Peanut and Tree Nuts (almonds, hazelnut, walnut, cashew, pistachio, pecan, brazil, macadamia/queensland)
Allergy to peanut and tree nuts is the most common food allergy in adults and children. However, since most children start eating other foods first, allergies to other foods such as egg and cows' milk protein typically appear before nut allergies.
While children often grow out of other allergies, only around 20% of children with nut allergies resolve, meaning that 4 out of 5 children with nut allergies will continue to have these allergies as an adult. In some people, the allergy may become less severe with age, but in 20%, it can become worse with time.
The majority of allergic reactions to peanut and tree nuts are mild. Hives (nettle rash), eczema and vomiting are the most common complaints in children, however, some allergic reactions to peanut or tree nuts can be severe, causing difficulty in breathing due to asthma or throat swelling, or a drop in blood pressure. This is known as anaphylaxis, and allergy to peanut or tree nuts is one of the most common triggers.
In any case where an allergic reaction to a nut is suspected, the patient should be referred by their General Practitioner to an NHS allergy clinic for testing to confirm the diagnosis, which can be done by Skin Prick Tests or blood tests.
What are peanuts?
Peanuts (Arachis hypogaea) are a member of the legume (bean) family and grow from the ground rather than on trees, and are sometimes referred to as ground nuts. It’s rare for a peanut-allergic person to react to soya or other beans and legumes, but many peanut allergic people will also be allergic to other tree nuts, for example brazil or hazel nuts, which are genetically unrelated.
Many commonly used foods contain peanut extracts, but although hydrogenated vegetable oil may occasionally have a peanut source, it is unlikely to cause an allergic reaction. Hydrogenated vegetable protein might in rare cases have a peanut source, and this may cause an allergic reaction in an extremely sensitive individual.
What are tree nuts?
Tree nuts are actually a type of seed which come from plants from a wide variety of different botanical families such as Rosaceae (almonds), Anacardiaceae (cashews), Proteaceae (macadamia nuts) or Lecythidaceae (Brazil nuts).
The distinction between tree nut and seed is not always clear. We often think of seeds as small seeds - like sesame seeds or pumpkin seeds. In fact, coconut (including the husk and inner white flesh that we eat) is also a seed, albeit a very large one. This might explain why coconut is considered to be a tree nut in USA but a seed elsewhere.
There are 3 stages to managing a food allergy:
1. Identify and avoid the cause (if possible)
2. Recognize the symptoms of an allergic reaction
3. Know what to do if it happens again
For this reason, anyone identified as having (or suspected of having) a food allergy should be referred to an allergy specialist.
Many people with an allergy to peanut or tree nut will be prescribed an Adrenaline Auto-Injector Device. This is because nut allergy is the most common food to cause severe anaphylactic reactions (although most reactions to nuts aren’t severe). Doctors usually prescribe the adrenaline pens for nut allergies because there is no test which can predict who is at risk of anaphylaxis. Since giving adrenaline for those with food allergies is very safe and effective, they’re used as a crucial step in management.
Avoiding peanut and tree nuts
Reactions to peanuts or nuts can be life threatening. Once a person is diagnosed it’s important that nuts and all sources of nuts are excluded from their diet at all times, unless an Allergy Specialist has told them otherwise.
Manufacturers are definitely improving their labels, but those with allergies still have to find out a lot about the content of foods themselves. Some foods obviously contain nuts while in others, nuts may be a hidden ingredient. If you have an allergy, your doctor may occasionally tell you to avoid foods such as peas, beans, lentils and other legumes, while high-risk foods should only be introduced with the supervision of a Doctor or Dietician. Those with such allergies should never reintroduce peanuts into the diet without medical supervision.
Peanuts are a very popular food and often included in confectionery, biscuits and Oriental food and, as such, it may not be possible to avoid them even with the most strenuous efforts. Contaminations through the use of some production lines or the same utensils can occur. The food industry takes these issues seriously and many voluntarily label food as “contains peanuts” or “may contain trace of peanuts”.
In restaurants and take-aways, inclusion of peanuts is a potential hazard particularly where peanuts are a staple, but peanut butter has been found to be the “secret ingredient” in some dishes. No one can guarantee complete avoidance of any food allergen and all food which you don’t prepare yourself must be considered somewhat suspect. However, with the right medication (Adrenaline or antihistamines), the risk is minimal provided you use it immediately and then go straight to hospital.
All of the major supermarket chains in this country provide “Free From” lists, and it’s possible to get a list of own brand foods which don’t contain peanuts. However, companies do change the ingredients in their processed foods, sometimes without stating that they have. It’s always best to read the list of ingredients on processed foods, even if you have eaten it without problems before.
If in doubt of the contents of any product, contact the manufacturer before trying it.
Foods to avoid
• Blended Oils, Unrefined / Gourmet Peanut, and Groundnut oils.
• All Biscuits, Almonds, Coconut biscuits, Macaroons, or Nut Oils.
• Peanut Butter, Chestnut Puree, Chocolate and Hazel Spread, Praline Spread, Sweet Mincemeat.
• Christmas cake, Fruit Cake, Stollen, Marzipan containing cakes, Carrot Cake, Passion Cake, Cakes bought in Delicatessen, Cakes containing vegetable oil.
• Crunchy Nut Cornflakes, Fruit & Fibre, Muesli, Shreddies, Fruitful, etc.,
Dips & Sauces
• Pesto Sauce, Waldorf salad.
• Nut Loaf, Vegeburgers, Sausages. (Some products may be OK - Check Labels).
• Nut Yoghurt, Nut Ice-creams, Cakes, Puddings containing nuts.
• Nuts, Nougat, Nut Brittle, Halva, Snickers, Topic, Fruit & Nut, Bounty, Toblerone, Liquorice Allsorts, Pralines, Florentines.
Some Chinese Foods e.g. Satay.
It is also advisable to avoid Creams and Shampoos containing nut extracts.
Always check the labels on all food purchased.