Peanuts are one of the most dangerous allergies because peanuts tend to cause particularly severe reactions. Peanut allergies account for the largest number of allergy-related deaths and the greatest incidence of anaphylaxis (a serious allergic reaction that can cause death). For some individuals, trace amounts of peanuts can cause a severe reaction. Non-ingestion contact (such as touching peanuts or inhaling peanut particles) is less likely to trigger severe reactions compared with ingestion contact. Even so, extreme caution should always be used because proximity to peanuts increases the opportunity for ingestion. The prevalence of peanut allergies in American children tripled from 1997 to 2008. Still, approximately 20% of children with a peanut allergy do outgrow it.

The most common symptoms of an allergic reaction to peanuts include:

• Eczema
• Hives, redness, or swelling of the skin
• Itching or tingling around or in mouth and throat
• Tightness in throat
• Asthma, shortness of breath, or wheezing
• Runny nose
• Digestive symptoms (diarrhea, stomach cramps, nausea, or vomiting)

Peanut is the most common cause of food-induced anaphylaxis. Signs of anaphylaxis may include one or more of the following symptoms:

• Constriction of airways (swollen throat or a lump in the throat making breathing difficult)
• A severe drop in blood pressure
• Rapid pulse
• Shock (a severe drop in blood pressure felt as dizziness, lightheadedness, or loss of consciousness)

There are many unexpected sources of peanuts, so reading food labels is important to eliminate exposure to peanuts. Peanuts are often ingredients in prepared products and ethnic cuisines, such as African, Chinese, Indonesian, Mexican, Thai, and Vietnamese foods. Artificial nuts can be peanuts that have been deflavored and reflavored with pecan, walnut, or almond. Mandelonas are peanuts soaked in almond flavoring.

Many items may not contain peanuts but may be produced in a facility where peanuts are processed or used as an ingredient. As a result, cross-contact with peanuts may occur. Many snack foods may be produced in a facility where many different types of snack foods or many different varieties of a product (for example, cereal bars) are produced. Some of the varieties of that product may include peanuts or peanut butter. A product that is labeled as being produced in a facility with peanuts should not be consumed by an individual with a peanut allergy.

Products or Ingredients with Peanuts

• Arachis oil (another name for peanut oil)
• Artificial nuts
• Beer nuts
• Candy/Candy cereals (chocolate candy)
• Chili
• Cold-pressed, expressed, or expelled peanut oil*
• Egg rolls
• Enchilada sauce
• Frozen yogurt and ice cream
• Glazes and marinades
• Granola bars, cereal bars, and breakfast bars
• Ground nuts
• Hydrolyzed plant protein
• Hydrolyzed vegetable protein
• Ice creams
• Lupin (or lupine) – common flour substitute for gluten-free food, reaction due to possible cross-reaction
• Mandelonas (peanuts soaked in almond flavoring)
• Marzipan
• Mixed nuts
• Nougat
• Nut meat
• Nut pieces
• Peanuts, peanut butter, peanut flour, monkey nuts, and goobers
• Peanut protein hydrolysate
• Potato pancakes
• Sauces such as chili sauce, spaghetti sauce, hot sauce, pesto, gravy, mole sauce, and salad dressing
• Specialty pizzas
• Sweets such as pudding, cookies, and hot chocolate
• Vegetarian food products, especially those advertised as meat substitutes

* Highly refined peanut oil is not required to be labeled as an allergen.

Those with peanut allergies need to be mindful of food items that may be produced on equipment that also produces peanuts. These food items could still cause a reaction for a child with a peanut allergy. Some examples include:

• African, Asian, and Mexican restaurant food
• Alternative nut butters, such as soy nut butter or sunflower seed butter
• Sunflower seeds

Peanut allergy is one of the most common food allergies and can trigger a life-threatening reaction in some. The allergy usually starts in early childhood and lasts a lifetime. There is presently no cure. Most people remain allergic their entire lives.

Researchers have been exploring oral immunotherapy to treat peanut allergy. This involves giving people increasing doses of peanut flour over time in order to desensitize them to peanut. Providing such oral immunotherapy early in life, when the immune system is still maturing, might more effectively modify a child’s immune response to peanut than waiting until later. Two earlier studies provided evidence that peanut oral immunotherapy could be given safely to very young children and have a therapeutic effect.

A new clinical trial further assessed whether oral immunotherapy could treat peanut allergy in very young children. The study, which was led by Drs. Wesley Burks of the University of North Carolina at Chapel Hill and Stacie Jones of Arkansas Children’s Hospital, was funded by NIH’s National Institute of Allergy and Infectious Diseases (NIAID). Results appeared in the Lancet on January 22, 2022.

