How to Recognize Peanut Allergies

Three Parts:Tracking SymptomsConfirming a Peanut AllergyProtecting Someone with a Peanut Allergy

Peanut is one of the top-8 allergens which collectively account for 90% of all food allergies. The other seven are: Milk(dairy), Eggs, Fish with fins, shellfish, Tree nuts, Wheat and Soybeans. From a medical perspective peanut allergy can be treated like other food allergies in terms of symptoms, treatment and diagnosis testing. The societal response to Peanut allergy is highly contested and controversial in America.

Part 1
Tracking Symptoms

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    Observe symptoms that indicate an allergic reaction. Peanut butter is a staple food for school age children because of it's nutritional values and low cost. It's important to determine if your child is allergic before sending them to school where exposure is likely unless precautions are made in advance.
    • A young child with no family history of food allergies does not need a formal medical food allergy test regime.
      • Children of peanut allergic siblings were studied and assessed with an ImmunoCap study to check for the allergy to peanuts. The study indicated that a peanut allergy was markedly and significantly increased in siblings of peanut allergic patients.[1]
    • Allergies are believed to not appear until the 2nd exposure or later. Upon the first exposure the body may determine if the food is 'safe' or not, so small and gradual food introduction over weeks time may be the best approach, just like introducing any new food to a baby.
    • The mucus membranes may be sensitive if the person is highly allergic, so eating the food is not always a requirement to test. First check to see if you child has an aversion to the odor (sinus pain or sneezing), any skin reaction on the back of the hand, or any burning or tingling with the food on the lips.
    • With any high risk, top-8 food it's best to take it slow, because once the allergen is in the stomach, you aren't going to get it all out even if they vomit.
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    Follow these guidelines to recognize allergic reactions
    • It is commonly believed that peanut allergies tend to be more severe that other food allergies.
    • Some allergic responses to food can happen within about two hours of eating the food.[2] Others, such as anaphylaxis, can happen within minutes.
    • If the allergy symptoms are on the mild end of the scale, track how much time elapsed between eating the food and developing the symptoms.
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    Write down all the foods that the person ate in the hours leading up to the reaction, including amounts and ingredients.
    • Pay attention to other allergies. Between 25% and 35% of those allergic to peanuts have allergies to tree nuts as well. If the individual is presenting allergy symptoms when he eats tree nuts he may also be allergic to peanuts.
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    Check ingredient labels. If you suspect a peanut allergy, check the labels on foods that have been recently consumed. Peanuts are often included in processed and prepared foods or certain batches of food may be exposed to cross contamination in the factory.

Part 2
Confirming a Peanut Allergy

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    Visit an allergist or immunologist. If you or your doctor suspects you have a peanut allergy, you should make an appointment with an allergist or immunologist right away. This professional will first obtain a thorough history and physical. The focus of this appointment will be the response you experience when you encounter peanuts or tree nuts.
    • Accommodating food allergies can have a profound effect on lifestyle, quality of life and mental health. It is important to be prepared for a possible allergic reaction, but to also not live in fear based only on tests which may have false positive results.
    • Ask about possible desensitization treatments called Immunotherapy to reduce the risk of a severe reaction from a small accidental exposure. There are several different Immunotherapy protocols, some of which are still in clinical trials.
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    Go through allergy testing. There are several immunologic tests that can be administered to provoke the IgE response. This response will help assess the scope of the peanut allergy, but ultimately the only way to be absolutely certain is with an Oral Challenge test.
    • If the patient has had anaphylaxis previously the doctor may choose to start with blood testing to avoid the risk of triggering that reaction again. Typically skin prick testing is the first to be performed.
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    Take a skin prick test. This test involves exposing you to a potential allergen. The possibility exists that you may experience anaphylaxis. Therefore, this test is done under close supervision of a skilled allergist and immunologist who are also skilled at treating anaphylaxis.
    • The allergist will perform an initial diagnostic, exposing you to common allergens. A small amount of calibrated solution will be placed on the skin and a special tool will painlessly make a shallow scratch.
    • The allergist will diagram the scratch sites, to keep track of which area is injected with which allergen.
    • You will be monitored for any acute and dangerous response that requires immediate attention. Otherwise, the injection sites are checked for the presence of a “wheal,” or raised itchy area, which would indicate an allergy.
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    Take a blood test. The allergist will draw blood to be used for IgE response testing. This type of test has the benefit of causing no potential risk to the patient, as the patient is not exposed to the potential allergen. Blood testing tends to have some false positive results.
    • Ask if newer RAST or ImmunoCap blood testing for Peanut is available. The ImmunoCap test is a second generation RAST test that measures a person’s IgE levels to an allergen.
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      • These tests may not yet be covered by your medical insurance. Ask if you can pay out of pocket if you are interested or if your health clinic will not perform the test ask where else you can go to get tested.
      • The peanut protein is presented in the laboratory with the patient’s blood sample. Radio labeled human IgE human antibody is added and the antibodies will combine to the allergen. RAST testing is ranked on 0-6 scale. With zero indicating no sensitivity and six is highest sensitivity.
      • A RAST of 3 or less requires more specific testing such as an oral challenge to confirm the allergy.
    • It is important to ask about the rate of false positive results during basic blood or skin prick testing.
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    Take an oral challenge. This is the only way to be absolutely certain an allergy does not exist. Since most Peanut allergies are severe with a high risk of anaphylaxis this testing should only be done in a supervised medical environment that can provide emergency treatment if required.
    • You will start with small doses of the allergen, starting with exposure to only the lips before swallowing. After each dose there is a waiting period, then the next dose is increased until a certain threshold is reached or until a reaction occurs.
    • After the last dose you will need to wait four hours to ensure there is not reaction before you are released.
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    Use the double-blind placebo-controlled food challenge as a last resort. This test, called DBPCFC for short, is used to confirm a specific allergy. This is also the testing used to determine eligibility to participate in clinical trials. This test is costly and time-consuming.
    • The patient will need to go through two oral food challenges that are at least one week apart. In one challenge the patient is given allergen and in the other a placebo. Neither the patient nor the allergist knows which capsule has the allergen, which helps to eliminate the potential for false reactions. [3]
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    • It can be useful for avoiding unnecessary elimination diets by pinpointing the exact allergen that affects a person.[4]

