Food Allergy: Causes, Symptoms, Common Allergic Foods, Risk Factors

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, the respiratory tract, the gastrointestinal tract and the cardiovascular system. And, the symptoms can vary from being 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 nut, seed and seafood tend to stay on and may last life long.

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, where the person cannot tolerate milk.

Food allergy causes

In food allergy, the auto immune system mistakes the proteins in the food eaten, 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 are commonly responsible for causing allergy.

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 poolen 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 allergy 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 food allergy? Symptoms of common mild food allergy reactions

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 allergy reaction is called anaphylaxis. However, they are not common.

The most commonly seen signs and symptoms of mild to moderate food allergy reactions due to you being hypersensitivity to a particular food include:

  • Skin rash due to food allergy 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 throat causing a hoarse throat and trouble swallowing
  • Nasal congestion or trouble breathing
  • Pain in the abdomen, diarrhea
  • Nausea or vomiting
  • Dizziness, light headedness 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 b 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 is to the food eaten
  • 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 allergy or drug allergy include;

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

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

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

What factors increase your risk to 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 develop food allergy. That family member could be suffering from any type of allergy such as allergic rhinitis (hay fever), hives, eczema, or food allergy.
  • History of food allergy in the past, especially as a child, will make you prone to suffer from it again the future.
  • Age. Infants and young children are more prone to develop allergy 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 allergy such as skin allergy or hay fever, you at a greater risk of developing 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 www.vitamindcouncil.org
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