If you don’t have an allergy, you probably know someone who does. It seems that increasingly allergies are being identified and more of us diagnosed with some sort of allergy. Some of these are potentially fatal while others may cause irritations and minor symptoms.
At Port Melbourne Medical we manage a broad spectrum of these conditions for our patients on often refer to specialists in the area. We are delighted to have Dr Dean Tey, Paediatric Allergist, as this newsletters guest author in a topic that’s getting more and more attention and discussion in the practice.
Dr Dean Tey
Phone: 03 9345 6888
Fax: 03 8374 3860
Melbourne has the highest reported rates of food allergy in the world, with approximately 9% of 1-year-old children with an egg allergy, and 3% with a peanut allergy. Majority of food allergies (95%) are caused by allergies towards milk, egg, wheat, soy, peanuts, tree nuts, fish and shellfish. The good news is that most children with milk, egg, wheat and soy allergies outgrow their allergies by older childhood, whilst 10-20% of children outgrow nut and seafood allergies by adulthood.
What are the different types of food allergy?
Food allergy can be either IgE-mediated (immediate) or non-IgE mediated (delayed). Symptoms of IgE mediated food allergy typically occur within 1-2 hours of ingesting a small amount of culprit food, can be confirmed on allergy testing with skin prick or blood allergy testing, and carries the risk of anaphylaxis. In contrast, non IgE mediated food allergy typically involve delayed symptoms of vomiting and diarrhoea, typically a few hours after ingesting the food, and there is no role for skin prick or blood allergy testing. The rest of this article will be about IgE mediated food allergies.
What are the typical signs of a food allergy?
The classical history of IgE mediated food allergy are symptoms which occur within 1-2 hours of eating the food protein. Your child may have one or more symptoms in the following categories: skin (hives, swelling), gut (tummy pain, vomiting, diarrhoea), respiratory (difficulty breathing, continuous coughing, tightness of the throat, wheezing, noisy breath sounds) or cardiovascular (dizziness or collapse, or pale & floppy in young children). Anaphylaxis is defined as having either respiratory or cardiovascular symptoms during a food allergic reaction.
How do we diagnose allergies?
Skin prick testing and blood allergy testing, combined with a classical symptoms of an allergic reaction, is the best way to accurately diagnose food allergies. In general, a high skin prick or blood allergy test tells us how confident we can be that your child has IgE mediated food allergy. Importantly, severity of reactions are not predicted by high skin prick or blood test results. Skin prick tests are usually repeated every 1-2 years. If the results are decreasing over time, this may indicate that your child is outgrowing their food allergy, and your child may be able to include the food back into their diet again. If there is a risk of an anaphylactic reaction, your specialist may recommend that this is done in a safe setting through an oral food challenge test under medical supervision.
How do we manage food allergies?
The key to good food allergy management is, initially, an accurate diagnosis of food allergy by your specialist, followed by avoidance of the food through label reading. Your specialist will discuss if your child will need an adrenaline autoinjector (EpiPen), which is usually recommended if your child has already had an anaphylactic reaction, or strongly considered if your child had troublesome asthma, or about to travel to a remote area. We also want to ensure that the rest of your child’s allergies are well-controlled, because having troublesome asthma, hayfever and eczema, can increased the risk of severe food allergic reactions. Each child should have a green allergy or red anaphylaxis action plan, with or without an adrenaline autoinjector, in childcare or at school.
How do we reduce the risk food allergies?
The Australasian Society for Clinical Immunology and Allergy (ASCIA) have the following recommendations for reducing the risk of food allergy in children:
- During pregnancy, we recommend a healthy balanced diet, rich in fibre, vegetables and fruit. Up to three serves of oily fish per week may be beneficial in reducing the risk of eczema in the baby.
- Breastfeeding, where possible, for at least six months, particularly when solids are introduced to the infants, may help reduce the risk of food allergy.
- Introduce solids when your infant is ready, at around 6 months, but not before 4 months, while continuing breastfeeding if you’re able.
- All infants should aim to have allergenic solids introduced in the first year of life, including cooked egg, peanut butter, cow’s milk and wheat products.
Want more information?
There are great resources and articles on the ASCIA website at www.allergy.org.au