The trial included 146 children ages 1 through 3 at five U.S. medical centers. All the children experienced an allergic reaction after eating 0.5 grams or less of peanut protein at the start of the trial. They were randomly assigned to receive either flour containing peanut protein or a placebo oat flour that looked similar. The flours were mixed with foods such as applesauce or pudding to mask their taste.

Over 30 weeks, the children in the treatment group ate gradually increasing daily doses of peanut protein. Their maximum dose was 2 grams of peanut protein, equivalent to about six to eight peanuts. The children then continued their daily doses for an additional two years.

Next, they underwent an oral food challenge. They received gradually increasing doses of peanut protein, to a total of 5 grams. The researchers found that 71% of children who had received peanut flour were desensitized to peanut, compared to only 2% of those who had received the placebo flour. Desensitization was defined as being able to eat 5 grams of peanut protein without an allergic reaction.

The children then stopped treatment and avoided peanut for six months. At the end of this period, the children underwent another oral food challenge to a total of 5 grams of peanut protein. Those who did not have an allergic reaction were later fed 8 grams of peanut butter, equivalent to 2 tablespoons, to confirm that they could eat peanut without having an allergic reaction.

The team found that 21% of children who had received peanut flour could eat peanut six months after treatment without having an allergic reaction. These children were considered to be in remission. Only 2% of children who had received placebo flour were in remission.

The study also found that the youngest children and those who started the trial with lower levels of peanut-specific antibodies were most likely to achieve remission. 

“The landmark results of the trial suggest a window of opportunity in early childhood to induce remission of peanut allergy through oral immunotherapy,” says NIAID Director Dr. Anthony Fauci. “It is our hope that these study findings will inform the development of treatment modalities that reduce the burden of peanut allergy in children.”

If you have a peanut allergy, you should follow the same general safety suggestions as people with all food allergies. Here are some additional tips for you:

• People with peanut allergies often also are allergic to tree nuts, such as almonds, walnuts, cashews, and pecans. Allergies to sesame seeds or sesame oils are pretty rare, but people with peanut allergies may have those, too.
• Nuts might be in some products that you might think would not have them. These include cereals, crackers, chocolates, energy bars, flavored coffees, frozen desserts, sauces, and even some artificial nuts.
• If you can't eat peanuts, you most likely should not eat food that is made in a factory that has any nut products in it. Read labels for phrases like "produced in a facility that also processes nuts" and "produced on shared equipment with nuts or peanuts."
• Some schools now have peanut-free zones. Ask your doctor about whether you should be sitting in one.
• Be extra careful in certain kinds of restaurants. Some restaurants have a lot of nut products that can accidentally wind up touching your food. These include Chinese, Indian, and Thai restaurants, ice cream parlors, and bakeries.
• Airplane travel can pose problems. Talk with your doctor and with the airline to discuss ways to protect your health. Some airlines will try to give you a peanut-free zone if you contact them in advance. And make sure to have an EpiPen with you on board.

Some types of food allergies may go away on their own, but there is no cure yet for food allergies. If you have a food allergy, you should not eat that food. Here are some suggestions to help keep you safe:

• Read food labels. Packages will have a special note, usually near the ingredients list. You can also check the ingredients list for anything you should avoid. Your doctor's office or a food allergy organization can give you a list of ingredients to avoid. And don't forget to check a product every time you buy it. Sometimes the food maker may change its ingredients.
• Find out if the factory matters. If you are very sensitive, you may need to avoid a food just because it is made in the same factory as your allergic food. Ask your doctor about that.
• Tell people who might need to know. Teachers, coaches, friends, and restaurant servers can help you stay safe if they know what foods you need to avoid.
• Be prepared. Learn what to do in case you have a reaction.Some people with a food allergy need to have medicine nearby all the time. You may need an EpiPen to protect you in case you have a life-threatening reaction called anaphylaxis (say: an-uh-fuh-LAK-suhss). You might also consider wearing a medical identification bracelet, so other people know how to help you in an emergency.

Food labels can help consumers with food allergies avoid foods or ingredients that they or their families are allergic to.

This is because a federal law, the Federal Food, Drug and Cosmetic Act, requires that the labels of most packaged foods marketed in the U.S. disclose — in simple-to-understand terms — when they are made with a “major food allergen.”

Nine foods, and ingredients containing their proteins, are defined as major food allergens. These foods account for the large majority of severe food allergic reactions:

• milk
• egg
• fish, such as bass, flounder, or cod
• Crustacean shellfish, such as crab, lobster, or shrimp
• tree nuts, such as almonds, pecans, or walnuts
• wheat
• peanuts
• soybeans
• sesame

The law requires that food labels identify the food source of all major food allergens used to make the food. This requirement is met if the common or usual name of an ingredient already identifies that allergen's food source name (for example, buttermilk). Otherwise, the allergen's food source must be declared at least once on the food label in one of two ways.

