How allergies happen
Allergies happen when your child comes into contact with something in the environment that he's allergic to. This thing is called an allergen. It might be something that's harmless to most people, like food, dust mites or pollen.
The allergen enters the body and your child's immune system reacts to it. This reaction causes the release of histamine into the body, which leads to allergy symptoms.
Children who have family members with allergy problems like asthma, eczema, hayfever or food allergy are at increased risk of also developing allergy problems.Mild, moderate and even severe allergic reactions are common, but deaths from allergic reactions are rare. Deaths can happen when there's a delay in giving life-saving medication to the person having the reaction.
Allergic reactions: how quickly do they happen?
An immediate allergic reaction usually happens within minutes or up to 1-2 hours after your child comes into contact with or eats the substance that she's allergic to.
A delayed allergic reaction usually occurs between 2-4 hours and up to several days after your child comes into contact with the substance he's allergic to.
Mild or moderate allergic reactions: symptoms
If your child is having a mild or moderate allergic reaction, her symptoms might include one or more of the following:
- rash, hives or welts
- swelling of the face, eyes or lips
- tingling or itchy mouth
- eczema, hay fever or asthma - these symptoms might be worse than usual
- diarrhoea, stomach pain or vomiting.
Note that if your child has diarrhoea, stomach pain or vomiting after an insect sting, it means he's having a severe allergic reaction.
Severe allergic reaction or anaphylaxis: symptoms
A severe allergic reaction is called anaphylaxis. Symptoms might include one or more of the following:
- difficult or noisy breathing
- tongue and throat swelling or tightness
- trouble talking or a hoarse voice
- a wheeze or persistent cough
- persistent dizziness or fainting
- paleness and floppiness (in young children)
- low blood pressure
- diarrhoea, stomach pain or vomiting after an insect sting.
Testing for allergies
If you think your child might have allergies, getting a proper assessment is important.
To start this process, you can talk to your GP, who might refer you to an allergy or immunology specialist for the following tests:
- Skin-prick test: your child's skin is pricked with a small device that looks a bit like a toothpick and that contains a drop of a specific allergen. If your child is allergic, a red lump might come up where the skin has been pricked.
- Blood tests: the serum specific IgE antibody test uses your child's blood to see whether he's sensitive to specific allergens. Your child might have this test if he can't have skin-prick testing because he has severe eczema or has taken an antihistamine in the five days before the test.
Treatment for mild to moderate allergic reactions
The way you treat an allergic reaction depends on how severe the reaction is.
Giving your child a dose of antihistamine (in tablet or syrup form) is appropriate if you think your child is having a mild to moderate allergic reaction like a skin rash, tingling mouth or swelling.
In fact, having some antihistamine syrup in your home's first aid kit is a good idea - this way it's handy when you need it. You don't need a prescription to buy antihistamines in Australia.
Some antihistamines can make your child sleepy, which can look like anaphylaxis and make it hard to know what reaction your child is having. It's best to use antihistamine that won't make your child sleepy. Your pharmacist or GP can advise you on the most appropriate brand for your child.
Other treatments for allergies
Depending on the kind of allergic reaction your child has, she might need other treatments. For example:
- If your child has eczema, he might need corticosteroid ointments.
- If your child has hay fever, she might need corticosteroid nose sprays.
- If your child has asthma, he might need an inhaler like Ventolin® or Asmol®.
Your doctor can also give your child an ASCIA (Australasian Society of Clinical Immunology and Allergy) actionplan. The action plan usually includes important information on how to manage allergic reactions and which medications your child should use.
Children who have persistent and troublesome allergies to insect stings, house dust mites and grass pollen might have immunotherapy to reduce or get rid of their symptoms. Immunotherapy isn't currently used for food allergies.If your child has a food or insect sting allergy, it's especially important to control her asthma well. If your child has a severe asthma attack, call an ambulance immediately.
Treatment for anaphylaxis
Children at significant risk of anaphylaxis are often prescribed adrenaline auto-injectors - for example, EpiPen®.
If your child is prescribed an adrenaline auto-injector, it's important that both you and your child learn how and when to use it. Your child's adrenaline auto-injector should be easy to reach at all times. You can also teach others - family, friends, teachers and carers - how to use it.
It's also a good idea for your child to wear a medical bracelet to let other people know about his particular allergy.
Food allergy or food intolerance?
Food allergies are different from food intolerances.
Mild to moderate intolerance doesn't involve the immune system, but sometimes symptoms of mild or moderate food allergy look like the symptoms of food intolerance. It's essential that your child's food allergy is confirmed by an allergy or immunology specialist.Most children with allergies to egg, cow's milk and wheat outgrow their allergies as they get older. Peanut, treenut, fish and shellfish allergies are more likely to be lifelong.