Peanut Allergy

Peanut allergy is a condition where the immune system mistakenly reacts to proteins in peanuts, leading to an allergic response. It is one of the most common food allergies, and one of the most common triggers of anaphylaxis. Even if you’ve had a mild reaction to peanuts in the past, it’s crucial to consult an allergist, as there is always a risk of a more severe reaction in the future.

Awareness of peanut allergies has grown significantly, which is why many schools have now adopted “nut-free” policies, where classic lunch items like peanut butter and jelly sandwiches are no longer allowed to ensure the safety of children with peanut allergies. A 2017 study found that peanut allergies in children had increased by 21 percent since 2010, with nearly 2.5 percent of U.S. children affected.

There are a few common misconceptions about peanut allergies. For example, peanuts are actually legumes, like soybeans, peas, and lentils, not tree nuts. And while many believe peanut allergies last a lifetime, research suggests that up to 20 percent of those with the allergy may eventually outgrow it.

What Causes Peanut Allergy?

A peanut allergy is caused when the immune system mistakenly identifies peanut proteins as harmful. Upon exposure to peanuts, the immune system releases chemicals into the bloodstream, triggering an allergic reaction.

There are a few ways that exposure to peanuts can occur:

• Direct Contact: The most common cause is eating peanuts or foods that contain peanuts. Even small amounts can cause a reaction in some individuals.
• Cross-Contact: This happens when peanuts accidentally come into contact with other foods, often during processing or handling. For example, a peanut-free food might be exposed to peanuts in a factory or kitchen.
• Airborne Inhalation: In some cases, breathing in airborne dust or aerosols containing peanuts, like peanut flour, can cause an allergic reaction.

See a Food Allergy Doctor

in St. Louis, Missouri

Peanut Allergy Foods to Avoid

Peanuts are common in many foods, making them challenging to avoid. Here are some foods that frequently contain peanuts to avoid:

• Ground or mixed nuts
• Baked goods like cookies and pastries
• Ice cream and frozen desserts
• Energy bars and granola
• Cereals and grain breads
• Marzipan (a nut-based candy)

Some foods may not obviously contain peanuts but could include peanut proteins due to their preparation or ingredients. These include:

• Salad dressings
• Chocolate candies and other nut butters
• Global dishes, especially African, Chinese, Indonesian, Mexican, Thai, and Vietnamese cuisines
• Foods from bakeries or ice cream shops, where cross-contact is common
• Arachis oil (another name for peanut oil)

If you cook from scratch, you can modify recipes to remove peanut ingredients, substituting them with alternatives like toasted oats, raisins, or seed-based products. Many people with peanut allergies can safely eat other nut or seed butters, but always check for cross-contact warnings on labels.

Peanut Oil Allergy

Most individuals with peanut allergies can safely consume highly refined peanut oil, as the refining process removes the peanut protein. However, unrefined peanut oils—such as cold-pressed, gourmet, or expeller-pressed—still contain peanut proteins and should be avoided. Consult with Dr. Cajigal to determine whether you should avoid all types of peanut oil.

Airborne Peanut Reactions

Although some people may feel anxious or experience symptoms like a rash when near peanut butter, studies suggest that simply being near peanuts or peanut butter doesn’t usually cause severe airborne peanut allergic reactions. However, inhaling airborne particles from ground or pulverized peanuts can pose a risk. If this is a concern, avoid environments where peanut dust could become airborne.

Peanut Allergy Symptoms

An allergic reaction to peanuts typically occurs within minutes of exposure. Signs and symptoms can vary in severity and peanut allergy symptoms may include:

• Skin Reactions: Hives, redness, or swelling.
• Itching or Tingling: Sensation in or around the mouth and throat.
• Digestive Problems: Diarrhea, stomach cramps, nausea, or vomiting.
• Breathing Issues: Shortness of breath, wheezing, or a runny nose.
• Throat Tightening: A feeling of tightness in the throat.

