Getting a nut allergy test is the right step forward if you suspect that you might be allergic to tree nuts. Unfortunately, the incidence of tree nut allergies has gone up in the last 10 years across the world. Nuts are now one of the most common and serious food allergens affecting both children and adults.
These allergies can often trigger severe and potentially life-threatening reactions. This makes it crucial for individuals to identify and manage their condition accurately. Unlike some food allergies that children may outgrow, tree nut allergies tend to persist into adulthood so it is very important to obtain an early diagnosis and be aware of the potential dangers. A recent study has shown that only 4% of children outgrow their tree nut allergy.
The challenge with tree nut allergies lies not only in their prevalence but also in the complexity of avoiding tree nuts. They are often found in a wide range of foods, from the obvious snacks and desserts to the less apparent ingredients in sauces and dressings. We have unfortunately seen numerous cases in the news where someone allergic to nuts had food that wasn’t properly labeled.
In severe cases, even trace amounts of tree nuts can provoke a serious allergic reaction such as anaphylaxis. This requires extra vigilance when eating out or buying takeaway food. It also means that these individuals need to carry an EpiPen with them at all times.
What are Tree Nuts?
Tree Nuts consist of the following common ones:
- Almond
- Brazil Nuts
- Cashew
- Hazelnuts
- Macadamia Nuts
- Pecan
- Pine Nuts
- Pistachios
- Walnuts
Peanuts are not tree nuts. Instead of growing in the tree, peanuts are legumes that grow underground.
Each tree nut comes from a different type of tree. Although known for their dense and healthy nutritional content, offering a rich source of fats, proteins, vitamins, and minerals, they could pose significant health risks.
We must also distinguish tree nuts from seeds, such as sunflower or sesame seeds, which some people can consume without issue even if they have tree nut allergies.
The distinction between tree nuts and peanuts is equally vital. Peanuts are often processed in facilities that also handle tree nuts. This could lead to cross-contamination and could pose a risk for individuals with severe allergies to either or both.
Foods that commonly contain tree nuts
You should be aware that certain foods you can buy from supermarkets or other shops may inadvertently contain tree nuts. You should always read the labels, but here are some of the common foods:
| Food Category | Examples |
|---|---|
| Baked Goods | Cookies, pastries, cakes, pies, and bread may use tree nuts as ingredients or garnishes. |
| Candies and Chocolates | Chocolate bars, truffles, and candies that often include tree nuts or are produced in facilities using tree nuts. |
| Snack Foods | Trail mixes, marzipan, granola bars, and crackers that may contain tree nuts or similar ingredients that may cross react. |
| Dairy Products | Ice creams and yogurts may use tree nuts as flavourings or additives to improve texture. |
| Salads and Dressings | Salads that include tree nuts as toppings; dressings and sauces that may use tree nut oils or different pastes. |
| Meat Products | Processed meats or dishes that may use tree nuts in marinades or stuffing. |
| Vegetarian/Vegan Products | Meat substitutes may also use tree nuts as a protein source or binding ingredient. Almond milk, hazelnut milk etc should also be avoided. |
| Ethnic Cuisines | Certain Asian, Mediterranean, and Middle Eastern dishes traditionally include tree nuts. |
What causes tree nut allergy?
Tree nut allergy is an adverse immune response to the proteins found in tree nuts. Essentially, the tree nut proteins are wrongly identified as being a harmful pathogen by the immune system. When this happens, it triggers an allergic reaction. The response from this vary from mild to severe, but more on the symptoms below.
Cross-reactivity Among Tree Nuts
Cross-reactivity happens when the proteins in one tree nut are similar in structure to those in another. The immune system cannot differentiate between the two, so it will react to both. This is why individuals with an allergy to one type of tree nut are often advised to avoid all tree nuts.
When someone has a tree nut allergy test, this is often done for groups of nuts at one time rather than individually. Similar to tree pollen, the allergens are grouped with trees that may be in season at the same time.
Cross-reactivity with Other Foods
People with tree nut allergy may also experience reactions to certain fruits, seeds, or legumes. This is again due to the similarity in protein structure and is known as oral allergy syndrome (OAS). Common cross-reactive foods include soybeans, peanuts, and certain fruits like kiwi and avocado.
This is why it’s important to have food allergy testing done on a wide panel of allergens.
