Peanut Allergies

In January 2019, the Canadian Paediatric Society (CPS) released updated recommendations on the specific timing of early introduction of allergenic foods for high-risk infants. The following guidance for practice is based on evidence supporting the early introduction of common allergenic foods to high risk infants:

• Infants considered to be at high risk for allergenic disease have either a personal history of atopy (e.g. eczema) or a first-degree relative with atopy such as a parent or sibling.
• For high-risk infants, and based on their developmental readiness for food, consider introducing peanut at around 6 months of age, but not before an infant is 4 months of age.
• For infants at no or low risk for food allergy, introducing complementary foods at about 6 months is recommended.
• Breastfeeding should be promoted for up to 2 years and beyond.
• Allergenic foods should be introduced one at a time to gauge reaction, without unnecessary delay between each new food.
• If an infant appears to be tolerating peanut, advise parents to offer if a few times a week to maintain tolerance. If an adverse reaction is observed, advise parents to consult with a primary care provider about next steps.
• The texture or size of any complementary food should be age-appropriate to prevent choking.

The most striking evidence for early introduction of peanut was the Learning Early About Peanut (LEAP) prospective allergy study in the U.K. – the first randomized controlled trial to show that early peanut introduction could help prevent peanut allergy in high risk infants. In the study, 640 high-risk infants between the ages of 4 to 11 months were randomly assigned to either consume peanut protein at least 3 times per week, or avoid peanuts until they were 5 years old. Findings showed an overall relative risk reduction in peanut allergy of up to 80% with early peanut introduction. (Source: Du Toit, G., et al. Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy. N Engl J Med 2015; 372:803-813.)

Canadian allergists suggest a few options for feeding peanut-containing foods to young infants. The simplest method is to combine 2 tsp (10 mL) of smooth peanut butter with 2-3 tsp (10-15 mL) of hot water, then allow to cool. This mixture can be offered alone, or added to 2-3 tbsp (30-45 mL) of infant cereal, pureed fruit or vegetables, or other soft food such as tofu or yogurt. This will provide 2 g of peanut protein in each serving. Once prepared, a small amount of this mixture can be offered to the infant on the tip of a spoon. After 10 minutes, if no symptoms develop, the remainder of the peanut-containing food can be given, at the infant’s usual pace of eating.

It is not recommended to place the food on the skin first, as the food may cause irritation that could be misinterpreted as an allergic reaction. Skin contact with a food is not a way to determine if it will be tolerated when it is eaten. Whole peanuts are a choking hazard and should not be offered to children under four years of age. (Source)

Once peanut protein is introduced into the diet and tolerated, it should be consumed on a regular basis in order to maintain a tolerance. The total amount consumed per week should be a total of 6-7 g of peanut protein over three or more feedings, which would satisfy the recommendation made by the National Institute of Allergy and Infectious Diseases (NIAID) guidelines for early peanut introduction. Lesser amounts may be adequate, as long as there is regular exposure (e.g. several times a week). (Source)

Current research suggests that in high-risk infants (those with egg allergy and/or severe eczema) the addition of peanut foods into the diet early on can drastically reduce that child’s chance of having peanut allergy. (Source)

Current guidance suggest that younger siblings of peanut allergic children can be treated like any other child. However, given that their situation is slightly different, it is recommended that parents discuss early introduction of peanut, in this case with their pediatrician or allergist.  Many parents who have an older child with a peanut allergy may be fearful when it comes to introducing peanut into a younger infant’s diet. In this case, it may be reasonable to have the younger child tested first, even if they are low risk. (Source)

• The Canadian Paediatric Society
• Food Allergy Canada
• The National Peanut Board
• Prevent Peanut Allergies

A food allergy is any reaction to an otherwise harmless food or food component that involves the body’s immune system. A reaction occurs when the body’s immune system responds abnormally to the protein or proteins in that particular food. The body reacts by flooding the system with histamines and other chemicals to fight off what is perceived as an invader in the body.

Yes. Although anyone can develop a food allergy at any time, the tendency toward allergic reactions is largely inherited. Where there is a history of atopic disorders (such as asthma or eczema) or other allergies, children may have two to four times the likelihood of developing an allergy as compared to children from families without allergic parents.

Most allergy sufferers experience mild reactions. Symptoms can include varying degrees of hives, swelling of the throat, difficulty breathing and vomiting. A small proportion of susceptible sufferers may experience severe and potentially fatal anaphylactic shock.

Anaphylaxis is a rare but potentially fatal condition in which several different parts of the body experience severe allergic reactions simultaneously. This may include swelling of the mouth and throat, a drop in blood pressure, unconsciousness, hives and other symptoms. Anaphylactic reactions can be mild to life-threatening and can occur within minutes to four hours after exposure to the allergen, requiring immediate medical care. Emergency treatment often includes injection of epinephrine. Persons with food allergies often are prescribed epinephrine to carry with them at all times in the event of anaphylaxis.

Yes. Though most individuals develop food allergies in early childhood, food allergies can develop at any age.

