a food allergy is an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food.
The disorder may be acute or chronic, immediate or delayed. Food allergies are classified as being “immediate” IgE-mediated, non-immunoglobulin E–mediated (NICE), and mixed IgE- and NICE-mediated based on the nature of the allergic reaction observed in susceptible individuals upon ingestion of certain foods.
Nine significant allergens have been identified as being responsible for 90% of allergic reactions to foods: cow’s milk protein, egg white, peanut, soybean, wheat, fish, shellfish (e.g., shrimp), sesame seed, and tree nuts (e.g., almonds, cashews, walnuts).
A food allergy is an abnormal immune-system response to a food. The body’s immune system produces Immunoglobulin E antibodies (IgE) in response to contact with the offending food. IgE antibodies attach to special cells called mast cells, present in significant numbers in specific tissues, such as the nose, mouth, throat, and gut lining.
When IgE antibodies bind to mast cells, they activate the cells and cause them to release histamine and other chemicals. These chemicals can cause a range of symptoms, from mild irritation to a potentially life-threatening reaction known as anaphylaxis.
Food allergies can be either immediate or delayed. Immediate food allergies are caused by the body’s immediate reaction to the food, usually within minutes of exposure. Primary food allergy symptoms can include hives, itching, swollen lips, tongue, or throat, wheezing, difficulty breathing, nausea, and vomiting.
Delayed food allergies develop hours to days after exposure to the food and cause various symptoms, including skin rashes, gastrointestinal problems, and respiratory problems.
The most common food allergens are cow’s milk protein, egg white, peanut, soybean, wheat, fish, shellfish (e.g., shrimp), sesame seed, and tree nuts (e.g., almonds, cashews, walnuts). Nine foods account for 90% of all food-allergic reactions.
A food allergy is diagnosed based on a patient’s medical history and a physical examination. There is no definitive test for food allergies. However, several tests may be used to help support a diagnosis, including skin prick tests, blood tests, and food elimination diets.
Treatment for food allergies depends on the severity of the reaction. For mild reactions, over-the-counter medications such as antihistamines may be helpful. Emergency treatment, including epinephrine (adrenaline) injections, may be necessary for more severe reactions. Long-term treatment with steroids or other medications may be required in some cases.
There is currently no cure for food allergies. The best way to avoid a reaction is to avoid the food that causes the allergy altogether. An allergist can assist patients in developing an effective management plan which includes educating family members and others close to the patient about the allergy, identifying high-risk situations, carrying emergency medications such as epinephrine pens, and making a plan for what steps should be taken if a severe reaction occurs.
common food allergies:
Some people are also allergic to soy, corn, and other foods. If you think you might be allergic to a food, see your doctor. They can help you figure out if you have an allergy and what to do about it.
Some rare kinds of food allergies can be dangerous. A person with one of these problems needs to see an allergist (say: all-uh-jist). An allergist is a doctor who treats people who have allergies.
A doctor might order skin tests, in which case they would scratch on your back or arm with tiny amounts of foods that most often cause allergic reactions. Sometimes the doctor uses blood tests instead or does both tests simultaneously.
First, the doctor checks how your body reacts to each substance by drawing blood from your arm. This test measures how many cells in your body “fight” against the substances tested, called antibodies. If you’re allergic to certain foods, you will have more antibody cells.
There is no cure for food allergies, but doctors can help you manage them. For example, you might need to avoid the food that causes your problems or take medicine if you eat it. In addition, some people with severe food allergies carry an EpiPen (say: ee-PEP) with them at all times in case they have an extreme reaction. An EpiPen is a device that gives you a shot of medicine to stop an allergic reaction from getting worse.
Food allergy treatment:
avoiding or limiting certain foods
using medicine to treat a reaction when it happens.
Everyone should know the major food allergies:
People with a peanut allergy might have a severe reaction called anaphylaxis if they eat them because peanuts contain proteins that the body sees as dangerous, even though they’re harmless to most people. Peanuts are one of the leading causes of anaphylaxis outside the hospital setting.
If you’re allergic to peanuts, you’re at high risk for any emergency involving food, such as choking on something else while eating because your throat is swollen from an allergic reaction. Some parents may think their child doesn’t have a peanut allergy if they haven’t reacted to peanuts. But replies can be delayed, so it’s essential to assume your child is at risk for this allergy.
