Nut Allergy Reaction: What Triggers Nut Allergy?

A nut allergy reaction should always be taken seriously. Particularly in children, allergies to peanuts and hazelnuts sometimes trigger life-threatening allergic shocks. The good news is that emergency EpiPen kits, careful research – and soon perhaps new nut allergy treatment – can protect against these reactions.

If you’re a nut allergy sufferer, or a parent of one, you are most likely aware of the tedious process of studying ingredient lists on packaging and consequently reaching for the next food item – it seems that a lot of foods are labeled “May contain traces of nuts.” 

Because for some nut allergy sufferers, just a small amount of nut can trigger a severe nut allergy reaction – perhaps even anapyhlaxis. This is always a risk regardless of whether they eat a nut, or if nut residues are found in chocolate or a spread – or even on your partner’s lips.^[1]

In this article, you’ll learn which nuts commonly trigger allergies besides peanuts – for example, those responsible for a tree nut allergy. Find out what to do or expect if you experience nut allergy symptoms – especially, anaphylactic shock – and how to test yourself for food allergies. We also present recent scientific findings on oral immunotherapy, a new treatment that may soon cure peanut allergies.

What Is a Nut Allergy?

If we have an allergy, our immune system initiates defensive reactions to fight off substances that are actually harmless, leading to symptoms such as a cold, itchy eyes, or diarrhea.

Experts call substances that trigger allergies “allergens.” These are certain proteins found, for example, in pollen, insect venom, or peanuts, walnuts, hazelnuts, almonds, and other nuts.

To find out more about allergies in general – for example, symptoms, diagnosis, and the most common allergens – read our Health Portal article on food allergies and intolerances.

Can Nut Allergy Be Prevented?

For a long time, experts advised parents to keep young children away from typical allergy triggers such as nuts, even if they had not yet developed an allergy. But new studies suggest that children who eat peanuts at an early age are less likely to develop an allergy.

That’s why health authorities in the United States updated their peanut allergy management guidance in January 2018. The new recommendation for parents whose children are considered at risk for allergies because they suffer from dermatitis or an egg allergy is now to include food containing peanuts in your child’s diet between the ages of four and six months old. Before that, you should ensure your child takes an allergy test to make sure that your child does not already have a peanut allergy.^{[12, 13]}

Which Nuts Are Most Allergenic?

In a large-scale survey in the United States, researchers concluded that 1.4 percent of the US population is affected by peanut or tree nut allergy. More than half of the respondents suffered from peanut allergy.^[2]

Another study found that for US tree nut allergy sufferers, the most common triggers are walnut (34 percent), cashew nut (20 percent), almond (15 percent), pecan (9 percent), and pistachio (7 percent).^[3]

What Kind of Nut Is a Peanut?

Did you know that almonds and peanuts are not nuts at all? The peanut is a legume and is more closely related to beans and peas than to walnuts and hazelnuts. Experts therefore distinguish between peanuts and tree nuts, which include walnuts and hazelnuts, for example.

In scientific terms, we can categorize nuts into the following groups:

• Tree nuts: Walnut, hazelnut, macadamia
• Stone fruits: Cashew, coconut, almond, pecan, pistachio
• Capsule fruits: Brazil nuts
• Seeds: Pine nuts 

How Do They Test for Nut Allergies?

Doctors screen for allergies with the help of a blood test, for example. A laboratory tests your blood for certain antibodies, group E immunoglobins (IgE). These food allergy tests fifind out whether you are sensitized to an allergen – that is, whether several IgE antibodies against the allergen are found in your blood. Such blood tests can be done with a doctor, but there are also home test kits that screen for nut allergies.

Another way to detect sensitization to nuts is a prick test. In this testing method, a doctor places a liquid extract of the allergen or the allergen itself on your skin and checks for wheals and redness.^[32]

A provocation test can provide more certainty about whether you suffer from a nut allergy. Doctors administer a dose of the allergen to you or your child and observe whether a nut allergy reaction occurs. Since dangerous allergic reactions can also occur, this type of test must always take place under medical supervision.^[32]

If you find out you have a sensitivity to nuts through an IgE test, this is the first indication of an allergy. However, only physicians are allowed to make a concrete diagnosis – you should take your results to them to discuss.

Cross-Allergies: What Can You Eat When Allergic to Nuts?

The term “nut allergy” can be misleading – very few people are actually allergic to all nuts. Nevertheless, having a nut allergy makes having allergic reactions to other nuts more likely. Nuts can trigger cross-reactivity to other nuts; for someone who is allergic to peanuts, allergies to legumes such as lentils, beans, and soy are typical.^[4]

Tip: If you are allergic to several types of nuts, you can still enjoy pumpkin seeds, sunflower seeds, sesame seeds, poppy seeds, chia seeds, and flax seeds. Coconuts are also safe for most nut allergy sufferers.

Are Peanut Allergy Sufferers Also Allergic to Other Nuts?