Symptoms of tree nut allergy
Symptoms can range from mild to severe. They can affect the skin, GI tract, respiratory system, and in more severe cases even the cardiovascular system.
| Category | Symptoms |
|---|---|
| Skin | Hives or eczema in mild cases. Swelling of the lips, face, tongue, throat, or other parts of the body can also occur in more severe cases. The latter is known as angioedema and can escalate to anaphylaxis if not treated. |
| GI Tract (Stomach and Bowels) | Nausea and vomiting; Diarrhoea; Abdominal cramps |
| Respiratory (Lungs) | Sneezing; Nasal congestion or runny nose; Shortness of breath; Wheezing; Coughing; Itchy throat |
| Cardiovascular (Heart and Circulation) | Dizziness or fainting tends to occur due to a drop in blood pressure and perhaps a faster heart rate. |
| Severe Reactions (Affecting the whole body) | Anaphylaxis: rapid, weak pulse; severe drop in blood pressure; severe shortness of breath; loss of consciousness and eventually cardiac arrest if not treated promptly. |
Recognizing Anaphylaxis
Due to its life threatening potential, recognising the signs of anaphylaxis is very important. Any combination of the above symptoms could come up after exposure to a potential food allergen such as tree nuts. It’s therefore critical to seek emergency medical care immediately if you suspect that someone may have ingested something they are allergic to. An EpiPen may also have to be used in this case if available and the person should be continuously monitored until emergency help arrives.
Tree Nut Allergy Test
Diagnosis and managing tree nut allergies is done by an allergy specialist.
At Holistic Allergy, we can do skin prick tests or a blood test to check whether you are allergic to tree nuts.
1. Medical History and Symptom assessment
First, we will ask you about your history of reactions, types of symptoms experienced, their severity, and the timing of their occurrence relative to exposure to tree nuts.
We also need to establish your usual diet and specific incidents of other potential allergic reactions. This helps to pinpoint potential triggers and assess the risk of tree nut allergy. Due to cross-reactivity with other food items, this is especially important to ensure that we test you for all the potential allergens.
2. Allergy Testing
The nut allergy test component can involve a skin prick test, a blood test, or an oral food challenge.
Skin prick testing
Skin prick testing is the gold standard for allergy diagnosis. A small amount of different tree nut extracts is placed on your skin, which is then pricked just enough to help the allergen penetrate the top skin layer. If a raised, itchy bump (similar to a mosquito bite) develops within 15-20 minutes, it indicates an allergic reaction.
IgE blood test
This is a blood test that can identify the blood levels of IgE antibodies to specific tree nuts. If raised, this tends to indicate an allergy to the tested nuts.
Oral food challenge
An oral food challenge involves consuming small, increasing amounts of the suspected allergen under medical supervision. It’s performed in a controlled clinical setting to ensure safety, as there is a risk of triggering a severe allergic reaction. The risk will vary depending on what kind of allergic reaction you have had in the past. In cases of previous anaphylaxis, for example, it may not be indicated as the risk is too high. One of the other tests will have to be performed first. This is why an initial consultation going through your history and symptoms with a specialist is so important.
Managing a tree nut allergy
Here are some tips on managing your tree nut allergy once this has been established:
Know your nuts
Familiarise yourself with the types of tree nuts and their common names. It is now a legal requirement for food manufacturers to declare whether the food contains nuts or may be at risk of contamination. You must be able to identify the different types of tree nuts from the labels and recognise if you might be allergic to them.
Also, be aware of the risk of cross-contamination in processed foods and environments like restaurants or bakeries.
Communicate your allergies
When eating out, inform the waiter/waitress or chef of your allergy and ask about their cross-contamination policies. Be specific about which nuts you’re allergic to and the seriousness of your allergy.
Also, be aware of this when attending events where food or canapes are served. You may need to ask specifically or check with the organisers. Avoiding buffets may also help as the risk of cross-contamination here is higher.
Be well prepared for accidental exposures
if diagnosed with a tree nut allergy, you should be issued an EpiPen and be taught how to use it (usually by your GP or pharmacist). These are adrenaline auto injectors that can be life savers.
Also consider educating your friends, family, and those close to you about recognising an allergic reaction and what to do in case of an emergency.
Treatment options for tree nut allergy
The mainstay of managing tree nut allergy involves avoiding tree nuts altogether and being prepared to treat accidental exposures. While there is no cure for tree nut allergies, there are several treatments that can help manage symptoms and protect against severe reactions.
Antihistamines
Antihistamines can be used in cases of mild allergy symptoms, such as itching or hives. They are not effective in treating anaphylaxis and should not be used as a substitute for epinephrine in severe reactions.
Immunotherapy
Oral immunotherapy for tree nut allergy is an option for certain tree nuts only. The process involves administering small, increasing amounts of the allergen orally to build up tolerance over time.
Although Palforzia immunotherapy is now approved by MHRA and available for peanut allergy, immunotherapy for tree nuts is not as widely available. We hope to soon be able to offer desensitisation to tree nuts.
Ultimately, if you suspect that you might have a tree nut allergy, you should contact an allergist for a tree nut allergy test. At Holistic Allergy in Bournemouth, we can conduct allergy testing for anyone over 16 years old. Get in touch with us today to make a booking.
