What You Need to Know About Cashew Allergies

Though they are technically seeds, cashews are commonly classified as tree nuts. They can be found within the drupe (fleshy fruit) on the tropical tree species known as Anacardium occidentale.

Cashew allergies result when a person’s immune system reacts to the proteins found in cashews, causing allergy symptoms. A cashew allergy is a common tree nut allergy. Roughly 20% of all people allergic to tree nuts in the United States are allergic to cashews.

This article discusses the symptoms, risk factors, and treatments for cashew allergy.

Cashew Allergy Symptoms

Cashew allergy symptoms are the same as those that occur with other types of food allergies. They include:

• Hives, or a similar skin reaction known as angioedema
• Gastrointestinal symptoms, such as stomach ache, nausea, vomiting, and diarrhea
• Itchy skin
• Respiratory symptoms, such as shortness of breath, coughing, and wheezing
• Sneezing
• Hoarseness or tightness in the throat
  
• Itchy, swollen, or watery eyes
• Face or throat swelling
• Drops in blood pressure

Complications

Allergic reactions can sometimes be severe in nature and lead to more serious symptoms that require immediate medical attention.

When serious symptoms arise, anaphylaxis (a life-threatening allergic reaction) may occur.

Risk Factors 

There are several risk factors associated with developing an allergy to cashews. They include:

• Allergy to another type of tree nut: Tree nuts often have high cross-reactivity, which is when two different foods have similar enough proteins that cause allergic reactions. Pistachios, in particular, have a cross-reactivity with cashews.
• Peanut allergy: Since peanuts contain similar proteins as cashews, a person with a peanut allergy will likely also be allergic to cashews.
• Hereditary factors: In some cases, having immediate family members who are allergic to tree nuts may increase the risk of developing an allergy yourself.

Diagnosis 

Diagnosing a cashew allergy involves the same diagnostic parameters as other types of food allergies, including other tree nuts.

Typically, diagnosis begins with gathering symptoms or a medical history of allergic reactions after consuming cashews.

Other tests for cashew allergy include:

• Radioallergosorbent testing (RAST): The RAST test is a blood test that looks for specific antibodies produced in response to allergens (substances that cause allergic reactions).
• Skin prick test: The skin prick test is performed by a healthcare provider. The test uses a comb-like tool to prick the skin on your upper back or your forearm. The allergen is then introduced to the pricked area to see if there is a reaction.
• Oral food challenge: The oral food challenge involves a person with a suspected cashew allergy eating cashews in a controlled setting to see if there is a reaction. This challenge is done under direct medical supervision in case a severe allergic reaction occurs.

Treatment

The first-line option for treating a cashew allergy is complete avoidance. This means that cashews and potentially any other foods with cross-reactivity need to be avoided completely to prevent symptoms.

Antihistamines can be taken for mild symptoms as soon as a potential allergic reaction has occurred. However, treatment for severe allergic reactions should be carried at all times in case of an emergency.

What to Avoid

Along with cashews, you may have to avoid consuming other types of tree nuts as well. This is especially true for pistachios, since they have a high cross-reactivity with cashews.

Many food products contain hidden ingredients that could include cashews. Be wary of prepackaged foods that don’t have a "nut-free" label attached.

Nut butters, as well as oils and extracts, should also be avoided because they likely contain the protein allergen that is causing symptoms in someone with a cashew allergy.

You should also keep away from products that have a nut allergy warning label on them. These often include things like cookies, cakes, ice cream, and sauces.

Food Alternatives 

While it can be difficult not being able to eat cashews and other tree nuts, there are other food products that are safe to eat and taste just as good. These can include seeds, soybeans, chickpeas, and pretzels. These snacks offer the crunchy and salty flavor profile often found in cashews and other nuts without the risk of an allergic reaction.

When to See a Healthcare Provider

If you are experiencing mild symptoms of an allergic reaction after consuming cashews, you should contact your healthcare provider. They will be able to run the appropriate tests to determine if cashews are the cause of your symptoms.

You may be referred to an allergist (an allergy specialist) to help determine if cashews were the cause of your symptoms.

Summary

Cashews, though technically a seed, fall under the category of tree nuts. When a person is allergic to cashews, they can experience symptoms such as hives, swelling, difficulty breathing, and wheezing when they consume them. In severe cases, which often occur with cashew allergies, a life-threatening allergic reaction known as anaphylaxis can occur. This causes symptoms such as confusion, dizziness, or difficulty breathing.

Typically, if you are allergic to peanuts or another type of tree nut, you are also likely to be allergic to cashews. Being unaware of a cashew allergy puts you at risk of serious symptoms, so it's important to get diagnosed and receive a prescription for an emergency epinephrine auto-injector (EpiPen) for when you experience severe symptoms.

Avoiding all tree nuts, peanuts, and products that may contain traces of nuts is the best way to avoid an allergic reaction. You should read all your food labels prior to eating and seek out alternatives.

A Word From Verywell 

Having a cashew allergy is unfortunate because many people enjoy eating cashews. However, there is no cure for food allergies, so it's best to prevent them as best as you can. Food allergies are frustrating, but avoiding a certain food is much better than experiencing the sometimes life-threatening symptoms that can accompany an allergic reaction. Seek the guidance of a healthcare provider if you experience allergy symptoms after eating cashews.