Allergy-Intolerance to food affects 1 in 4 people – that is 25% of the population.  Yes, food Allergy/ food intolerance is found in about 1 in 4 children as well.  However, most are not properly diagnosed or dealt with.  Patterns and symptoms of food allergy-intolerance change with age.

The problem is that most symptoms are just put up with.  Most of the symptoms of allergy/ intolerance are either ignored, or attributed to something else – such as “viral illness”, or being “naughty” or having a symptoms such as tummy ache, constipation, eczema or a runny nose that the child is just “expected to grow out of”.
But all sorts of symptoms can be caused by a food allergy.


Allergy-Intolerance Symptoms

Symptoms include:

  • Eczema
  • Urticaria (wheals, welts)
  • Poor health and run down
  • Runny nose and cough
  • Diarrhoea and/or constipation
  • Tummy pains, aches and colic
  • Irritability, tied, lethargy and cracky.
  • Gastric reflux, heart burn, regurgitation
  • Headaches and migraine
  • Behaviour disturbance
  • ADHD, ADHD (attention deficit disorder, sometimes with hyperactivity)
  • Autism

Two sorts of food reaction

Food reactions are usually classified by the timing of the symptoms. There are two main types of food reaction, classified by the timing of the symptoms. The slow onset food reactions are the most common, but also the most difficult to diagnose.

  • QUICK onset reactions
  • SLOW onset reactions.

Quick-onset food reactions

Quick reactions come on within a few minutes. Usually, a rash on the face and some swelling of the face occurs. Skin reactions (urticaria and eczema) are the most common symptoms. Some children will get choking and wheezing with larger amounts of food. These reactions are known as immediate IgE reactions.

Seeing a child with these symptoms is frightening. It might appear to be a life-threatening reaction. This is called an “anaphylactic reaction” (see: dealing with anaphylaxis). However, almost universally children quickly recover. A fatality from food allergy is an extremely rare event (see: death from food allergy).

The most common foods causing quick-onset food reactions are:

  • Eggs
  • Peanut
  • Cow’s milk
  • Soy
  • Wheat
  • Tree nuts
  • Fish
  • Shell fish
  • Sesame

However, many other foods can also cause this type of immediate reaction. Most children become tolerant to their “allergy” foods by school age. Skin prick testing is very helpful for diagnosis of immediate food allergy.

Slow-onset food reactions

Slow reactions to foods come on within a few hours, or even days. The symptoms are usually a gut reaction such as diarrhoea and vomiting. Also constipation, poor growth, abdominal pains and gastro-oesophageal reflux (GORD/ GERD) can be due to a slow-onset food reaction. This is sometimes called a food “intolerance”.

These sorts of food reaction are not driven by IgE (there are other immunological reactions at work). Therefore, skin prick testing (and EAST/RAST testing) is not helpful in the diagnosis of this types of reactions. In other words, people who have slow-onset reactions have negative skin prick tests.

The most common foods causing slow-onset reactions are:

  • Gluten
  • Cow’s milk
  • Soy

However, many other foods can cause this type of reaction.



If your child has chronic symptoms, then food allergy/intolerance could be the cause. Get this checked out. However, skin prick tests will only help identify the quick-onset reactions. Blood tests for gluten (gliadin) antibodies can help identify the gluten syndrome.

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