Peanut allergy can also cause anaphylaxis, requiring immediate treatment with an epinephrine autoinjector (such as an EpiPen) and emergency medical care. Signs and symptoms of anaphylaxis include:

• Airway Constriction: Difficulty breathing due to swelling of the lips, tongue, or throat.
• Shock: A severe drop in blood pressure.
• Rapid Pulse: An unusually fast heartbeat.
• Dizziness or Fainting: Feeling lightheaded, or losing consciousness.

Consult Dr. Cajigal if you or your child experiences any symptoms of a peanut allergy. Seek emergency medical help if a severe reaction occurs.

See a Food Allergy Doctor

in St. Louis, Missouri

Peanut Allergy Test

Diagnosing a peanut allergy begins with a discussion about your symptoms and medical history with your allergist. A physical examination often follows, and additional steps may be recommended to confirm the diagnosis:

• Food Diary: Dr. Cajigal might ask you to keep a food diary, recording your eating habits, any symptoms you experience, and the medications you take. This helps identify patterns that could point to a peanut allergy.
• Skin Test: During this test, a small amount of peanut extract is placed on your skin, which is then lightly pricked with a needle. If you’re allergic, a raised bump or reaction will appear at the test site.
• Blood Test: A blood test can measure your immune system’s response to peanuts by checking for allergy-specific antibodies, known as immunoglobulin E (IgE) antibodies. Elevated levels of IgE indicate a possible peanut allergy.
• Elimination Diet: If Dr. Cajigal suspects that you might be allergic to other foods besides peanuts, they may suggest an elimination diet. This involves removing peanuts and other potential allergens from your diet for a period of time. Afterward, you gradually reintroduce these foods, one by one, to see if symptoms reappear. However, this method isn’t safe if you’ve experienced severe reactions before.
• Oral Food Challenge: In some cases, your allergist may recommend an oral food challenge. This test is conducted in a medical setting where you are given small, increasing doses of peanuts. The allergist monitors you closely for any reactions, with emergency medication and equipment available if needed.

These peanut allergy tests help distinguish between a peanut allergy and other conditions, like food intolerances. Diagnosis can be complex, as symptoms vary from person to person and may differ between reactions.

If you suspect a peanut allergy, schedule an appointment with an allergist. Starting a food diary before your visit can be helpful. Be sure to note details such as:

• What (and how much) you ate.
• When symptoms began after eating the suspected food.
• What you did to alleviate the symptoms.
• How long it took for the symptoms to subside.
• This information will assist Dr. Cajigal in determining the most appropriate tests for diagnosing a peanut allergy.

See a Food Allergy Doctor

in St. Louis, Missouri

Peanut Allergy Prevention

In 2017, the National Institute for Allergy and Infectious Diseases (NIAID) released updated guidelines for preventing peanut allergies. These guidelines define high, moderate, and low-risk infants and provide recommendations for introducing peanuts based on the child’s risk level.

High-Risk Infants: These include babies with severe eczema, an egg allergy, or both. For these infants, the guidelines recommend introducing peanut-containing foods between 4-6 months of age, once they have started on solid foods and after determining it is safe to do so. High-risk infants should be tested for peanut allergies by an allergist using a skin or blood test before trying peanuts. If the test shows a small reaction, the allergist may recommend introducing peanuts in their office to ensure safety. However, if the skin test shows a large reaction (8 mm or larger), it may indicate an existing peanut allergy, and the allergist may advise avoiding peanuts.

Moderate-Risk Infants: Babies with mild to moderate eczema fall into this category. These infants do not require testing before trying peanut-containing foods. Parents can introduce peanut-containing foods at home starting around 6 months of age. It’s always a good idea to consult with a healthcare provider if there are any concerns.

