Peanut allergy can be an incredibly serious issue that requires emergency treatment. Countering this health concern is a new treatment option, as well as other ongoing studies for the development of additional options that aim to help individuals with a peanut allergy have a lessened allergic response to peanut exposure. Peanut allergy continues to be one of the most prevalent food allergies, and its incidence rate in the US has been rising. In 1999, it was estimated to affect 0.4% of children and 0.7% of adults. In 2010, the incidence had increased to approximately 2% of children.¹ A study in 2017 found that 2.5% of children in the US may have the allergy.²

It should be noted that peanuts are not in the same plant family as tree nuts (eg, cashews, almonds, walnuts). They are part of a different plant family called legumes, which includes such things as beans, peas, and lentils. An allergy to peanuts does not increase the incidence of being allergic to other legumes.³ Although development of a peanut allergy usually lasts a lifetime, studies have shown that 20% of children outgrow their allergy.^3,4

There are multiple ways individuals can have exposure to peanuts. This can be through direct contact (eg, skin contact, ingestion), cross-contamination (eg, food exposed to peanuts during preparation or handling), or inhalation (eg, inhaling a dust or aerosol containing peanuts such as peanut oil or peanut flour).⁵ Any person who has an allergy to peanuts should not ingest any substance containing them. However, he or she must also be mindful that foods that do not contain peanuts can also be contaminated with peanuts during the manufacturing process or food preparation. An individual must read food labels to identify if the product contains a peanut warning.² 

Several risk factors may increase the propensity of an individual to develop a peanut allergy. This includes the age of the patient; a young child such as a toddler is at an increased risk as compared to an older individual with a more mature digestive system. An individual who has had a previous allergy to peanuts and has appeared to outgrow it may be at risk of it recurring in the future. If an individual has other allergies (eg, other food allergies, hay fever), he or she may be at increased risk for developing a peanut allergy. Also, people who have a family history of allergies, especially food allergies and individuals who have atopic dermatitis, are at increased risk for developing a peanut allergy.⁵ It is recommended that if a severe allergic reaction to peanuts occurs, the patient or caregiver immediately injects epinephrine early on during the reaction. It is also advised that people who have a peanut allergy carry an epinephrine auto-injector (eg, EpiPen, Auvi-Q) with them at all times.^6,7

Symptoms of an allergic reaction to peanuts may include vomiting, diarrhea, indigestion, stomach cramps, wheezing, breathing complications, dizziness, confusion, indigestion, continuous coughing, tightening of the throat, voice hoarseness, weakened pulse, paleness or blue coloring of the skin, hives, swelling that may include the lips or tongue, dizziness, and confusion.² Diagnosis of peanut allergy usually includes taking a detailed history of the person, skin prick testing, a blood test that measures the amount of allergy type antibodies known as IgE in the blood, and an oral food challenge.⁶ A skin prick test is when a healthcare professional places a small amount of the food allergen on the skin. The skin is then lightly pricked, and then the patient is monitored to identify whether a reaction or a bump develops on the skin, usually within 30 minutes.^7,8 An oral food challenge is when a healthcare professional within a clinical setting begins to orally administer a small amount of peanut to the individual and then monitors for a reaction. The clinician then slowly increases the amount until a reaction is observed. The food challenge is stopped once symptoms are seen.⁹

In January 2020, the FDA approved the first treatment for peanut allergies, an oral immunotherapy called Palforzia (peanut [Arachis hypogaea] allergen powder-dnfp). Palforzia is indicated for the mitigation of allergic reactions, including anaphylaxis that may occur due to accidental peanut exposure in patients aged 4-17 years who have a confirmed peanut allergy diagnosis.^10,11 Palforzia may be continued in patients aged 18 years and older. This therapy is indicated for use in conjunction with a peanut-avoidant diet.¹² It is composed of a specially designed powder made from peanuts.¹³ Palforzia is a treatment taken in very small amounts daily and gradually increased. This should result in a less severe allergic reaction to peanuts over time.¹³ Palforzia contains a boxed warning stating it can cause anaphylaxis at any time during therapy and is only available through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called Palforzia REMS.¹¹

In February 2015, results from a study called Learning Early About Peanut (LEAP) were published in the New England Journal of Medicine.^1,14 The LEAP study found that introducing foods containing peanuts to infants at high risk of developing peanut allergy was safe and that there was an 81% relative reduction in the subsequent development of a peanut allergy. The results of this study led to an update to the 2010 Guidelines for the Diagnosis and Management of Food Allergy in the United States that was published in January 2017, called Addendum Guidelines for the Prevention of Peanut Allergy in the United States.¹⁴ Addendum guideline 1 recommends that infants determined to be at high risk of developing peanut allergy due to having severe eczema, egg allergy, or both should be introduced to peanut in their diets as early as 4-6 months to reduce the risk of peanut allergy. It is recommended that the child’s healthcare provider guide this process.¹⁵ Addendum guideline 2 recommends that infants with mild to moderate eczema should have peanut-containing foods introduced into their diets at around 6 months to reduce the risk of peanut allergy. Addendum guideline 3 recommends that infants without eczema or any food allergy have foods containing peanuts freely introduced into their diets. In all of these cases, it is recommended that other solid foods should be started in infants before introducing peanut-containing foods.¹⁵

Finally, in November 2019, the Journal of Allergy and Clinical Immunology published a small study that evaluated the safety and efficacy of extended peanut sublingual immunotherapy (SLIT) in children ages 1 to 11. The SLIT study found that two-thirds of children who had a peanut allergy and received daily doses of dissolved peanut protein administered under the tongue were able after several years of treatment to tolerate eating about 2.5 peanut kernels. However, more extensive studies are needed to determine the safety and efficacy of this type of therapy.^16-18