The name of the food source of a major allergen must appear:

In parentheses following the name of the ingredient.

Examples: "lecithin (soy)," "flour (wheat)," and "whey (milk)"

-OR-

Immediately after or next to the list of ingredients in a "contains" statement.

Example: "Contains Wheat, Milk, and Soy."

The “Contains” statement, if present, must list all allergens that are in the product. “So, if a ‘Contains’ statement has your allergen listed, put the food product back on the shelf,” says Carol D'Lima, food technologist with the Office of Nutrition and Food Labeling at the U.S. Food and Drug Administration.

However, not all allergen-containing products have a “Contains” statement. So, to be sure that an allergen is not present, consumers should always read all ingredient information on the label. “It’s very important to read the entire ingredient list to see if your allergen is present. If you see its name even once, it’s back to the shelf for that food product too.”

There are many different ingredients that contain the same major food allergen, but sometimes the ingredients’ names do not indicate their specific food sources. For example, casein, sodium caseinate, and whey are all milk proteins. Although the same allergen can be present in multiple ingredients, its “food source name” (for example, milk) must appear in the ingredient list just once to comply with labeling requirements.

Sesame was not a major food allergen under the Food Allergen Labeling and Consumer Protection Act of 2004. Sesame became the ninth  major food allergen in 2021 with the signing of the Food Allergy Safety, Treatment, Education and Research (FASTER) Act. As of January 1, 2023, sesame is required to be labeled as an allergen on food packages, including dietary supplements.  

Even though the requirement that sesame be listed on the label as an allergen is in effect as of January 1, 2023, you still may find food products for sale that don’t list sesame as an allergen on the label. 

The law does not require food products that were already on their way to the store or in stock before 2023 to list sesame as an allergen on the label. So for now, consumers may still want to check with the manufacturer.

Allergen labeling requirements for foods that aren’t packaged may vary, like bagels in a grocery bin or bakery goods displayed on trays. If you’re concerned about those products, you may want to ask store personnel for food allergen information. 

"Contains" and "May Contain" Have Different Meanings 

If a “Contains” statement appears on a food label, it must include the food source names of all major food allergens used as ingredients. For example, if “whey,” “egg yolks,” and a “natural flavor” that contained peanut proteins are listed as ingredients, the “Contains” statement must identify the words “milk,” “egg,” and “peanuts.”

Some manufacturers voluntarily include a separate advisory statement, such as “may contain”  or "produced in a facility," on their labels when there is a chance that a food allergen could be present. A manufacturer might use the same equipment to make different products. Even after cleaning this equipment, a small amount of an allergen (such as peanuts) that was used to make one product (such as cookies) may become part of another product (such as crackers). In this case, the cracker label might state “may contain peanuts.”

Be aware that the “may contain” statement is voluntary, says D'Lima. “Not all manufacturers use it.”

When in Doubt, Leave It Out

A food product's ingredients can be changed at any time, so D'Lima says it’s a good idea to check the label every time you buy the product — even if you have eaten it before and didn’t have an allergic reaction.

“If you’re unsure about whether a food product contains any ingredient to which you are sensitive, don’t buy it, or check with the manufacturer or distributor listed on the food product's label first to ask what it contains," says D'Lima. 

Peanut allergy is one of the most common food allergies. It often begins in childhood and usually lasts for life. Symptoms include hives, lip swelling, and trouble breathing. It can even be deadly.

Several years ago, an NIH-funded study found that kids who began eating foods with peanuts as infants were less likely to become allergic to them. By age 5, their risk of peanut allergy had dropped by 81% compared to kids who had avoided peanuts. Most of the peanut-eating kids stayed allergy-free up to age 6.

In a new follow-up study, researchers asked how long this protection could last. They tracked about 500 of the original study participants up to about age 13. They found that only one child in the peanut-eating group had developed a new peanut allergy.

Overall, less than 5% of the peanut-eating kids were allergic at age 13. For comparison, about 15% of the peanut-avoiding kids were allergic. Early and regular exposure to peanuts in childhood had reduced teens’ peanut allergy risk by 71%.

The results show that beginning to eat peanut products in infancy can have lasting benefits. But parents should talk with a doctor first. A doctor can test to make sure the child is not already allergic.

“If widely implemented, this safe, simple strategy could prevent tens of thousands of cases of peanut allergy in the United States each year,” says Dr. Jeanne Marrazzo, director of NIH’s National Institute of Allergy and Infectious Diseases.