Children commonly outgrow food allergies. However, allergies to peanuts, nuts, fish and shellfish are usually life-long.

Peanut is a part of the legume family and not tree nut; however, while peanuts and tree nuts are different, in some cases people with a tree nut allergy also react to peanuts. Consult your allergist before eating peanuts or any tree nuts that are not a regular part of your diet. (Source)

Peanuts are a complex plant food, with more than 30 different proteins. Research is underway to identify exactly which proteins trigger an allergic reaction, and why the reaction can vary in severity among allergy sufferers. Peanut allergy appears to be progressive – subsequent reactions tend to be more severe. Health Canada has identified ten primary food allergens: eggs, milk, soy, tree nuts, peanuts, seafood (fish, crustaceans and shellfish), sesame, sulphites, mustard and wheat.

No, simply smelling the aroma of peanuts is not the same as breathing in protein particles which would cause an allergic reaction. The chemicals which are detected as the odour of peanuts are aromatic molecules called pyrazines and are incapable of causing allergic reactions.

Research indicates that all food allergies are increasing. Some hypothesize that the lack of early childhood exposure to potential allergens, such as infectious agents and parasites, has increased susceptibility to allergic diseases. It’s difficult to determine if the increased reports of food allergies in general and peanut allergy in particular are due to actual increases in incidence or a result of increased awareness among consumers and health professionals.

Recent evidence indicates that even trace amounts of peanuts can be enough to cause a major reaction in those very few individuals who are severely allergic.

Diagnosing a food allergy may not be difficult if a person always has the same reaction after eating a certain food. However, foods are generally eaten in combination. It is therefore important to consult a certified allergist to determine if the symptoms are caused by food and if so, which one.

Food allergies are diagnosed by taking a thorough medical and dietary history, keeping a food diary, eliminating suspect foods, conducting skin tests, and evaluating food challenges. It is important to consult a board-certified allergist if you suspect you have a food allergy. Allergists can accurately diagnose the allergy and prescribe medication for its treatment.

The only certain way to prevent a reaction is avoidance – there is no treatment to prevent peanut allergy. However, with proper management, awareness and education, most reactions to food allergens can be avoided.

Individuals with a food allergy should diligently read all food labels and ask questions about foods prepared away from the home (such as at school or a restaurant). In the day care or school setting, parents of a child with a food allergy should inform teachers and school staff, so they are prepared to recognize and treat severe allergic reactions immediately and seek first aid.

In consultation with their physicians, individuals who experience severe allergic reactions should always carry appropriate medication such as a self-injectable form of epinephrine (adrenaline) and should also consider wearing an identity bracelet or medallion to alert others if they have a problem.

Epinephrine, when prescribed by a physician, should be administered immediately to the individual suffering from a severe reaction to food. Emergency medical services must then be obtained for further treatment.

It is important to note that an injection of epinephrine does not cure the allergic reaction – it only alleviates the immediate reaction to allow the extra time necessary to seek emergency medical services.

In June 2016, the Canadian Transportation Agency (CTA) released a report on the Ministerial Inquiry into Allergies to Peanuts, Nuts and Sesame Seeds in Commercial Air Travel. The report concludes that "there is little or no evidence that there is a risk of anaphylaxis due to inhalation of or dermal contact with peanut, nut or sesame seed allergens while on board aircraft." The report also makes recommendations for effective risk mitigation, which includes a row of buffer zone in which the allergic passenger is seated. For the full report, visit the Canadian Transportation Agency website.

The process of refining oil removes the protein which would trigger an allergic reaction. Peanut oil (sometimes labelled as arachis oil) is commonly used as a component in vegetable oil, as a carrier in processed foods or as an emulsifier/lubricant in cosmetics. The oil is highly refined, and should pose no problem for those with allergies. However, oils which are cold pressed to retain their flavour or oil that has been used to cook peanuts do contain protein and therefore should be avoided.

No. A food allergy is an immune system response to a protein in a food. The protein remains in the food during heating, therefore, you cannot make a food less allergenic by cooking it.

Yes. It is possible that peanuts could be found in the following:

• Sauces such as chili sauce, hot sauce, pesto, gravy, mole sauce and salad dressing
• Sweets such as pudding, cookies, and hot chocolate
• Egg rolls
• Potato pancakes
• Pet food
• Specialty pizzas
• Asian and Mexican dishes
• Some vegetarian food products, especially those advertised as meat substitutes
• Foods that contain extruded, cold-pressed, or expelled peanut oil, which may contain peanut protein
• Glazes and marinades

To learn more about food allergies, check out Food Allergy Canada's online resources and learning tools, available on allergyaware.ca. This is a free, medically-reviewed resource designed for people with potentially life-threatening allergies and those who care for them. 

For more information about food allergies, you can also visit the websites below:

• Food Allergy Canada
• Allergies Québec
• The National Peanut Board
• Prevent Peanut Allergies
• Canadian Allergy Asthma and Immunology Foundation
• Canadian Society of Allergy and Clinical Immunology
• Health Canada