Peanut Allergy

Symptoms usually occur immediately after eating the food, although can occur up to one hour later. They may include a rash (‘nettle’ rash) or swelling, especially of the face. Some children have an itchy throat, others vomit. Severe reactions (anaphylaxis) are uncommon, but include difficulty breathing (wheeze, or throat swelling), feeling faint or dizzy.

Severe reactions affecting the child’s breathing are uncommon, but are more frequent in those with poorly controlled asthma, and these children need urgent medical attention.

Peanut allergy is more common in children with severe eczema and with egg allergy. Children may be allergic only to peanuts, or also to tree nuts such as cashew and hazelnut, 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 suggested from a history of a typical reaction after contact with peanuts. Positive allergy tests skin prick or blood allergy antibody (IgE) tests support the diagnosis.

In the absence of a previous allergic reaction to peanut allergy tests should not be performed, as they are falsely positive in many patients, leading to an incorrect diagnosis, unnecessary dietary and lifestyle restrictions.

Skin prick tests are safe. The child should not have had any antihistamines for the previous 5 days. Blood tests are not affected by antihistamines, but results are only available a week or so after the clinic appointment. The Ara h2 peanut component blood test is a more precise test of peanut allergy but does not predict how much peanut the child would need to eat before reacting, or if immunotherapy might be an option.

Where there is doubt about the diagnosis, particularly in infants and young preschool children, an oral peanut challenge in hospital should be considered for accurate diagnosis and to prevent unnecessary dietary and life-style restrictions.

Other names for peanuts are ground nuts or monkey nuts. Avoid eating and touching nuts if you are allergic.

Always check the ingredient list on food packets and if in doubt ask the cook who may have changed the recipe. Curries, Indian, Chinese, Thai dishes and Pesto sauce can all contain peanuts.

In the UK and EU, packaging regulations require an accurate ingredient list. 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 when on holidays as foods may be unfamiliar and the ingredients list may not be in English.

Siblings of children with peanut allergy should be encouraged to start eating peanut butter early, as delaying introduction is a risk factor for development of food allergies. They should obviously not share their food with the allergic brother or sister.

A written management plan will be provided, and appropriate medication prescribed which should be always available.

If a peanut is accidentally eaten spit the food out straight away and give an antihistamine as soon as possible.

Severe symptoms:

• 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).

Inform the nursery/school and after school clubs. Grandparents, relatives and school friends’ parents will also need to know.

Most school age children and adults with peanut allergy will not outgrow the problem and need to avoid this food. In contrast, infants and preschool children often tolerate some peanut butter, and are less likely to suffer from anaphylaxis. It is particularly important to make a correct diagnosis in this group. Your allergy team may suggest a peanut oral challenge in hospital, possibly allowing regular reintroduction of peanut into their diet.

There is no permanent cure for peanut allergy. Allergy centres may offer programs to help preschool children tolerate peanuts, but it is unclear if this can cure the problem.

Please telephone, your Children’s Allergy team if you have any queries.