This is one of the most serious food allergies because more than most other it carries a risk of life-threatening anaphylaxis. Worryingly, cases seem to be on the increase throughout the world, particularly in the more developed countries, where it is the most common reason for food allergy deaths. Symptoms are caused because the immune system of those affected overreacts to the protein found in peanuts.
The peanut, or ground-nut as it is sometimes known, is not a tree-nut; rather it is a legume from the same family as peas, soy and lentils. It used to be thought that a person diagnosed with peanut allergy would have the condition for life, although more recent studies have shown that some people outgrow it. However there is still a risk that the allergy may return in those who are thought to have outgrown it.
It is not known what causes an individual to develop peanut allergy. Persons with a family history of allergies, or who themselves have other allergies are more at risk. Some studies have suggested that exposure to peanuts in the womb or between the ages of 4 to 11 months can reduce the risk of developing the condition. Follow advice from your health provider before exposing a baby to peanuts. The allergy is less common in children who have older siblings, although more common in children who have siblings with peanut allergy.
Symptoms of Peanut Allergy
Symptoms can appear within minutes. They can be mild, particularly where peanuts have been touched but not eaten. The following symptoms might be present:
- Itchiness, hives or atopic eczema
- Itching, tingling or swelling around the mouth and throat
- A blocked or runny nose, sneezing
- Diarrhea, abdomen pain, nausea or vomiting
- Life-threatening anaphylaxis.
Anaphylaxis and Peanut Allergy
Anaphylaxis is a severe, often sudden reaction where the body goes into shock, sometimes as a reaction to peanuts. It can cause death and should always be treated as a medical emergency. If anaphylaxis is suspected call an ambulance immediately.
Symptoms may include general distress, difficulty breathing, tightness or a lump in the throat, a fast pulse, a drop in blood pressure, fainting and loss of consciousness. Victims sometimes describe feeling a strong sense of doom.
A person who has had only a mild reaction to peanuts in the past is still at risk of anaphylaxis in the future.
Those who have been diagnosed as at risk of anaphylaxis will have been prescribed equipment for self-administration of Epinephrine (known as Adrenaline in the UK and Australia) which may be found under the brand-names EpiPen/ Auvi-Q/ Twinject, for immediate self-administration once the first symptoms appear. Follow medical advice on how and when to use it. Always carry your auto-injector with you and never eat unless you have it with you. If a child has been prescribed an auto-injector make sure that her teachers and other carers know how to use it. Regularly check the expiry date on your auto-injector and ensure that you have at least two doses of epinephrine with you at all times.
Your doctor is likely to ask about the circumstances in which you experienced symptoms, particularly your level of exposure to peanuts and how quickly your symptoms developed. It may be a good idea to keep a food diary for the days or weeks before your appointment, keeping a record of any symptoms. You will probably be asked about your general health and whether or not there is a family history of allergies.
You may be offered a skin-prick test, during which a small amount of peanut protein is placed on your skin which is then pricked with a needle. If you have a peanut allergy a red bump may appear. However this test is probably only about 50% accurate. A blood test may be done to test your immune system’s response to the proteins found in peanuts. You may be asked to eliminate certain foods from your diet. As a last resort your allergist may conduct a food-challenge test, where you are given small amounts of peanut to eat to observe the reaction. The food challenge test is not without risk and should only be done in conditions where you are being closely monitored by a medical practitioner, with emergency medication at hand.
Management of Peanut Allergy
If you suffer from a peanut allergy then the only way to be sure of avoiding a reaction is by avoiding peanuts and peanut products altogether. Do not eat peanuts, peanut butter, beer nuts, mixed nuts, ground nuts, earth nuts, goobers, goober nuts or monkey nuts. Peanuts might also be found in cakes, cookies, chocolate bars, ice creams, cereal bars, energy bars, nougat, sauces, marinades, salad dressings and vegetarian foods. Chili and pesto are sometimes thickened using ground peanuts. It is always important to check food labels to see if what you are about to eat may contain traces of peanuts or is made in a factory where peanuts are processed. Even the smallest amount of peanut protein can cause a reaction and potentially anaphylaxis. Some, but not all people with peanut allergy find that they can tolerate highly refined peanut oil. However unrefined/crude peanut oil is not safe. This may sometimes be labelled as cold-pressed, expelled or extruded peanut oil. Peanut oil may also be called arachide, arachic oil, arachis, aceite de cacahete, aceite de mani and cacahouè, te. Never assume that any type of peanut oil is safe without discussing it with your allergist.
Some non-food items such as candles can contain peanuts, as can bird- food and pet- food.
If you are eating out you should let your host or the restaurant know in advance about your allergy and the potentially life-threatening nature of a reaction. Do not be afraid to ask detailed questions about ingredients and about where food is prepared. Asian, Mexican and African restaurants often use peanuts in their ingredients so these are probably best avoided. Ice-cream parlors are also best avoided as there is a risk of the same scoop being used for ice-creams containing peanuts and other ice-creams.
While peanuts are a legume, a peanut allergy does not necessarily mean that other legumes such as peas and soy products need to be avoided. Seek medical advice about what is safe for you to eat. The legume lupin / lupine beans, which are sometimes used in traditional Mediterranean and Latin American cuisine, should be avoided by those with peanut allergy.
Peanuts are not a type of tree-nut and the proteins found in peanuts differ from those found in tree-nuts, so some people who are allergic to peanuts can eat other types of nuts. However some people are allergic to both types of nuts so speak to your allergist about which type of nuts may be safe for you. Sunflower seeds are often processed in the same factories as peanuts, so these too can pose a risk to some highly sensitive persons.
It is a good idea for those with a peanut allergy to wear a medical identification tag, such as a necklace or bracelet.
It is vital to teach children with peanut allergy not to share any food or snacks with other children.