Recognising food reactions

If your child has an adverse reaction after eating a particular food, how can you tell if it’s a food allergy or an intolerance?

Food allergies in children

Food allergy is an immunological response, usually to a specific protein in a food. It commonly occurs in early childhood and will affect around 1 in 20 children. The good news is that food allergy is usually outgrown, with the incidence in adulthood significantly lower and usually confined to nuts and seafood.

The most common food allergies seen in children are: cow’s milk protein, egg, peanut, tree nut, wheat and soy. Symptoms generally occur immediately and may include vomiting, diarrhoea, eczema, hives, asthma and anaphylaxis (see our article Living with allergies). Children most at risk of food allergy are those with a strong family history of asthma, eczema, hay fever and food allergy.

Skin Prick Testing (SPT) is the primary way to diagnose food allergy. However, to avoid the risk of misinterpretation, SPTs must be carried out by experienced medical practitioners in a medical facility equipped to treat anaphylaxis. For more, see our article Survival guide to food allergies and intolerances).

Food intolerances in children

Food intolerance is much more common than food allergy and can occur at any age. A food intolerance does not involve the immune system, rather it may be an irritation of nerve endings in different parts of the body that leads to reactions. It can be a reaction to naturally-occurring food components like salicylates, amines or glutamates, or to a common food additive (see list, below).

Symptoms of food intolerance are often delayed and quite varied, which can make identification a difficult and complex process. However, elimination diets can be a safe and effective tool in diagnosis, as long as they are conducted under the supervision of an experienced dietitian. SPTs and blood tests are not capable of diagnosing food intolerance.

Unlike with food allergy, complete avoidance of the culprit food component is rarely necessary. Often, low (and sometimes moderate) content foods can be carefully incorporated into the diet. If you suspect a food intolerance, consult a dietitian specialising in food intolerances (www.daa.asn.au).

Food additives and children’s behaviour

A small amount of additives won’t impact the behaviour of most children, but some will have an allergic or behavioural reaction. If you are at all concerned about your child’s reaction after eating a certain packaged food, it’s important to see a specialist who will be able to identify exactly which additive your child is sensitive to.

In general, when buying packaged foods, choose food products that contain the least amount of additives. Look for foods that have all-natural colours and flavours and minimal or no preservatives. It’s also important to choose foods that have a minimal amount of fats (saturated and trans), sugars and salt.

Food additives to watch for

The following list from The Royal Prince Alfred Hospital’s (RPAH) Allergy Unit includes some of the food additives most likely to cause adverse reactions, but is not exhaustive.

Colours

Artificial: 102, 107, 110, 122–129, 132, 133, 142, 151
Natural: 160B (annatto)

Preservatives

Sorbates: 200–203
Benzoates: 210–218
Sulphites: 220–228
Nitrates, nitrites: 249–252
Propionates: 280–283
Antioxidants: 310–312, 319–321

Flavour enhancers

Glutamates (e.g. MSG): 620–625
Other flavour enhancers and modifiers: 627–637, 640–641
Hydrolysed vegetable protein (HVP): Can contain MSG
Textured vegetable protein (TVP): Can contain MSG

For more information on food allergy, intolerance and additives, visit the RPAH’s Allergy Unit website at www.sswahs.nsw.gov.au/rpa/allergy/