Peanut Allergy - Diagnosis and Treatment

Diagnosis

Healthcare professionals begin by gathering information about the person’s symptoms, past health, and possible reactions to peanuts or foods containing them.

This first step helps determine if the immune system overreacts to peanut protein, which can trigger allergic reactions such as hives, swelling, or even anaphylaxis.

After the initial assessment, doctors perform a physical check-up and order specific tests. Some doctors ask patients to keep a food diary to record what they eat, any symptoms that appear, and medicines taken.

This record can reveal patterns that link peanut foods to allergic symptoms like abdominal pain, hives, or breathing issues, especially in children and adolescents.

Allergy testing confirms a diagnosis. Common methods include:

Test Name	Description
Skin Prick Test	Doctors place small drops of peanut or other allergens on the skin and prick it. If a red bump forms, this may signal a peanut allergy.
Blood Test (IgE Levels)	A blood sample checks if the body makes IgE antibodies against peanut proteins. Higher levels may point to an allergy.
Elimination Diet	Doctors remove peanuts and other possible foods from the diet and then slowly add them back in to watch for allergic reactions.
Oral Food Challenge	Under medical supervision, patients eat small amounts of peanut so doctors can monitor for any severe allergic reactions or symptoms.

Doctors use these steps to rule out food intolerance and identify other conditions, like eosinophilic gastrointestinal disease or asthma, that have similar signs.

Treatment

Building Tolerance with Immune System Training

Immunotherapy helps the immune system become less sensitive to peanuts. One main option is oral immunotherapy, where patients take small, measured amounts of peanut protein by mouth.

Doctors gradually increase the dose—a process called “up-dosing”—to help the body get used to peanuts without a reaction.

The FDA has approved a type of oral immunotherapy called peanut allergen powder, sold as Palforzia. This treatment is available for children aged 4 to 17 who have a doctor-confirmed peanut allergy.

It is not suitable for everyone. For example, children with uncontrolled asthma or certain digestive illnesses, such as eosinophilic esophagitis, should not use it.

Immunotherapy aims to lower the risk of severe reactions if someone accidentally eats peanuts, not to cure the allergy. Patients still need to avoid peanuts and keep emergency medicine with them.

Because treatments can cause side effects or trigger allergic reactions ranging from mild to severe, therapy is always started and adjusted in a medical setting.

Antibody Treatments to Lessen Allergic Response

Doctors may use antibody-based treatments known as monoclonal antibodies. These are typically given as injections and work by blocking the action of immunoglobulin E (IgE), a protein involved in allergic reactions.

By reducing how much the body reacts to peanuts, antibody treatments may lower the chance of serious reactions.

These medicines do not replace other methods, such as carrying emergency medicine or avoiding peanuts. Doctors may use them together with other treatments, like oral immunotherapy.

Steps to Stay Ready for Accidental Peanut Exposure

People with peanut allergies must have a clear plan in place in case of a reaction, as completely staying away from peanuts is difficult and accidental exposure can occur.

Action Plan Checklist:

Always check food labels for peanut ingredients.
Tell others about the allergy, especially in restaurants or at school.
Carry emergency medicine, like epinephrine, wherever you go.
Recognize early signs of a reaction, such as rash, swelling, trouble breathing, or stomach pain.
Use antihistamines for mild symptoms, but be prepared to use stronger medicine if needed.

Emergency medicines:

Epinephrine: The most important treatment for a severe reaction (anaphylaxis).
Antihistamines: Help with mild symptoms such as hives or itching, but do not treat severe reactions.

Understanding and Using Your Emergency Medicine Device

If your doctor prescribes an epinephrine autoinjector, knowing how to use it can save lives.

Tips for proper use:

Keep It Handy: Carry it everywhere, including school, work, or outings. Consider keeping extra devices in common places.
Replace Before It Expires: Do not use expired epinephrine, as it may not work.
Have a Backup: Ask your healthcare provider for a second device in case one is lost or used.
Practice: Learn how to use the autoinjector. Ask for a training device and practice with your healthcare provider.
Educate Others: Family, friends, and caregivers should know how and when to use it too.

