Food Allergy Testing and Diagnosing
On this page: What to do is you suspect you have a food allergy Testing for a food allergy Types...
Information on symptoms, diagnosing and testing, egg allergy and vaccinations and breast feeding and egg allergy.
On this page: What to do is you suspect you have a food allergy Testing for a food allergy Types...
Eczema (also called atopic eczema or atopic dermatitis) is a very common non contagious dry skin condition affecting approx. 1in...
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Eggs are one of the most common foods to trigger allergic symptoms in babies and young children. Most children with an egg allergy will start to outgrow it by the time they go to school but in some it will persist into later childhood or in rare cases, adulthood. Egg allergy can occasionally develop in adult life.
Reactions to egg are usually triggered by the protein part of the egg (mainly in the egg white). Babies who have eczema are at an increased likelihood of developing an egg allergy. Having another type of food allergy for example to cow’s milk or a family history of allergy (atopy) also increases the risk.
Allergic reactions to egg can be mild, moderate or severe (anaphylaxis). There are certain things that affect how severe an allergic reaction may be, including the amount of egg eaten, and how well the egg was cooked.
Egg does not have to be eaten to cause an allergic reaction, coming into contact with eggshells or touching (raw) egg can cause allergic symptoms usually affecting just the skin in highly sensitive individuals.
Most reactions to egg are mild and symptoms are seen soon after eating egg or foods containing egg. Babies will often show reluctance or refuse to eat the egg. If egg comes into contact with the skin around the mouth it can cause a local reaction which is seen as a rash and may include redness and raised red bumps that are called hives.
Other allergic symptoms affecting the skin include swelling to the lips, eyes and face. The stomach may also be affected and vomiting is common as well as stomach ache/cramps and loose stools (diarrhoea). Egg allergy can also cause eczema flares. Severe (anaphylaxis) allergic reactions to egg are less common but possible and affect the breathing and may be seen as a cough, noisy breathing (wheeze) and circulation which results in them becoming pale and floppy babies and small children) or older children and adults who feel dizzy and may lose consciousness. Severe allergic reactions are a medical emergency, and an ambulance should be called immediately. More information on anaphylaxis can be found in the following factsheet: Anaphylaxis and Severe allergic reactions.
Small amounts of egg protein may be passed through mother’s milk during breastfeeding. If the infant has no symptoms the mother can continue eating egg. However, if the infant has any gut or skin symptoms such as eczema, they may benefit from the mother trialling excluding egg from her diet. If there is no improvement in symptoms after 2 weeks, eggs can be reintroduced back into the mother’s diet.
If you suspect that you or your child may have an egg allergy, it is important to discuss this with a health professional. This will normally be your GP or Health visitor who can offer further advice and recommend if allergy testing is needed. Allergy testing for egg can be done by a blood test and/or a skin prick test. The availability of access to these tests will vary from and may require referral to an allergy specialist for the testing and further management. Sometimes a diagnosis is made on the clinical history alone.
Some people with an egg allergy can eat egg that has been well cooked (for example egg as an ingredient in a cake) and will only develop allergic symptoms if they eat loosely cooked egg (for example scrambled egg) or raw egg (e.g. fresh mayonnaise or chocolate mousse). This is because the structure of the egg protein is changed by heat from cooking which makes it less likely to cause allergic symptoms. Around 80% of people with an egg allergy can tolerate a well baked egg in a cake.
Therefore not all people with an egg allergy need to avoid all forms of egg and this should be decided on an individual basis. It will depend on the severity of previous allergic reactions and the results of allergy testing. Your GP or allergy specialist should provide information on whether all forms of egg need to be avoided. In those who are allergic to well-cooked egg, the reactions may be severe and strict avoidance of all egg and egg containing foods is necessary.
Where children have had mild to moderate reactions to egg they may be asked to re-introduce egg into the diet at home. Children who have had a severe reaction to egg in the past should not be given egg at home in any form until advised by a health professional – and then this is usually only done in hospital under supervision as a well baked egg challenge test where staff are trained to recognise and treat symptoms of allergic reaction should it occur.
The influenza (flu) and yellow fever vaccine are made by growing the vaccine in chicken eggs and small amounts of the protein can remain in the vaccine.
The flu vaccine is part of the UK immunisation schedule for babies over 6 months, adults over 65 and those considered to be at high risk including those with asthma requiring continuous use of inhaled or oral steroid treatment. (NICE Guidelines on seasonal influenza). Yellow fever is a travel vaccine given to those visiting high risk areas, so it is only required if traveling overseas to high risk areas.