Families in which children are allergic to one type of nut often ban all nuts from the house. The fear of an allergic shock is great – and understandably so. However, this can limit a nut allergy sufferer’s diet: After all, nuts provide valuable nutrients. They are rich in proteins, unsaturated fatty acids, and minerals such as calcium, magnesium, and iron.

In a US study, for example, 96 percent of the subjects who were allergic to peanuts were able to eat other nuts without any adverse side effects. Many participants who were allergic to walnuts or hazelnuts, for example, were also able to eat other nuts.^{[5, 6]}

If you are concerned about you or your loved ones trying certain foods or lacking certain nutrients, you should consider allergy testing and testing for nutrient deficiencies, such as magnesium deficiency or iron deficiency. These health tests can help you better assess allergies and keep your family’s diet safe and balanced.

What Are Common Nut Allergy Symptoms?

Typical nut allergy symptoms include the following:

• Skin changes: Tingling and itching in the mouth, redness, hives, swelling
• Respiratory symptoms: Sneezing, coughing, tightness in the throat, shortness of breath
• Digestive system: Vomiting and diarrhea

Nut Allergy Reaction: What Is an Anaphylactic Shock?

A particularly severe nut allergy reaction that can affect the entire body is called anaphylaxis. It can cause a life-threatening anaphylactic shock.

Anaphylactic shock is sometimes, but not always, preceded by warning signs. Those about to suffer an anaphylactic shock might experience the following possible nut allergy symptoms:^[15]

• Itching, burning, and tingling on the hands, soles of the feet, and genital area
• Tingling and itching on the tongue and top of the mouth
• Anxiety and headaches
• A metallic taste in the mouth

Children often become restless as well as anxious or aggressive before showing other symptoms.

What Are the Symptoms of Anaphylaxis?

Anaphylaxis primarily affects the skin, gastrointestinal tract, respiratory tract, and cardiovascular system. Symptoms can vary in severity, and they can occur as isolated symptoms or together. For example, circulatory problems may occur without a skin rash occurring first. Symptoms may be triggered quickly or develop over hours.

In mild anaphylactic reactions, only the skin is affected. People experiencing mild anaphylactic shock might suffer from itchy, red, and swollen skin – and throat and mouth.

Moderate nut allergy reactions are made noticeable through stomach complaints; such as nausea, vomiting, abdominal cramps, diarrhea, and involuntary bowel movements; breathing complaints such as a runny nose, hoarseness, and shortness of breath; and cardiovascular system complaints such as a faster pulse, falling blood pressure, and dizziness.

A severe anaphylactic shock can lead to respiratory arrest and circulatory shock, including unconsciousness and circulatory arrest – and can be fatal. However, deaths from food allergies are relatively rare. British scientists calculated that peanut allergy sufferers in the United Kingdom are more likely to die from an accident or even homicide than from anaphylactic shock.^{[16, 17]}

How Common Is Anaphylactic Shock from Nuts?

Food allergies – above all, those to peanuts – are the most frequent triggers of anaphylaxis for children and adolescents up to 17 years of age. For adults, food allergies come in third for anaphylaxis triggers, behind insect venoms and medications. Hazelnut and walnut are also among the top-ten triggers of anaphylaxis.^{[1, 4, 18]}

Seven Foods That Most Often Trigger Anaphylaxis

How Do I Prepare for a Nut Allergy Reaction?

Do you or your children have a severe allergy to dangerous allergens such as peanuts and tree nuts, or have you already experienced anaphylactic shock?

If so, your allergist can write you a prescription for an emergency kit containing important medications. The kit contains detailed written instructions that you, your child, or others can use to administer first aid.

What Should I Carry with Me in Case of Anaphylaxis?

With a severe anaphylactic shock, the hormone epinephrine is often the life-saving medication used. It raises your blood pressure to counteract circulatory shock. It also relaxes the muscles in the lungs, which can relieve shortness of breath. A typical allergy emergency kit contains one or two epinephrine auto-injectors – also known as an EpiPen. This allows sufferers or first-aid responders to inject epinephrine into the muscles on the outside of the thigh.^[19]

An emergency kit usually includes the following other items:^{[15, 20, 21]}

• An antihistamine is taken in the form of drops or tablets at the first signs of an allergic reaction. It is used to delay or suppress the allergic reaction itself.
• Glucocorticoids can also be used for mild symptoms. They work relatively slowly and are intended to prevent allergic reactions that occur later.
• In case asthma symptoms such as shortness of breath occur, the emergency kit contains bronchodilator inhalers and anti-inflammatory medication, which makes breathing easier.

Tip: Make sure that you regularly check expiration dates and whether you need to stock up on certain items in your kit.

What Can I Do as a Parent?

As a parent, you can help your child become an expert on their allergy and protect themselves from allergens:^{[22, 23]}

• Explain to your child exactly what to watch out for when eating – why they should not swap meals or taste other children’s food.

• Describe the warning signs of anaphylaxis to your child: If their hands, feet, or tongue itch or tingle, they should tell adults immediately.