When to use your autoinjector:

If you notice trouble breathing, swelling, or other signs of a serious reaction.
When in doubt—using epinephrine is almost always safer than waiting.

Tips for Daily Management and Support

Managing peanut allergy can be challenging, but strong support and planning help reduce risks.

Families should make sure everyone who cares for the child—such as relatives, babysitters, and teachers—knows how to identify and react to an allergic reaction.

Action	Who Should Be Involved	Purpose
Written allergy plan	Family, caregivers, school	Clear steps and contacts for emergencies
No food sharing	Child, teachers, friends	Lower risk of accidental exposure
Epinephrine availability	All caregivers	Fast response to allergic reactions
Medical alert bracelet/necklace	Child, adults	Share allergy info in emergencies

A detailed written allergy care plan is important for safety.

This plan should outline steps to take if a reaction happens, the order of any needed medicines and the right doses, as well as phone numbers for family and healthcare professionals.

Each person responsible for the child should get a copy of this plan.

Discouraging food sharing helps lower the risk of accidental exposure. Children need reminders not to take or swap snacks, especially at school or during playdates, to prevent mix-ups with foods that might contain peanuts.

Epinephrine autoinjectors must always be kept close by. All caregivers, including teachers and after-school staff, need to know where the device is stored, when to use it, and accurate instructions for use.

Practicing with a training device can prepare them to act quickly.

Schools should put safety plans in place for students with peanut allergies. Staff training and guidelines, including access to emergency medication, help keep allergic students safer during school hours.

Wearing a medical alert bracelet or necklace is another helpful step. These items share key information, such as the child’s name and peanut allergy status.

Some bracelets even include urgent instructions, making it easier for medical teams to respond if the child can’t communicate during a reaction.

Getting Ready for Your Visit

How Your Doctor Will Assess Your Situation

During the appointment, the healthcare provider—often an allergist—will ask several targeted questions to better understand the possible peanut allergy. Some common questions include:

When did symptoms start, and what were they?
How soon after eating peanuts or peanut-containing foods did the symptoms appear?
What amount of peanuts or peanut-containing food was eaten?
Were any over-the-counter allergy drugs, like antihistamines, taken? Did they make a difference?
Do reactions only happen with peanuts, or with other foods too?
How intense or mild were the symptoms?
What actions, if any, helped to relieve the symptoms?
What seemed to make the symptoms worse?

The provider may also discuss further testing, possible treatments, and whether a referral to a specialist is needed.

Tip: Bring a trusted family member or friend with you. Having someone else in the room can help remember important information and questions.

Table: Questions an Allergist May Ask

Topic	Example Question
Timing of symptoms	“When did you notice symptoms after eating peanuts?”
Amount consumed	“How many peanuts or how much peanut product did you eat?”
Medication use	“Did you take any allergy medication? Did it help?”
Other food triggers	“Do other foods cause similar reactions?”
Symptom severity	“How serious were your symptoms?”
Symptom management	“What has made your symptoms better or worse?”

Steps to Take Before the Appointment

Getting ready ahead of time helps make the most of the visit. Use this checklist to prepare:

Write Down Symptoms: Note what happened after eating peanuts, how fast the reaction started, and how much you ate.
List All Medicines: Include prescription drugs, over-the-counter medicines, vitamins, and herbal supplements.
Prepare Questions: Make a list to bring, such as:
- Could peanuts cause my symptoms?
- Are there other possible reasons for my reactions?
- What tests do I need?
- What treatments can I use?
- Will I need to carry an epinephrine autoinjector?
- Should I speak to a specialist for more help?
- Are there helpful brochures, handouts, or trusted websites?
Think About Children: For parents, write down questions about safe food choices for your child, how to manage allergies at school, and the chances of outgrowing the allergy.
Bring a Support Person: Ask a friend or family member to come along to help remember details or offer support during the discussion.

What to Avoid Before the Visit:

Do not eat peanuts or foods with peanuts.
Until you confirm or rule out an allergy, avoid foods that could trigger a reaction.
If you have a severe allergic reaction, seek emergency help right away.

Peanut Allergy – Diagnosis and Treatment