What is a food allergy?

Food allergies can be hereditary — that is, parents can pass the likelihood of developing a food allergy to their children through genes that code for inherited traits.
But this doesn't mean that an allergy to a particular food will be passed down or that everyone with food allergies inherits it from their parents.
A food allergy is a condition that causes your immune system to fight against a particular part of food — which is called an allergen. Though most food allergens are proteins found in natural foods, some individuals may develop allergies to food additives.
Death due to a food allergy is rare — but possible. A food allergy can sometimes cause anaphylaxis — which is a severe allergic reaction that causes breathing difficulties. In such cases, emergency treatment with a medicine called epinephrine could be life-saving.
What are the most common food allergies?
Though there are many allergy-causing — or allergenic — foods, these are some of the most common foods that can cause reactions:
- Cow’s milk
- Tree nuts — almonds, pecans, walnuts, etc.
- Shellfish — crab, lobster, shrimp, etc.
- Soy
- Eggs
- Fish
- Wheat
- Peanuts
In some cases, cross-contamination may happen during food processing, which can cause an allergen to appear in a food that otherwise does not lead to a reaction.
Many companies label foods that may have cross-contamination with allergens as a courtesy to the consumer. If a product is labeled “may contain …” or “manufactured/packaged in a factory that also processes …,” the product may be cross-contaminated with the specified allergens.
What are common allergic reactions?
Common allergic reactions include:
- Vomiting
- Hives
- Breathing problems
- Stomach ache
Common myths and misconceptions about food allergies
People often have conflicting opinions concerning food allergies. So, it’s common to hear, and even believe, myths and misconceptions about the topic.
Once allergic, always allergic
This myth is not true for all people. For example, it’s common for children to outgrow milk and egg allergies. However, if you’re allergic to fish and shellfish, chances are that you’ll remain so for the rest of your life. Fish and shellfish are in different food groups, so being allergic to one group doesn't mean that you would be allergic to the other.
Eating a little of an allergen can beat the reaction in the long run
Some people think that it’s possible to train their body not to see a certain food as an allergen, and with time, recover from an allergy completely. The only safe way to consume food that you are allergic to is with careful monitoring by your doctor so as to prevent serious allergic reactions.
Wheat allergy can lead to celiac disease
Wheat and other cereal grains like rye and barley contain gluten — a protein that can cause an immune reaction leading to a disorder known as celiac disease. However, celiac disease and gluten or wheat allergy are two separate conditions.
Food allergies can be fatal
Serious food allergies can be fatal. Call 911 right away if you notice the following symptoms after eating any food:
- Difficulty breathing
- Feeling like your throat is shutting
- Swelling in your lips, tongue, or throat
- Hoarseness in your voice
- Trouble speaking
- Change to the heartbeat
- Seizures
- Feeling light-headed
- Skin cooling
- Loss of consciousness
- Dizziness
How do food intolerance and food sensitivities differ from food allergies?
You may experience some discomfort after eating certain foods, but that doesn’t mean you are allergic to them.
Food intolerance or sensitivity is not as serious as food allergy. Intolerance — which is mainly related to the digestive system — happens when the system can’t digest or absorb a certain food or some of its parts. As a result, you may have symptoms like abdominal pain, bloating, diarrhea, and flatulence.
A food allergy, on the other hand, involves the immune system. When you’re allergic to a certain food, your immune system produces an antibody called immunoglobulin E — or IgE. IgE then signals for the release of chemicals that cause the symptoms of an allergic reaction — ranging anywhere between mild and fatal in intensity.
For some people, telling the difference between symptoms of food intolerance and food allergy may be difficult. Food sensitivity includes intolerance, and chemical sensitiveness toward natural chemicals like caffeine, tyramine (found in aged cheese), and monosodium glutamate (used as a flavor enhancer).
What are ways to cope with a food allergy?
If you suspect that you are allergic to a certain food, consult your doctor. They will conduct some tests and advise you accordingly.
Once it’s confirmed that you should not consume or come into contact with specific foods, your doctor will advise you regarding what you cannot safely eat. Afterward, it’ll be important for you to always check food labels so that you can avoid eating what you shouldn’t.
In the case of children, it’s important for their school staff and caretakers to know what they shouldn’t eat and what to do in an emergency.
A person having an allergic reaction needs immediate medical attention. Even if first-aid or epinephrine has been given, always call the doctor.

QUESTION
Allergies can best be described as: See AnswerHealth Solutions From Our Sponsors
American Academy of Family Physicians: "Myths and Facts About Food Allergies."
Canada.ca: "Food Allergies and Intolerances."
Cedars-Sinai: "Food Allergy Myths and Facts."
Food Allergy Research & Education: "Food Allergy Myths and Misconceptions."
Gastrointestinal Society: "10 Myths about Food Allergies."
The Nemours Foundation: "All About Allergies."
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