Part 3
Protecting Someone with a Peanut Allergy

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    Get a prescription for an Epipen. An Epipen auto injects epinephrine to counteract an anaphylactic reaction. If there is the possibility of anaphylaxis, get a prescription for this medical device.
    • Be sure to always have your Epipen with you. For children, it is useful to have one at school and the other at home to bring with them wherever they go. Adults and adolescents should carry their Epipen with them at all times.
    • Discuss with your doctor the proper technique for injection.
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    Talk with family members, caregivers, and school officials about the allergy. It’s vital that you cultivate a community that can protect the individual with the peanut allergy. Take special care at school. A substantial proportion of food allergies occur in school, and these reactions can be fatal. Over a two-year period, schools can expect that approximately 18% of students with food allergies will have at least one reaction at school.[5]
    • Educate the school nurse, family members, and caregivers as to the prompt use of the Epipen in the event of possible ingestion of peanuts.
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    Read labels carefully. It’s important to become very familiar with how to read labels. Manufacturers are required to include peanuts on food labels if there is any exposure. This includes phrases such as “may contain peanuts” or “made in a facility that shares equipment that processes peanuts.”[6]
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    Expect a peanut allergy if the individual has an anaphylactic reaction. Anaphylaxis can be caused by more than just peanut allergies, such as bee stings.[7] Food allergies comprise the leading cause of anaphylaxis in children under age four who are given emergency medical help.[8] Assume that a person has a peanut allergy until he can be tested by an allergist.
    • In the United States, there are roughly 30,000 episodes of anaphylaxis, 2,000 hospitalizations, and 200 deaths per year.[9]
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    Get immediate medical attention with anaphylaxis. If an individual has an anaphylactic reaction, she should be taken to the emergency room immediately. She will also need an immediate injection of epinephrine from a medical device like an Epipen. [10] The doctor may perform one or more of the following procedures on the affected individual. In 90% of cases, these procedures will prevent the patient’s death from anaphylaxis.
    • The individual will receive an IV of epinephrine in the emergency room.
    • The patient will be placed on a ventilator if she is experiencing respiratory failure or laryngospasm, which indicates that respiratory failure is forthcoming. It is crucial that the person is intubated (a tube will be placed in the trachea) before the larynx begins spasms and will not permit intubation.[11]
    • The patient may receive H2-blockers such as Pepcid or Zantac via IV, which will decrease a histamine response.
    • The patient may receive blood pressure support with vasopressors if need be. [12]
    • Delays in recognition of anaphylaxis were associated with delays in administration of epinephrine. Even in cases where anaphylaxis was quickly identified and the patient was quickly treated with epinephrine injection, 10% still died.[13]
    • The person will likely be observed for several hours either on the medical wards or in the ER after the reaction, as a second, delayed response may manifest in a few hours. This observation period is vital to ensure a safe discharge.


  • Foods as potential allergens are the culprit in 90% of acute systemic reactions in children, with the most common foods being eggs, milk, soy, wheat products, and peanuts. Adults most often suffer a reaction to shellfish, peanuts and fish.[14]
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Sources and Citations

  1. Joel J Liem, Saital Huq, Anita Kozyrskyz, Should Younger Siblings of peanut -allergic patients be assessed by an allergist prior to be being fed peanuts?, Journal of Allergy and Clinical Immunology 2008, 4 144-149.
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Categories: Allergies and Immunization