Common allergy foods

Babies and young children are affected by food allergies and intolerances because of their underdeveloped immune system (resulting in allergies), and the proportion of food chemicals they are exposed to in comparison to their body weight (resulting in intolerances).

  • Baby food allergies are relatively rare - it's estimated that up to 8% of babies under 12 months, 3% of children under five years old, and less than 1% of all adults suffer from a food allergy.
  • Baby food intolerance is much more common, and affects all age groups. Experts judge that approximately 10% of the population is affected by food intolerances.

Which foods are the most common allergens?

Usually people who suffer from food allergies react to one or two foods. What these foods actually are depends on repeated exposure to the sensitive foods, which means that different geographical areas have different common food allergens, depending on what the general population eats. In Japan, buckwheat is a common allergen, while lentils are a common allergen in Mediterranean countries.

90% of all food-allergic reactions in New Zealand are caused by eight foods. These are:

  • milk
  • egg
  • peanut
  • tree nuts (walnut, cashew, etc.)
  • fish
  • shellfish
  • soy
  • wheat

With food intolerance, it's the food chemicals that create the problem and the chemical you may be sensitive to could potentially be found in a wide range of foods. Some chemicals are naturally found in food - such as amines found in cheese, chocolate and wine - while others are added during processing to enhance the colour, flavour or shelf-life.

Food allergies and intolerances: how much is too much?

If you are allergic to a certain food, the tiniest amount of the allergen can be enough to set off a reaction. Some children are so sensitive to peanuts that they can become unwell just sitting near another child who is eating a peanut butter sandwich.

Intolerance reactions to food chemicals are dose-related and some people are more sensitive than others. In theory, everyone will react to food additives if they consume enough.

Symptoms of food allergies and intolerances:

Allergic reactions can cause:

  • itching
  • swelling
  • rash
  • hives
  • vomiting
  • diarrhoea
  • breathing difficulties
  • anaphylaxis, which can lead to collapse and death

Food intolerance reactions have the same reactions as above, but also involve the following:

  • respiratory system (stuffy or runny nose, asthma, frequent colds and infections)
  • gastrointestinal tract (irritable bowel symptoms, colic, bloating, diarrhoea, vomiting, frequent mouth ulcers, reflux, bedwetting)
  • central nervous system (migraines, headaches, anxiety, depression, lethargy, impairment of memory and concentration, panic attacks, irritability, restlessness, inattention, sleep disturbance, restless legs, moodswings, PMT).

Anaphylaxis: what is it?

Anaphylaxis is an allergic reaction that takes place in two of our body's systems (eg respiratory and gastrointestinal or skin). Anaphylactic deaths that result from an insect bite (bees) or drugs (penicillin) usually happen within minutes and are a result of cardiac arrest. Anaphylactic deaths that result from food allergies are usually a result of suffocation (respiratory difficulties).


Mild allergies may not need treatment, or might be OK with an over-the-counter pharmacy medicine. For more severe symptoms, your doctor may prescribe steroid medication or quick-acting inhaled bronchodilators and/or other medicine to treat breathing problems. Two types of treatment are:

Immunotherapy:  designed to make you less sensitive to an allergen so you don’t react to it so strongly. This involves injecting you with tiny but increasing amounts of the allergen. The treatment phase can last up to 6 months, followed by a maintenance phase for 2–3 years or longer.
Epi-pen emergency kits:  The epi-pen is a ready-to-use syringe of adrenaline prescribed by your doctor, which is essentially designed to keep you alive until you get to hospital. Teach family members, friends and work colleagues about how to use an epi-pen and make sure they know that you must also get to hospital straight away.

For more information on anaphylaxis, go to:

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This article was written by Ella Walsh for Kidspot - New Zealand's parenting resource for newborns and baby. Sources include SA Government's Parenting and Child Health, Karitane, and Ministry of Health NZ.

Last revised: Tuesday, 15 July 2014

This article contains general information only and is not intended to replace advice from a qualified health professional.