What is a food allergy?
If you or your child suffer from a food allergy, it means that your immune system overreacts to certain foods. This reaction is caused by a specific antibody called Immunoglobulin E (IgE), which targets a particular component in the food. Allergic symptoms can occur even with minimal exposure to the food, and sometimes mere contact with the lips can trigger a life-threatening reaction.
Which foods can cause sensitivity?
The most common food allergens are proteins found in cow's milk, eggs, sesame, peanuts, fish, shellfish, and nuts. There are also isolated cases of allergies to soy, wheat, and other foods like quinoa or tropical fruits. In some groups of foods, especially nuts and shellfish, an allergy to one item can cross-react with the entire group. Cross-reactivity is less common in animal food allergies. For example, people with a cow's milk allergy can usually tolerate beef, and those with egg allergies can often consume chicken.
Most food allergens can cause a reaction even after they are cooked or processed, although there are a few exceptions. Some allergens, usually fruits and vegetables, may only trigger a reaction when eaten fresh, and the symptoms are usually limited to the mouth and throat.
What are the symptoms?
Food allergy symptoms are typically visible on the skin (red patches, irritation, and swelling). There can also be gastrointestinal symptoms, including vomiting and diarrhea. In some cases, respiratory symptoms can occur, primarily shortness of breath, although these symptoms are usually not isolated and are accompanied by other reactions.
Severe allergic reactions:
Anaphylaxis is a severe allergic reaction that occurs rapidly and can be life-threatening. Anaphylactic symptoms include, among others, hives or swollen hives, difficulty breathing, wheezing, a feeling of suffocation, dizziness, and in extreme cases, loss of consciousness and even death.
If there is a suspicion of an anaphylactic reaction, you should immediately administer adrenaline (epinephrine) using an auto-injector (EpiPen), call emergency services, and seek immediate medical attention. Do not wait to see if the symptoms resolve on their own. Without prompt treatment, an anaphylactic reaction can be fatal.
After the treatment of an allergic reaction, it is essential to continue with medical evaluation and follow-up at an allergy clinic.
How is food allergy diagnosed?
Your medical history contains crucial information. Try to describe the relationship between the foods you eat, the frequency and severity of the allergic reaction, the nature of the symptoms you experience, and the time that elapses from consuming the food until the reaction occurs.
Skin tests can help determine if you or your child are sensitive to certain types of food, although not all food allergies can be diagnosed using this method. In cases where skin tests cannot be performed, such as patients suffering from acute eczema, a blood test may be conducted.
It's important to note that both skin tests and blood tests can yield false positive results (indicating an allergy when there isn't one) or false negative results (failing to detect an allergy that exists). Therefore, the choice of tests and their interpretation must be individualized for each patient.
An additional test is the oral food challenge, where the suspected food is ingested under medical supervision. This test is only performed in an allergy clinic under the appropriate emergency treatment facilities in case of a severe allergic reaction.
Only after an oral food challenge shows no allergic reaction can it be declared that there is no allergy to the tested food.
How to manage food allergy?
The best approach to managing a food allergy is to avoid the foods that trigger the allergic reaction. It's essential to be aware that sometimes allergens can also cause reactions through airborne exposure, mainly in the form of particles or vapors. And as mentioned before, avoid consuming the food even if it's cooked.
Therefore:
- Always inquire about the ingredients of a dish when eating outside your home.
- Thoroughly read food labels. Many countries, including the United States, require food manufacturers to clearly label if a product contains allergens in simple and clear language.
- Always carry epinephrine auto-injectors and antihistamines and know how to use them in case of an emergency.
- Educate family members and close contacts on how to use auto-injectors.
- Wear an identification bracelet that describes your food allergy.
- If you experience an allergic reaction, make sure someone takes you to the emergency room, even if the symptoms subside, and contact the allergy clinic for further evaluation and treatment.
When can you eat the food you are allergic to?
A condition in which the "allergy passes" is called desensitization or outgrowing the allergy, and it naturally occurs in some children who suffer from food sensitivities.
Many children develop desensitization to the food they were allergic to, such as cow's milk, eggs, soy, and wheat, even if they had a severe reaction in the past. About 20% of children with allergies to nuts and sesame seeds, and about 9% of children with allergies to peanuts, outgrow the allergy. It is crucial to avoid attempting to test if the allergy has passed without following the advice of the allergy specialist, as such attempts can be dangerous.