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The Most Common Food Allergies

Food allergies can cause a number of reactions - find out what the most common food allergies are, how to treat them and how to avoid a reaction.

Food allergies can cause a number of reactions - find out what the most common food allergies are, how to treat them and how to avoid a reaction.

These days it seems like everyone has some sort of food issue. Vegan, gluten free, casein free, dairy free, egg free, vegetarian, pescatarian, no nuts, kill the carbs, high fat, low fat, macrobiotic, organic, paleo – you name it, there’s a diet for it. A lot of these diets are based on preferences, however, some people have food issues they have no choice about.

Food Allergies and Food Intolerances occur when a person has a sensitivity to a particular food or foods, however, each occur for different reasons.

What Is A Food Allergy?

A food allergy is an adverse immune response where a person reacts to a component of the food, most commonly the protein. These food allergies occur because the body’s immune system identifies this particular protein as harmful, fooling the immune system into thinking the body is under attack – thus causing an allergic reaction.

Symptoms of an Allergic Reaction

An allergic reaction can range from mild to life threatening and the symptoms can be life threatening such as anaphylactic responses including biphasic anaphylaxis (where the body reacts in two phases which causes a second reaction randomly after the initial reaction has long subsided) and vasodilation (which causes the blood vessels to widen, decreasing blood pressure and causing shock).

People with food allergies need to avoid contact with the problem proteins and sometimes medications are prescribed to prevent, minimize or treat protein allergy reactions.

Food allergies present symptoms such as:

  • itching and burning around the mouth
  • swelling of the mouth and tongue
  • runny or stuffy nose
  • skin reactions (such as hives and rashes)
  • vomiting
  • nausea
  • wheezing
  • itching, burning and watering of the eyes
  • swelling of the throat
  • stomach pains and cramps
  • stomach upset
  • irritability
  • fatigue
  • convulsions and tremors

What is the Difference Between a Food Allergy and An Intolerance?

Whilst a food intolerance reaction presents symptoms that are similar to a food allergy, they are completely different. A food intolerance is a hypersensitivity to a certain food or compound found within a range of foods, it is not an allergic reaction as it is often mistaken to be.

How Common Are Food Allergies?

Whilst many people feel they have food allergies, they are often only food intolerances. The incidence of food allergies is quite small with 1 in 20 children and 1 in 100 adults being diagnosed with a food allergy.

In the present day, allergies and intolerances have been seen to be on the increase across the globe. They can occur in people of all ages, however, most children will grow out of their food allergies before they reach school age.

The Most Common Food Allergies

90% of all food allergies are caused by four main foods – nuts, eggs, milk and soy. In older children, peanut allergies are the most common whilst cow’s milk is the most common food allergy in early childhood.

The foods that most commonly produce allergic reactions include:

  • Eggs
  • Milk
  • Soy
  • Peanuts
  • Other nuts
  • Sesame
  • Gluten
  • Fish
  • Grains such as rye, wheat and oats
  • Sea mollusks such as oysters, clam, squid, octopus and mussels
  • Crustaceans such as crab, prawns, shrimp and lobster
  • Fruit, berries, tomato, cucumber, white potato and/or mustard (most commonly cause issues as a group due to a particular protein within each food).
  • Food additives and preservatives such as sulphites, salicylates, benzoates and MSG

Diagnosing a Food Allergy

In some people, an allergic reaction will occur within minutes, making it easy to pinpoint the particular food causing the problem. For other people, the cause is unknown and the symptoms are delayed, making it tricky to find which food or foods are the problem – in this situation, diagnostic tests may be needed.

The diagnostic tests used to find food allergies include:

  • Elimination Diets
    Where all suspects foods are removed for a period of two or more weeks before they are then reintroduced one at a time in order to test for a reaction. This is not done in cases of anaphylaxis and should also be conducted under medical supervision and guidance
  • Food and Symptoms Diary
    By keeping a diary of all food consumed throughout the day and the symptoms experienced, patterns can be identified between eating certain foods and experiencing particular reactions.
  • Skin Prick Tests
    During a skin prick test, drops of specific food extracts are placed onto the skin and the skin is then pricked with a small needle in order to expose the body to these extracts. The patient then stays still for 20 or so minutes and is observed for any adverse reactions. If the skin comes up in welts or red spots, these areas are then examined to see if they are indeed a reaction to the particular extract.
  • Blood Tests
    A common blood test used to determine food allergies is a RAST test. A RAST test is short for radioallergosorbent test, which determines what substances a person is allergic to.

How To Treat Food Allergies

For people with food allergies, the best way to treat them is by eliminating it from the diet and avoiding the food wherever possible. It is common for people who have avoided particular problem foods for a period of time to have no reaction later on when reintroducing the food in small doses - however, many with food allergies will need to avoid those foods for their entire lives (such as those with celiac disease). This is why it's important to know what foods to avoid with food allergies.

To protect your child from food allergies in the future, it has been advised to breastfeed exclusively for the first four to six months in order to protect against the development of early childhood allergies. Medical experts have also found that should a baby be found to be allergic to a particular food, the breastfeeding mother should avoiding eating that food throughout the duration of the breastfeeding period.

Early exposure to cigarette smoke and introducing solid foods to your child earlier than recommended has also been seen to increase the risk of developing early childhood allergies.

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