by | Apr 14, 2024 | Healthy Living
Why Are Peanut Allergies So Common?
Sweet caramel popcorn with salty peanuts has been your go-to favorite treat since childhood, but it’s now forbidden since you landed in the emergency room. You have an appointment with an allergist on your calendar and are now the reluctant owner of not one, but two epinephrine injector pens. Until you know for sure, avoiding anything that might have peanuts in it has become priority number one turning you into a reluctant detective.
Peanut allergies are in the top nine food allergies affecting the U.S. population and they are among the most severe of food allergies. Between 2010 and 2017, peanut allergies increased 21% among the nation’s children and estimates say that 2.5% of the nation’s children may have a peanut allergy. Each year 200,000 people in the U.S. require emergency treatment for food allergies, including those with adult onset. It’s not just the U.S., Peanut allergies are on the rise across Western nations.
Why Do People React to Peanuts?
Peanut allergy is one of the most common and potentially severe allergies. Scientists are still working to understand the processes and potential biological connections related to the development of peanut allergies. When a person has a reaction to pollen, their body mistakes pollen for an invader and goes into overdrive to attack it. Some fruits and vegetables contain a protein remarkably like certain pollens causing the same reaction. This same mechanism may be at play with peanuts because peanut proteins resembling pollen are not easily destroyed in the gut and may cross into the bloodstream. This may account for the extremely quick allergic reaction that can occur within minutes.
Doctors previously advised pregnant women to avoid ingesting peanuts and to withhold peanuts from young children before the age of three. That advice may have backfired and led to an increase in allergies. Recent research suggests that early exposure to peanuts allows children to develop a tolerance for them. Children with a severe egg allergy, severe eczema, or an older sibling who is allergic are at considerable risk of developing peanut allergy and should be tested around 4-6 months. Some children show allergy symptoms as early as 4 months, but many children don’t until they are between 12- 24 months. Only about 20% of children will naturally outgrow peanut allergies. Unlike egg or milk allergies, peanut allergies do not always decrease with age and often become more serious leading to anaphylaxis.
Anaphylaxis is a severe rapid onset allergic shock. This life-threatening whole-body response to an allergen may include swelling of the throat, impaired breathing, a sudden drop in blood pressure, pale skin or blue lips, fainting, and dizziness. These symptoms require immediate use of an epinephrine auto-injector and emergency medical treatment. Antihistamines will not stop an anaphylactic reaction. It is important to note that any who experience a severe case of anaphylaxis should be admitted to the hospital and monitored overnight until stable. Biphasic anaphylaxis may occur in some cases where symptoms recur up to 8 hours after the initial reaction.
If I’m Allergic to Peanuts, Am I Allergic to All Nuts?
Not necessarily. Although they are called nuts, peanuts aren’t true nuts that grow on trees such as almonds, walnuts, pecans, and other nuts. Peanuts are part of the legume family—think peas, soybeans, and lentils. While fewer than 10% of people outgrow tree nut allergies, 20% of those with peanut allergies might. Of those allergic to peanuts, 25% to 40% also react to at least one tree nut.
Potential Factors Leading to the Rise in Peanut Allergies:
If a sibling or parent is allergic to peanuts, the odds of a child also being allergic increase. The odds increase even more if both parents are allergic. About 20% of peanut allergies have links to certain gene regions at the chromosomal level. Other factors include:
Hygiene
It is suspected that increased peanut allergies are related to improved hygiene and daily washing with soap which may make it easier for peanut proteins to bypass the digestive system and penetrate the skin.
The hygiene hypothesis theory suggests that as lifestyles have trended toward indoor and cleaner living as well as the availability of medications that quickly treat infections, our immune systems become more prone to attack the harmless proteins found in pollen, foods, and animal dander. The theory is that children exposed to fewer germs have immune systems that fail to develop properly and are unable to differentiate between the harmful and harmless. This immune confusion leads to the development of allergies. The same mechanisms that fight allergies also fight parasites. Less exposure to parasites may lead to the immune system turning against things that it would otherwise deem harmless.
As family sizes have shrunk and access to clean water has increased, it has become common to wash babies daily, which was not the norm 50 or even 25 years ago. It could be that skin permeability to foreign proteins has changed and might be reversible if habits change.
Vitamin D
A lack of Vitamin D is another potential contributor to peanut allergies. Vitamin D is critical in maintaining the immune system; however, many do not get enough of it. In the U.S., the rate of those who are deficient has nearly doubled over a decade. An under-supported immune system can lead to more susceptibility toward allergic reactions.
Allergen Exposure
Other food allergy theories center around early versus delayed introduction to certain foods along with preparation and how that might impact the body’s tolerance.
The “dual allergen exposure” theory suggests that a balance between time of introduction, dose, and form of exposure impacts food allergy development. The thinking is if a child eats trigger foods as they wean it can lead to the prevention of an allergic response because the gut is prepared to tolerate bacteria and new substances. This becomes more important if a baby has eczema as allergy antibodies can develop through exposure via broken skin.
King’s College London conducted a study that found an 80% reduction in peanut allergies among 5-year-old children who regularly consumed peanut butter during their first year. The findings led to adjustments in the U.S. dietary guidelines regarding infant peanut consumption.
Symptoms of a peanut allergy may include:
- Hives
- Tingling or itching of the mouth
- Vomiting
- Swelling that can affect the tongue and/or lips, around the eyes
- Stomach cramps, indigestion, diarrhea
- Itchy/watery eyes, runny nose
- Sneezing, coughing
- Wheezing, shortness of breath, difficulty breathing
- Repetitive cough
- Tightness in throat, hoarse voice
- Weak pulse
- Pale or blue coloring of the skin
- Dizziness/fainting
- Confusion
- Low blood pressure
Children between 4yo and 17yo who have a documented allergy may benefit from peanut oral immunotherapy or epicutaneous therapy where tiny amounts of peanut are introduced over time to build up tolerance and reduce the risk of severe reaction or anaphylaxis. These treatments are not without side effects—aside from the potential for anaphylaxis, resulting damage to the tissue of the esophagus can make it hard to swallow. Even with this treatment, it is crucial to avoid peanuts and carry two epinephrine auto-injectors to avoid an anaphylactic response.
What Foods Have Peanuts?
Peanut proteins are in many foods, so it’s important to read labels and recognize where they might lurk. Fortunately, in the U.S., the Food Allergen Labeling and Consumer Protection Act of 2004 requires manufacturers of packaged food to clearly label peanut-containing products.
Peanuts can be found in:
- Candy
- Cookies
- Ice cream
- Snack foods
- Sauces (as a thickener)
- African, Mexican, and Asian (Thai, Chinese, Indonesian, Vietnamese) cuisine
Exposure to peanuts is possible through surface cross-contamination of restaurant surfaces even if your dish has no peanuts. Those who are gluten-free should watch out for lupine which is a common flour substitute due to an unusually strong possibility of a cross-reaction between it and peanuts.
Some lawn fertilizing composts use peanut shells so be sure to check the label or ask your contractor to avoid their use.
What Should I Do If I Suspect An Allergy?
If you suspect a peanut allergy, the most reliable method for testing is a clinician-supervised oral food challenge. Keeping a food diary before your allergist appointment to track any reactions will also be helpful.
- What you ate (and how much)
- When the symptoms started (after eating the suspected food)
- What you did that relieved the symptoms
- How long it took before the symptoms were relieved
If you are dealing with regular allergies, visit AFC Urgent Care Knoxville to discuss the next steps to prevent you from suffering from a peanut allergy.
