It is an allergy to peanut protein (not oil) that causes the reaction after eating or touching the nut. Peanut allergy is common, affecting 1/80 people, or about a million people in the UK.
Symptoms usually occur straight after eating food containing peanuts but can occur up to a few hours later. They tend to be mild and may include a rash (hives or “nettle” rash) or swelling, especially around the face. Some children have an itchy throat; others vomit or have diarrhoea. Severe reactions (anaphylaxis) are much less common, but include difficulty breathing (with wheeze or swelling in the throat), feeling faint or dizzy.
Most people with peanut allergy only have mild reactions. Severe reactions affecting the child’s breathing can occur, particularly in those with asthma which is not well controlled and these need urgent medical attention. More severe reactions may also occur if the child has a cold, following intense exercise, at times of stress or in teenagers after drinking alcohol.
Children can be allergic to peanuts alone or may also be allergic to other nuts such as cashew and brazil; seeds such as sesame; and legumes such as lentils and peas. Seek medical advice before excluding any of these other foods as this may not be necessary.
The diagnosis is based on a history of a typical reaction after contact with peanuts. Positive allergy tests skin prick or blood allergy antibody (IgE) tests support the diagnosis, but should not be used alone, as people can have positive allergy tests but tolerate the food without getting a reaction. Skin prick tests are safe. They can be done in clinic provided that the child has not had any antihistamines for a few days.
Blood tests are not affected by antihistamines, but the results are only available a week or so after the clinic appointment.
An oral peanut challenge in hospital is sometimes recommended to confirm the diagnosis and determine how allergic you are to the peanut.
Avoiding eating and even touching nuts is important in someone with a peanut allergy. Other names for peanuts are ground nuts, monkey nuts, goober nuts or mixed nuts. Always check the ingredient list on food packets.
When eating out, check the ingredients and if in doubt ask the cook who may have changed the recipe. Curries, Indian, Chinese and Thai dishes and Pesto sauce can all contain peanuts. The spices in some of these foods may hide the warning signs of an allergic reaction. This makes them particularly risky as a significant quantity of peanut may have been eaten before the problem is recognised. Your doctor should advise you whether it is safe to eat other nuts.
Be more careful when on holiday abroad as foods may be unfamiliar and the ingredients list may not be in English.
In the UK and EU, packaging regulations require an accurate ingredient list. Thus, if peanuts are not listed in the ingredients section, foods where packaging just states “may contain traces of nuts” can be safely eaten. Outside the EU, regulations are different – be careful.
A written management plan will be provided and appropriate medication prescribed which should be available at all times.
If a peanut is accidentally eaten spit the food out straight away and give an antihistamine as soon as possible.
- Difficulty breathing (wheezing, noisy breathing)
- Swelling in the throat (noisy breathing, drooling)
- Feeling faint or dizzy, looking very pale (lie the child down with their legs raised).
If any of these severe symptoms occur get help straight away and dial 999 stating “anaphylaxis” (ana-fil-ak-sis).
It is important to inform the nursery/school and any after school clubs. Any other carers such as grandparents, relatives and school friends’ parents will also need to know.
Most children with peanut allergy will not outgrow the problem. If there has been no reaction for a long time and allergy tests to peanut are negative an oral challenge may be suggested.
There is no cure for peanut allergy at present. Some allergy centres offer programs to help children tolerate peanuts, but it is unclear if this can cure the problem.