• Inform relevant school/daycare centers and teachers about the allergy, anaphylactic shock, and emergency procedures.

• If there is a canteen in the facility, inform catering or the kitchen.

• Also inform other parents and ask them to avoid giving out candy, if possible, at events such as children’s birthday parties.

• Make sure your child always carries around their emergency kit and anaphylaxis emergency plan.

• Train teachers and other supervisors how to use the emergency kit.

• Give the relevant school or daycare center a written authorization that allows supervisors to use the adrenaline pen in case of emergency.

Nut Allergy Treatment: Will My Nut Allergy Go Away?

At the moment, there is no effective way to cure an allergy to peanuts or a tree nut allergy. Treatment consists primarily of avoiding the allergens. For milder symptoms such as red skin and an itchy mouth, you can take tablets or drops containing antihistamines. These medications are usually available over-the-counter at drugstores.

Does Immunotherapy Work for Nut Allergies?

As a peanut allergy sufferer, you can now hope for a cure in the future. Scientists are currently working on oral immunotherapy, whereby patients ingest peanut allergens orally. In one study, researchers gave children with peanut allergies peanut proteins along with probiotics, or lactic acid bacteria. Probiotics stimulate the immune system and are thus thought to enhance the effect of immunotherapy.

A total of 67 percent of the children were able to eat peanuts again after treatment; none of the children suffered anaphylactic shock for four years following treatment. The study was small, however, with only 24 children participating. Now the researchers want to test their method in larger studies.^{[28, 29]}

A recent review study that looked at 12 studies of oral immunotherapy for peanut allergy dampens our hopes somewhat. The risk of a severe nut allergy reaction such as anaphylaxis during treatment is still too high. According to the researchers, treatment still need to be improved and made safer.^[30]

Did you know that egg allergy and milk allergy affects mainly young children and disappear by the time they start school? Peanut allergy, however, only develops during adulthood in around 20 percent of those affected.^[31]

What Can Nut Allergy Sufferers Eat?

To replace the nutrients you’re missing from nuts, seeds make particularly ideal snacks because, similarly to nuts, they provide plenty of plant-based protein, B vitamins, vitamin E, magnesium, calcium, and iron.

Sunflower, pine nuts, and pumpkin seeds as well as flaxseed, sesame seeds, and poppy seeds are great nutrient-rich alternatives to nuts. They are not believed to trigger dangerous allergies.^[9]

The tigernut is very similar in taste to the almond, but it is a tuberous plant. This means you can turn to tigernuts as an alternative to nuts. Like nuts, it is rich in unsaturated fatty acids and fiber.^{[10, 11]}

How Do You Identify Allergens on Food Labels?

Food manufacturers are now required to mark the 14 most common allergens in bold print on ingredients lists. These include peanuts and tree nuts. Suppliers of loose goods, such as bakeries and restaurants, must also provide information about allergens in their products. The statement “May contain traces” is voluntary. More precise statements such as “May contain traces of hazelnuts” are rather rare.^[24]

Did you know that avoiding peanuts completely is difficult for many people. According to studies, 75 percent of peanut allergy sufferers accidentally ingest peanuts at least once over the course of ten years.^[25]

What Foods Should I Look Closely at?

You should be especially careful with highly processed foods and read the ingredients list carefully. This also applies to products you already know because manufacturers can change recipes at any time and do not have to announce this on the packaging.

Since trace information is voluntary, it’s a good idea to find out which manufacturers provide this information. It is better to avoid industrially processed products that do not contain any trace information – unless you are sure that the manufacturer otherwise always indicates trace information.

Typical Nut Allergy Reaction and Symptoms – at a Glance

What Is A Nut Allergy?

In a nut allergy, our immune system reacts to the allergens found in nuts. An allergy to peanuts and a tree nut allergy usually develops in infancy and remains in about 80 percent of cases through adulthood.

Which Nuts Are Most Allergenic?

In principle, one can be allergic to all kinds of nuts and seeds. Allergies to peanuts – which are actually not officially nuts at all, but legumes – are common. Walnuts and hazelnuts also often cause allergies. If you are allergic to one type of nut, this does not necessarily mean you are allergic to other nuts.

How Do Cross-Allergies Occur?

The allergens in nuts are similar to those in some other nuts, foods, and pollen. For example, peanuts can trigger cross-reactions with legumes such as lentils, beans, and soy. In turn, those who are allergic to walnut or hazelnut, for example, often react to other types of nuts as well.

What Are Typical Nut Allergy Symptoms?

Mild nut allergy reactions include skin irritation, tingling and itching in the mouth, sneezing and tightness in the throat, vomiting, and diarrhea. In children and adolescents, peanuts cause the most anaphylactic shocks. Hazelnuts and walnuts are also among the top-ten triggers of allergic reactions.

How Can I Treat a Nut Allergy?

The common treatment for nut allergies is to avoid the allergen and take antihistamines for milder symptoms. Researchers are working on oral immunotherapy that may cure peanut allergies in the future.

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