By Raising Children Network
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Girl drinking from a glass of milk
If your child has food allergies or food intolerance, it’s very important for your child to avoid the food. You also need to know how to spot the symptoms and manage a reaction.

Food allergies: symptoms

A food allergy is a response by the body’s immune system to a particular food. The immune system responds to the food as if it were toxic.

Food allergies can occur immediately (immediate onset) or after some time has passed (delayed onset).

The symptoms of immediate-onset food allergies appear between a few minutes to three hours after a child has come into contact with the food.

Symptoms of immediate-onset food allergies include:

  • skin reactions, such as redness, hives or dermatitis
  • itchy mouth or eyes
  • vomiting, stomach pain or diarrhoea
  • nasal congestion
  • swollen lips or tongue, which can constrict airways and make it hard to breathe
  • swollen face, including swelling of eyelids and face
  • anaphylaxis, or anaphylactic shock, which is a severe and life-threatening reaction. A child might have a persistent cough, wheezing, hoarse voice, shortness of breath and difficulty swallowing. The child might even pass out.

The symptoms of delayed-onset food allergies appear more than four hours after a child comes into contact with the food and sometimes many days later.

Symptoms of delayed-onset food allergies include vomiting, diarrhoea and stomach cramps.

Food intolerances: symptoms

A food intolerance is a reaction in your body, caused by a substance in the food you’re eating. It is not caused by your immune system responding to the food. It often has a delayed onset.

Symptoms of food intolerance appear up to two days after exposure. They can include constipation, diarrhoea and stomach pain. They can also include skin redness and dermatitis.

What to do about food allergies

There is no cure for food allergies. Many children grow out of them though. You can also take some steps to make it easier for you and your child to live with food allergies.

Avoid the food
It’s important to avoid the food. This can be challenging, particularly if eating even tiny amounts causes a reaction. Your child also needs to avoid any foods or cutlery that could have been in contact with the food she’s allergic to.

You can do two important things to help your child avoid the food:

  • Read labels on all foods. Be aware that some allergenic foods have different names, such as ‘whey’ or ‘casein’ for cow’s milk protein. By law, the 10 most common allergens need to be stated on food labels.
  • Be careful when you eat out. Ask what ingredients each dish includes, how it was prepared, whether it has touched any other foods, and whether there is any risk of cross-contamination. Most restaurants are happy to tell you, but they might not know about the ingredients of some of their foods, such as sauces.
It’s best to avoid buffets and bain-maries (food warmers) because there is a good chance ingredients have been transferred from one dish to another.

Have an emergency plan
You should talk to your doctor about an emergency plan. This will help you recognise and treat symptoms if your child eats something that causes an allergic reaction.

  • Your doctor might suggest your child wears a medical bracelet that explains his allergy.
  • If your child’s allergy carries a risk of anaphylaxis, you might be prescribed a device called an EpiPen®, which makes it easy to self-inject adrenaline. Your doctor will teach you and your child (if old enough) how to use the EpiPen®.
  • It’s important that key people – such as family, carers, babysitters and your child’s school – know about your child’s EpiPen® and how to use it correctly.

What to do about food intolerances

Symptoms of food intolerance are usually less severe than those of allergies.

If a doctor has diagnosed food intolerance in your child and your child eats something you know she’s intolerant of, she shouldn’t need medical attention. The symptoms will usually clear up by themselves. If your child’s symptoms include diarrhoea, you need to ensure she gets plenty of water.

If you’re not sure why your child is having a reaction, and there is a possibility the reaction could be caused by a food allergy, it’s best to consult your doctor.

Diagnosing food allergies and intolerances

If you think your child has a food allergy or intolerance, your GP is the best place to start. Your GP might refer you to an allergist, who might do further tests.

Immediate-onset food allergies
Tests for immediate-onset allergies include the following:

  • Skin-prick test (SPT): the allergist will put a small amount of the possible allergy-causing substance on your child’s skin. Then the allergist will prick your child’s skin with a small toothpick-like device. A red lump might come up where the skin has been pricked. Your child’s allergist will talk you through the results of this test.
  • Blood tests: the allergist might use the RAST (radio allegro sorbent test) to see whether a substance called IgE is in your child’s blood. Blood will usually be taken from your child’s arm, and sent away for testing.
  • Elimination diet: this involves removing possible allergy-causing foods from your child’s diet, then reintroducing them again if the allergist thinks it’s safe to do so. Your allergist is looking to see whether your child’s symptoms flare up when the foods are put back into the diet.
  • Oral food challenge: your child will be given the possible allergy-causing food to eat in a safe, supervised setting. Medical and nursing staff will watch to see whether an allergic reaction occurs. This test carries a risk of causing a severe allergic reaction and should be conducted only by a specialist in a supervised setting.

Delayed-onset food allergies
If your child has a delayed-onset allergy, testing is more difficult. The most commonly used test is an elimination diet.

A new test, called the food patch test, is being trialled. This involves putting a patch with an extract of the possible allergen on your child’s skin to see whether dermatitis develops.

Food intolerances
Elimination diets are also the most common test for food intolerances.

For suspected fructose or lactose intolerance, doctors might also use a breath test. This tests the amount of hydrogen gas in the child’s breath. Lactose-intolerant children will have higher levels of hydrogen in their breath.

  • Last updated or reviewed 11-12-2014