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Overview

It’s not uncommon these days to find schools that have declared they are “nut-free” That means the onetime staple of kids’ lunchboxes — a peanut butter and jelly sandwich — is nowhere to be found on school grounds. That’s because peanuts can cause a life-threatening reaction in some people. Peanuts are one of the food allergens most commonly associated with anaphylaxis, a sudden and potentially deadly condition that requires immediate attention and treatment.

In recent years, awareness about peanut allergy in children has risen, as has the number of peanut allergy cases reported. A 2017 study reported that peanut allergy in children had increased 21 percent since 2010, and that nearly 2.5 percent of U.S. children may have an allergy to peanuts.

There are several misconceptions about peanut allergies. For example, a peanut is a legume (belonging to the same family as soybeans, peas and lentils), not a tree nut. And while it was previously believed that an allergy to peanuts was lifelong, research has shown up to 20 percent of individuals with a peanut allergy eventually outgrow it.

If you suspect a peanut allergy, see an allergist for diagnosis and treatment. Your allergist will work with you to determine the best ways to manage your symptoms.

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Symptoms

The most severe allergic reaction to peanuts is anaphylaxis — a life-threatening whole-body response to an allergen. Symptoms may include impaired breathing, swelling in the throat, a sudden drop in blood pressure, pale skin or blue lips, fainting and dizziness. Anaphylaxis should be treated immediately with epinephrine (adrenaline), typically administered in an auto-injector.

Symptoms of a peanut allergy may include:

  • Vomiting
  • Stomach cramps
  • Indigestion
  • Diarrhea
  • Wheezing
  • Shortness of breath, difficulty breathing
  • Repetitive cough
  • Tightness in throat, hoarse voice
  • Weak pulse
  • Pale or blue coloring of the skin
  • Hives
  • Swelling, can affect the tongue and/or lips
  • Dizziness
  • Confusion

Diagnosis

Diagnosing a peanut allergy can be complicated. Symptoms can vary from person to person, and a single individual may not always experience the same symptoms during every reaction.

If you suspect you are allergic to peanuts, make an appointment to see an allergist. Start a food diary before the appointment and keep track of any reactions. If you have a reaction, you should note:

  • What (and how much) you ate
  • When the symptoms started (after eating the suspected food)
  • What you did to relieve the symptoms
  • How long it took before the symptoms were relieved

Your allergist may recommend a skin test or blood test to help diagnose whether you have a peanut allergy or allergy to another substance. The allergist may also recommend an oral food challenge. During this test, you will be fed tiny amounts of peanut or peanut-based products in increasing doses over time in an allergist’s office or a food challenge center. Emergency medication and emergency equipment will be on hand during this procedure in case you have a severe reaction.

Management and Treatment

Peanut is one of eight allergens with specific labeling requirements under the Food Allergen Labeling and Consumer Protection Act of 2004. Under that law, manufacturers of packaged food products that contain peanut as an ingredient that are sold in the U.S. must include the word “peanuts” in clear language on the ingredient label.

To avoid the risk of anaphylactic shock, people with a peanut allergy should be very careful about what they eat. Peanuts and peanut products may be found in candies, cereals and baked goods such as cookies, cakes and pies. If you’re eating out, ask the restaurant staff about ingredients - for example, peanut butter may be an ingredient in a sauce or marinade. Be extra careful when eating Asian and Mexican food and other cuisines in which peanuts are commonly used. Even ice cream parlors may be a source for accidental exposures, since peanuts are a common topping.

Foods that don’t contain peanuts as an ingredient can be contaminated by peanuts in the manufacturing process or during food preparation. As a result, people with a peanut allergy should avoid products that bear cautionary statements on the label, such as “may contain peanuts” or “made in a factory that uses nut ingredients.” Note that the use of those advisory labels is voluntary. It may be a good idea to discuss with your allergist the risks of consuming products with voluntary labeling.

If you’re cooking from scratch, it’s easy to modify recipes to remove peanut ingredients and substitute ingredients that aren’t allergens, such as toasted oats, raisins or seeds. Most people who can’t tolerate peanuts or eat peanut butter can consume other nut or seed butters. Keep in mind that these products may be manufactured in a facility that also processes peanuts - so check the label carefully and contact the manufacturer with any questions.

Many individuals with an allergy to peanuts can safely consume foods made with highly refined peanut oil, which has been purified, refined, bleached and deodorized to remove the peanut protein from the oil. Unrefined peanut oil - often characterized as extruded, cold-pressed, aromatic, gourmet, expelled or expeller-pressed - still contains peanut protein and should be avoided. Some products may use the phrase “arachis oil” on their ingredient lists; that’s another term for peanut oil. If you have a peanut allergy, ask your allergist whether you should avoid all types of peanut oil.

While some people report symptoms such as skin rashes or chest tightness when they are near to or smell peanut butter, a placebo-controlled trial of children exposed to open peanut butter containers documented no systemic reactions. Still, food particles containing peanut proteins can become airborne during the grinding or pulverization of peanuts, and inhaling peanut protein in this type of situation could cause an allergic reaction. In addition, odors may cause conditioned physical responses, such as anxiety, a skin rash or a change in blood pressure.

Can peanut allergy be prevented?

In 2017, the National Institute for Allergy and Infectious Disease (NIAID) issued new updated guidelines in order to define high, moderate and low-risk infants for developing peanut allergy. The guidelines also address how to proceed with introduction of peanut based on risk in order to prevent the development of peanut allergy.

The updated guidelines are a breakthrough for the prevention of peanut allergy. Peanut allergy has become much more common in recent years, and there is now a roadmap to prevent many new cases.

According to the new guidelines, an infant at high risk of developing peanut allergy is one with severe eczema and/or egg allergy. The guidelines recommend introduction of peanut-containing foods as early as 4-6 months for high-risk infants who have already started solid foods, after determining that it is safe to do so.

If your child is determined to be high risk, the guidelines recommend having them tested for peanut allergy. Your allergist may do this with a skin test or blood test. Depending on the results, they may recommend attempting to try peanut for the first time in the office. A positive test alone does not necessarily prove your child is allergic, and studies have shown infants who have a peanut sensitivity aren’t necessarily allergic.

For high-risk infants, if the skin test does not reveal a large wheal (bump) updated guidelines recommend that infants have peanut fed to them the first time in the specialist’s office. However, if the skin test reaction is large (8 mm or larger) the guidelines recommend not pursuing an oral challenge, as the infant is likely already allergic at that point. Therefore, an allergist may decide not to have the child try peanut at all if they have a very large reaction to the skin test. Instead, they might advise that the child avoid peanuts completely due to the strong chance of a pre-existing peanut allergy. An allergist might also still proceed with a peanut challenge after explaining the risks and benefits to the parents.

Moderate risk children – those with mild to moderate eczema who have already started solid foods – do not need an evaluation. These infants can have peanut-containing foods introduced at home by their parents starting around six months of age. Parents can always consult with their primary health care provider if they have questions on how to proceed. Low risk children with no eczema or egg allergy can be introduced to peanut-containing foods according to the family’s preference, also around 6 months.

Parents should know that most infants are either moderate- or low-risk for developing peanut allergies, and most can have peanut-containing foods introduced at home. Whole peanuts should never be given to infants as they are a choking hazard. More information can be found here and also in the ACAAI video, “Introducing peanut-containing foods to prevent peanut allergy.”

Although parents want to do what’s best for their children, determining what “best” means isn’t always easy. So if your son or daughter is struggling with peanut allergies, take control of the situation and consult an allergist today.

 

This page was reviewed and updated 3/14/2019.