Extra caution should be taken for those with a severe egg allergy that have required admission to intensive care for severe anaphylaxis to egg or have severe asthma or active wheezing or required recent oral steroids for their asthma -as it is possible to react to vaccines containing small amounts of egg protein (although this is very rare). In this case a referral to an allergy specialist for assessment on the risk versus benefit of receiving the flu vaccine to help decide whether the vaccine is needed and how and where the vaccine is to be given. (BNF- 2017-2018 Children Vaccination section).
Where there has been a confirmed anaphylactic reaction to a previous dose of the flu vaccine or a confirmed anaphylactic reaction to any part of the vaccine other that (Ovalbumin) the vaccine should NOT be given.
The measles, mumps and rubella vaccine (MMR) can be safely given to all children with egg allergy even those that have had anaphylaxis. Sometimes it is developed on chick embryo cell cultures (not chicken egg) but is considered safe for egg allergic children to have. (Reference source: BSACI Egg Allergy Guidelines and the BNF 2017-2018).
This is only a guide. Do please check ingredients to ensure that you are:
It is easy to avoid eggs that are served on their own when they look like an egg; however they are often hidden in prepared and manufactured foods so beware.
It was previously suggested that raw and loosely cooked forma of egg should be avoided due to the risk of salmonella food poisoning to vulnerable groups of salmonella. Changes in advice from the foods standard agency (October 2017) have resulted in the advice that eggs that are produced under the British Lion Code of practice ( which is identifiable from the egg carton/box) can be safely eaten in raw or lightly cooked forms by (babies, infants, pregnant women, and elderly persons). However if you are egg allergic you should only eat egg in the form you tolerate.
In the European Union (EU) ingredients lists on food labels must clearly emphasise (for example in bold or highlighted) whether they contain any of the 14 most common allergens. One of these 14 foods that must be labelled is EGG
Outside of the EU food labelling laws will be different it is important to check ingredients carefully, especially where food has been imported from outside of the EU or when eating out whilst on holiday.
INGREDIENTS: Rapeseed Oil (78%), Water, Pasteurised Free Range Egg & Egg Yolk (7.9%), Spirit Vinegar, Salt, Sugar, Sunflower Oil, Lemon Juice Concentrate, Antioxidant (Calcium Disodium EDTA), Flavourings, Paprika Extract
Businesses selling food are required by EU law to provide information on allergens within food. Therefore don’t be afraid to ask what ingredients a food contains, as it is not always clear from menu descriptions.
It is important to highlight your egg allergy and request that people cooking and handling food are cautious and avoid cross contamination. It is also helpful to telephone places you are planning to visit before you go to make sure they can cater for your dietary needs.
When eating away from home with a food allergy, allergy medication should always be taken with you or on behalf of a child in case of an accidental exposure which commonly happens when eating outside of the home. In fact even if you are not planning to eat you should always have your allergy rescue medications available.
Allergy UK are able to provide a translation card service which can be used when travelling or eating out abroad. (These are available in multiple languages at a small cost from Allergy UK’s helpline (01322 619898). These cards have English on one side and the translated food allergen(s) in the language required on the other.
They can also be used in the UK as a card written in English with the allergens you need to avoid, this can save a lot of time and prevent mistakes being made in translation, and showing the card makes sure the seriousness is understood. These cards are the size of a credit card and can easily be stored in a purse, wallet or pocket.
These can be identified by reading the ingredients label. By law cosmetics, toiletries, perfumes and medications include a list of ingredients on their packaging. Where the labelling is in Latin, the words you need to look for are OVUM or OVO. However only avoid these if they caused irritation – they are often not a problem.
These usually have little or no nutritional value but are useful in cooking. Whole egg replacers and egg white replacers can be purchased from your pharmacist, health food shop and in most supermarkets now
Egg replacers are useful but it is also easy to make egg free cakes without them – look on the Allergy UK website for recipe information or call the Allergy UK Helpline for further information if you are not able to go online. Baking powder helps a recipe rise; pureed apple, mashed banana and beetroot are just some examples of binding agents that can be used instead of eggs. Chia seeds, flax and chick pea water (aqua faba) are some other very useful egg replacers that will help you add more variety into your egg free diet.
Egg free mayonnaise and other egg free products are now widely availbale in supermarkets, healthfood shops and online.
If you have other food allergies ALWAYS check the labels incase they contain other ingredients you are allergic to.