Low-Risk Infants: Infants without eczema or egg allergy can have peanut-containing foods introduced at home according to the family’s preference, usually around 6 months of age.
Parents should note that most infants are either moderate- or low-risk for peanut allergies and can safely be introduced to peanuts at home. Whole peanuts should never be given to infants, as they pose a choking risk.

Peanut Allergy Avoidance

One of the most important steps in preventing an allergic reaction is knowing how to avoid peanuts and peanut-containing products. Here are some strategies to help you stay safe:

Read Food Labels Carefully: Always read labels on packaged foods to ensure they don’t contain peanuts or peanut products. U.S. regulations require manufacturers to clearly label products that contain peanuts, and many labels also include warnings like “may contain peanuts” or “made in a factory that processes peanuts.” Even if you’re familiar with a product, check the label each time, as ingredients can change.

Avoid Cross-Contact Risks: Even foods that don’t list peanuts as an ingredient can be contaminated during processing or preparation. If a label warns that a product was made in a facility that processes peanuts, it’s best to avoid it. Talk to Dr. Cajigal about the risks of consuming products with these voluntary cautionary labels.

When in Doubt, Say “No Thanks”: At restaurants and social gatherings, there’s always a chance of accidental exposure to peanuts. If you’re unsure about a food’s ingredients, it’s safer to avoid it. Many people may not realize how serious even a small amount of peanut can be for someone with an allergy.

Be Prepared for Reactions: Carry emergency medication, like an epinephrine autoinjector (EpiPen, Auvi-Q), and know how to use it. Discuss with your allergistr what to do in case of a reaction, and ensure that family and close friends are aware of your action plan.

Peanut Allergy Treatment

The standard approach for managing a peanut allergy is to avoid all foods that contain peanuts. However, researchers are exploring new therapies that may help reduce the risk of severe reactions, including anaphylaxis. Here’s an overview of some of these peanut allergy treatment options:

Immunotherapy

Immunotherapy aims to train the immune system to be less reactive to allergens like peanuts. This process, also known as desensitization, doesn’t cure peanut allergies or replace emergency treatments for anaphylaxis, but it can lower the risk of a severe reaction if accidental exposure occurs.

• Oral Immunotherapy (OIT): This involves gradually increasing doses of peanut protein under medical supervision. The goal is to help the immune system tolerate small amounts of peanut protein over time.
• Palforzia: This is an FDA-approved form of oral immunotherapy for children ages 4 to 17 with a confirmed peanut allergy. It’s taken daily to maintain tolerance, but it’s not a cure. Children must continue to avoid peanuts and carry epinephrine. Palforzia isn’t suitable for those with uncontrolled asthma or conditions like eosinophilic esophagitis.

Antibody Treatments

Antibody treatments for peanut allergy work differently from immunotherapy. These medications are given through injections and target specific proteins in the bloodstream that cause allergic reactions.

• Omalizumab (Xolair): This treatment binds to antibodies that trigger allergic responses, making the immune system less sensitive to peanuts. It may help reduce the severity of allergic reactions but is not a standalone solution for peanut allergy management.

Epinephrine

Since peanuts are common and accidental exposure is possible, it’s essential to be prepared for a reaction:

• Carry an Epinephrine Autoinjector: An epinephrine autoinjector (like an EpiPen) is a device that delivers a single dose of medication to counter severe allergic reactions. Always have it with you, keep a backup, and replace it before it expires. Make sure you know how to use it, and ensure those around you—like family, friends, and coworkers—know how to help in an emergency.
• Know When to Use Epinephrine: If you’re unsure whether to use your epinephrine, it’s often better to use it rather than wait. Talk to Dr. Cajigal about the signs that indicate you should administer the injection.

See a Food Allergy Doctor

in St. Louis, Missouri

Is There a Cure for Peanut Allergy?

Where peanut allergies persist, emerging treatments like oral immunotherapy (described above) can also help reduce the risk of a severe reaction if accidental exposure occurs, making it easier to live safely with a peanut allergy.

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