Allergy, defined:
Allergy is defined as an overreaction of the immune system to a food or substance in the environment (called an allergen), which would be otherwise harmless to most people.
The body recognises the allergen as a threat, and produces antibodies (called IgE) to ‘remember’ the allergen – similar to how the body fights off a virus.
In an allergic reaction, the antibodies recognise the allergen and trigger the immune system to react.
Common Allergens
The most common childhood allergens you are likely to see include:
- Foods
- Grass/tree pollens
- Dust mites
- Mould
- Animal dander
- Medication
- Latex
- Venom
Food Allergy and Intolerance
Many of the patients we see either have an allergy or an intolerance to at least one, if not multiple foods. This page will identify the most common food allergens, along with some general information on management to help you along the way.
Common Food Allergens:
Almost any food can cause an allergic reaction, but there are certain foods that are much more common than others.
In Europe, food allergens are monitored and assessed by the European Food Safety Agency (EFSA). The current EU regulation is that the following fourteen food allergens must be listed on all food packaging, if present in the food. Below is a list of the fourteen food allergens – some of the items on this list contain links to some information about the allergies. Please click on the links for more information about specific food allergies.
- Fish
- Soybeans (soy, soya)
- Nuts (including almonds, Brazil nuts, cashews, hazelnuts, Macadamia, pecan, pistachio, walnuts)
- Celery & celeriac
- Mustard
- Sesame
- Sulphur dioxide (sometimes used as a preservative in dried fruit, sometimes referred to as sulphites)
- Lupin
- Molluscs (such as oysters, mussels, clams, whelks and squid)
Types of food allergy:
Food allergy falls into two different categories; IgE mediated and non-IgE mediated allergies.
IgE Mediated Food Allergy
This is the most common type of food allergy, and is triggered by the immune system creating antibodies called immunoglobulin-E, or IgE. Symptoms often occur within minutes, although can take 1 to 2 hours to appear. There is a greater risk of an anaphylactic reaction in this type of response.
Non IgE Mediated Food Allergy
These types of food allergies are not triggered by the immune system, but by other cells. These types of allergic reaction often take several hours to appear, and symptoms tend to be gut (stomach cramps, loose stools, colic) or eczema symptoms.
Symptoms of an Allergic Reaction
When people have allergic reactions, their symptoms can range from mild/moderate, to severe. The symptoms of each category are listed below.
Mild – Moderate Allergic Reaction
- Swelling of the lips, eyes or face
- Itchy/tingly lips or mouth
- Hives (itchy nettle-sting type rash)
- Nausea/vomiting
- Sneezing/sniffling
These types of allergic reaction are often managed with an oral antihistamine. It is recommended that you stay with your child following this reaction. We suggest avoiding any vigorous activity for the rest of the day following the allergic reaction. The reason for this is that vigorous activity has the potential to cause a second flare-up of the allergic reaction.
Severe Allergic Reaction (Anaphylaxis)
- Swelling of the tongue or throat
- Noisy breathing
- Hoarse voice
- Coughing and/or wheezing
- Pale and/or floppy/sleepy
- Collapse and/or unconsciousness
These types of allergic reaction have the potential to be life threatening and must therefore be treated as an emergency. You must dial 999 immediately. We also recommend lying your child flat, or sitting them down.
If your child carries an adrenaline auto-injector pen (EpiPen/Emerade/Jext), give this as per instructions and then dial 999.