2- tree nuts:
Tree nuts are the most common cause of severe allergic reactions in kids and adults who have allergies. These include peanuts, which botanically aren’t a nut but are treated as one because they’re nutritionally similar. Another nut that can cause problems is the Brazil nut, found chiefly in tropical regions around the globe.
Other examples of tree nuts include cashews, walnuts, almonds, pecans, pistachios, macadamia nuts, pine nuts, and hickory nuts. Tree nut allergies tend to last longer than peanut allergies, too – nearly 30% of people with tree nut allergies are still reacting to them at age 5, and 16% continue to have reactions even by age 10.
Seafood is the most common cause of severe allergic reactions in adults. Allergies to crustacean shellfish – including shrimp, crab, crayfish, lobster, and others – are often lifelong. Responses tend to be more severe than those caused by other foods. And they can happen quickly.
One minute you’re fine; five minutes later, you’re having trouble breathing. The good news is that many people who are allergic to one type of seafood are also allergic to another, so if you need to avoid one, you may be able to all of them. Fish allergies are less common in kids, but they can be severe.
Egg allergies are also common in kids. However, unlike some other food allergies, most kids outgrow egg allergies by reaching school age. But even if you’ve outgrown your allergy, you should still avoid eating eggs. That’s because there’s a slight chance you could react to eggs even if you haven’t had one before.
Soy is a legume, not a nut, commonly found in many different foods. Even a tiny amount of soy can cause problems for people with soy allergies. Soy is often hidden in foods as an additive or flavoring. It’s also used in some medications, so reading the label is essential before taking anything.
Milk is a common food allergen. It’s found in many different foods, from ice cream to cheese to pizza. And while most kids who are allergic to milk can drink soy milk without any problems, they can’t always eat other dairy products.
That’s because the proteins in milk are different than those in soy. If you’re allergic to milk, you need to be careful about what you eat. Fortunately, there are many non-dairy products available that you can enjoy.
Wheat is a grain and one of the most common food allergens. It’s found in many kinds of bread and pasta, as well as in many processed foods. Wheat is also one of the eight most common allergens in children with food allergies.
People with wheat allergies can usually eat other whole grains, such as rice, quinoa, amaranth, millet, and buckwheat. Oats don’t contain gluten (a protein found in wheat), but often they’re treated with it during processing. So if you’re allergic to wheat, be careful about eating oats too.
Sesame seeds are a typical food allergen and can cause problems for people who have allergies to peanuts or tree nuts. Many recipes call for sesame seeds, so it’s important to read ingredient labels carefully. Sesame is also a common ingredient in Asian cuisine, so it’s essential to be aware of it when eating out.
Celery is a vegetable that can cause problems for people with allergies to birch pollen. It’s one of the most common food allergens in Europe and the United States. Celery is found in many dishes, from salads to soups to stews. And it’s often used as a garnish. If you’re allergic to celery, be sure to read the ingredient list on all food products carefully.
Citrus fruits are a common cause of food allergies, especially in kids. These fruits include oranges, lemons, limes, grapefruits, and tangerines. Foods that contain citrus are often allergy triggers for kids with eczema, too.
Citrus fruits are acidic, so if you don’t do well eating them, the acid might also be contributing to inflammation in your body. If you’re allergic to citrus fruits, there isn’t any way to prevent cross-contamination. But always reading labels can help you avoid these foods when eating out or buying packaged products.
Strawberries contain salicylates (a type of aspirin) and can trigger symptoms in people with asthma. Strawberries are common food allergens and affect many kids who have allergies to birch pollen. They’re also one of the most common food allergens in kids with eczema. If you’re allergic to strawberries, you should always avoid them.
Soybeans are a type of legume, and they can cause problems in people who have allergies to peanuts or other legumes. Soy is found in many different products, so always check labels carefully. That’s especially true if you have a peanut allergy because soy is often processed with peanuts.
Mustard is a vegetable that can be problematic for people with allergies to mangoes, poison ivy, or latex. Mustard oil contains the chemical compounds known as essential mustard oils. It’s used in some foods and topical medication for muscle pain. If you’re allergic to mustard, avoid it in both forms.
14- green peas:
Green peas are legumes that can cause problems for people with allergies to peanuts or other legumes. They also contain salicylates, so you might need to avoid them if you experience asthma or hives. Green peas are often used as a thickener so that they might be an ingredient in canned soups and stews. Always read labels carefully before buying packaged foods or eating out at restaurants.