According to the Center for Disease Control and Prevention, about six percent of children and four percent of teens and adults suffer from food allergy disease in the United States.

These bad food allergic reactions can produce symptoms that affect the skin, respiratory tract, gastrointestinal tract, and cardiovascular system. The symptoms can vary from mild to severe, sometimes even life-threatening.

Most food allergies are first diagnosed in children, but can also appear first time in teens and adults. The majority of the food allergy reactions in children are mild and stop appearing as the child grows up. However, allergies caused by peanut, tree nuts, seeds, and seafood tend to stay on and may last lifelong.

Food allergy and food intolerance

It is relevant to remember that food allergy is different from food intolerance. In food allergy, the allergy or hypersensitivity reaction is caused by the body’s auto immune system and can affect various organs of the body.

Food intolerance is caused due to the inability of the body to digest the food eaten. Its symptoms are limited to the digestive tract. Lactose intolerance is a form of food intolerance, in which the person cannot tolerate milk.

Food allergy causes

In food allergy, the auto immune system mistakes the proteins in the food for foreign harmful substances and produces IgE antibodies to fight the proteins. This is because these proteins are similar to those found in pollen, which is commonly responsible for causing allergies.

Repeated ingestion of the same foods can conjure up a lot of these antibodies and result in the release of a lot of histamine in the body. That is why the first time you eat an allergic food, your allergic reaction may be very mild.

The second time around, the reaction will be more severe. The severity will depend on various risk factors described below.

Such food proteins, which are present in pollen are found in fruits, vegetables, nuts, and spices. This type of food allergy is called oral allergy syndrome and can cause swelling in the throat and rarely even anaphylaxis.

Cooking the fruits and the vegetables will help to prevent this type of allergy

The top 10 common foods that cause allergic reactions

  1. Eggs
  2. Milk (especially cow’s milk)
  3. Seafood (fish, crustaceans, and shellfish)
  4. Peanuts
  5. Mustard
  6. Sesame
  7. Sulphites
  8. Soy
  9. Wheat
  10. Tree nuts (walnuts, cashew, pistachios, almonds, Brazil nuts)

The most common foods to give rise to allergy in children include:

  • Milk
  • Eggs
  • Peanuts

The most common foods to cause allergy in adults include:

  • Fruit and vegetable pollen (oral allergy syndrome)
  • Peanuts and tree nuts
  • Fish and shellfish

How do you know you have a food allergy? Symptoms

Food allergy symptoms can be mild, causing a little discomfort, while in some people, these side effects of food allergy can be serious, even life-threatening. This life-threatening allergic reaction is called anaphylaxis. However, they are not common.

The most common signs and symptoms of mild to moderate food allergy reactions due to you being  hypersensitive to a particular food include:

  • Skin rash due to food allergies are common and seen on the face, but can appear on any part of your body.
  • Itching, hives, or eczema on the skin
  • Tingling or itching in the mouth
  • Swelling of the face, lips, and tongue
  • Swelling of the throat causing a hoarse throat and trouble swallowing
  • Nasal congestion or trouble breathing
  • Pain in the abdomen, diarrhea
  • Nausea or vomiting
  • Dizziness, lightheadedness, or fainting

When do the food allergy symptoms begin to show and how long do they last?

Food allergy symptoms appear every time the person ingests the food, he or she is allergic to. Once the food is identified, he or she should avoid eating it. That is bad food for him though it may be his favorite.

The common food sensitivity reactions can show up in a few minutes after eating the allergic food or can appear within a span of two hours. Rarely, the symptoms may onset four to six hours after eating the food in which case it becomes difficult to associate the symptoms with food allergy and with the particular food.

In some cases, after the symptoms go away, they show up one to four hours later (or sometimes even longer). This second appearance of the reaction symptoms is called a biphasic reaction.

Symptoms generally go away within a few hours but can at times, last for days. The severity and the duration of the allergy reaction depend on the following factors:

  • How allergic the person is to the bad food, meaning how sensitive the person he is to it.
  • The amount of the food he has consumed
  • The form in which the food was consumed, meaning liquid or solid form
  • Alcohol intake makes the allergy worse
  • So does stress
  • Regular exercise decreases the severity and duration of the allergy because it increases the blood flow to various parts of the body. This helps to get rid of the allergic substance from the body. However, there is a severe allergic reaction called exercise-induced anaphylaxis in which some people suffer from anaphylaxis after physical activity such as any exercise or even an activity such as dancing or cleaning up the garden. This happens when the person has eaten the allergic food before the physical activity. Exercise acts as a trigger factor.

Symptoms of severe allergy reaction (anaphylaxis) due to food allergy

In some people, food allergies are known to cause serious symptoms, which can be life-threatening, if not treated promptly. This is known as anaphylaxis. People who are allergic to the drug penicillin can develop an anaphylactic shock after being injected with this drug.

Symptoms of anaphylaxis due to food or drug allergy include;

  • Tightening of airways
  • A swollen throat that makes breathing difficult
  • Anaphylactic shock causes a severe drop in blood pressure
  • Weak and fast pulse
  • Dizziness or loss of consciousness

Common foods that can trigger a severe allergic reaction (anaphylactic reaction):

  • Peanuts
  • Tree nuts
  • Wheat (in children)
  • Fish
  • Shellfish
  • Milk
  • Eggs

What factors increase your risk of food allergy?

  • Family history. If any member of your family, meaning a parent or sibling suffers from any sort of allergy, you are very prone to developing food allergy. That family member could be suffering from any type of allergy such as allergic rhinitis (hay fever), hives, eczema, or food allergy.
  • A history of food allergy in the past, especially as a child, will make you prone to suffer from it again in the future.
  • Age. Infants and young children are more prone to develop allergies, especially to milk, soy, wheat, and eggs.
  • Bronchial asthma. If you suffer from bronchial asthma, it is very likely that you will have an allergy to some foods. In such people, the symptoms of food allergy are likely to be severe.
  • Other types of allergy. If you are a victim of any other type of allergies such as skin allergy or hay fever, you are at a greater risk of developing a food allergy.
  • Vitamin D deficiency. According to a study published in the Journal of Pediatrics, infants who suffer from vitamin D deficiency are at an increased risk of suffering from food allergy than those who are vitamin D sufficient. For more information, go to