggests sensitization to hazelnuts. Blood tests, which measure specific IgE antibodies to hazelnut proteins, also confirm an allergy.
The oral food challenge is considered the most definitive diagnostic test, often performed when other tests are inconclusive or to determine if an allergy has been outgrown. It involves consuming increasing amounts of hazelnuts under strict medical supervision. Medical professionals must confirm any suspected allergy; self-diagnosis should be avoided.
Living with a Hazelnut Allergy
Managing a diagnosed hazelnut allergy primarily involves strict avoidance of hazelnuts and products containing them. Carefully read food labels for “Contains: Tree Nuts” warnings. Hazelnuts can be present in various unexpected foods, including baked goods, chocolates, spreads, and some oils. Cross-contamination can also occur during food processing, so checking for “may contain” advisory panels is advisable.
Dining out or attending social gatherings requires proactive communication about the allergy to restaurant staff or hosts. Informing others helps prevent accidental exposure and cross-contact. Designating separate cooking utensils and thoroughly cleaning surfaces at home also helps prevent cross-contact.
Preparation for potential accidental exposure is important. Individuals at risk for severe reactions should have an emergency action plan and carry an epinephrine auto-injector at all times. Epinephrine is the primary treatment for anaphylaxis and should be administered immediately at the first sign of severe reaction. After administering epinephrine, seeking emergency medical attention is necessary, even if symptoms subside, due to the possibility of a second reaction hours later.
Understanding Cross-Reactivity
Some individuals with a hazelnut allergy may experience reactions due to cross-reactivity, where hazelnut proteins are similar to other substances. Oral Allergy Syndrome (OAS) is a common example, particularly among those with birch pollen allergies. In OAS, the immune system recognizes similar proteins in birch pollen and hazelnuts, leading to allergic symptoms.
The symptoms of OAS are typically mild and localized to the mouth and throat. Symptoms include itching or tingling in the mouth, lips, tongue, or throat. Itchy ears and hives around the mouth may also occur. These reactions usually subside quickly once the food is swallowed or removed.
Other foods can also cause OAS in individuals allergic to birch pollen, such as apples, carrots, and celery. Managing OAS often involves avoiding the raw form of the food, as cooking can break down the proteins responsible for the reaction. This heat sensitivity often allows individuals with OAS to tolerate cooked hazelnuts.