Life with a Cashew Allergy: Learning, Managing, and Thriving

While technically classified as a seed allergy, cashew allergies are often treated as nut allergies due to their similarity to tree nuts. In individuals with cashew allergies, the immune system reacts to these seeds, triggering a spectrum of mild to severe allergic responses. This article delves into research findings and real-life experiences to provide insights into the symptoms, various treatment options, and effective management practices for those dealing with cashew allergies.

A large pile of cashew nuts on a solid white surface.

Understanding a Cashew Allergy


A cashew allergy is characterized by the immune system reacting adversely to proteins present in cashew nuts. When someone with this allergy encounters cashews or cashew-containing products, their immune system incorrectly identifies specific cashew proteins as threats. This prompts the release of chemicals like histamines, resulting in allergic manifestations such as hives or respiratory problems.

Are Cashews considered a nut allergy?

Yes, cashews are considered a nut allergy, even though cashews are technically seeds. From an allergy perspective, cashews are typically treated as tree nuts in the context of food allergies. Many people with cashew allergies are also allergic to other tree nuts such as almonds, walnuts, and pistachios.

Therefore, when someone is diagnosed with a cashew allergy, they are often advised to avoid all tree nuts due to the risk of cross-reactivity.

Are cashew allergies common?

Cashew allergies are categorized with nut allergies and affect about 1% of the U.S. population, that is over 3 million people. This number continues to grow as food allergies continue to rise.

According to a Food Allergy Institute, Division of Allergy and Immunology survey, up to half of the participants interviewed have not been evaluated by a doctor for proper diagnosis.

Cashew Allergy Symptoms

The symptoms of a cashew allergy can vary in severity from mild to severe in both children and adults. Common symptoms of a cashew allergy include:

  • Abdominal pain or cramps
  • Cough
  • Diarrhea
  • Eczema or other skin rashes
  • Hives (raised, red welts on the skin)
  • Itching
  • Nausea
  • Rapid or irregular heartbeat
  • Runny or stuffy nose
  • Shortness of breath
  • Sneezing
  • Swelling, particularly around the face, lips, and eyes
  • Vomiting
  • Wheezing

In severe cases, a cashew allergy and its symptoms can lead to anaphylaxis, which is a life-threatening allergic reaction. Symptoms of anaphylaxis include:

  • Difficulty breathing
  • Drop in blood pressure
  • Loss of consciousness
  • Swelling of the throat that can cause a blockage

If you suspect a cashew allergy, it’s crucial to consult with a healthcare professional for proper diagnosis and management.

How long after eating cashews will an allergic reaction occur?

The start of a cashew allergy response differs among individuals. For some, symptoms can surface rapidly, typically within minutes to an hour post-cashew consumption. Conversely, others may experience a delayed onset, with symptoms emerging several hours later, particularly if their allergy is mild. It’s important to note that severe reactions, especially those leading to anaphylaxis, often occur more rapidly.

Complications

A cashew allergy may result in diverse complications, which differ significantly among individuals and can range from mild to severe. Possible complications include:

  • Anaphylaxis: A medical emergency that can lead to a sudden drop in blood pressure, difficulty breathing, and loss of consciousness.
  • Gastrointestinal Problems: Allergic reactions to cashews can result in nausea, vomiting, abdominal pain, and diarrhea, which can contribute to dehydration and other complications.
  • Impact on Quality of Life: This allergy may require significant lifestyle adjustments, including careful food choices, reading labels, and informing others about the allergy.
  • Psychological Impact: Living with a severe food allergy, such as a cashew allergy, can have psychological effects. Individuals may experience anxiety, stress, or fear of accidental exposure, impacting their quality of life.
  • Respiratory Issues: In some cases, a cashew allergy can lead to respiratory symptoms such as wheezing, coughing, and shortness of breath.
  • Secondary Infections: In cases where the skin is broken due to scratching or if there are gastrointestinal symptoms like vomiting and diarrhea, there is a risk of secondary infections.
  • Skin Complications: Skin reactions, including hives, itching, and eczema, are common with cashew allergies. Continuous scratching may lead to skin damage and infections.

Cashew Allergy Causes

3D art showing what food allergy proteins may look like under a microscope.

Cashew allergies, like other food allergies, are caused by an immune system response to specific proteins found in cashew nuts. In the case of cashews, the proteins that commonly trigger allergic reactions include seed storage proteins and allergenic proteins.

Seed Storage Proteins

Cashews, like many other nuts, contain proteins known as seed storage proteins (2S). These proteins can be recognized by the immune system as foreign invaders, leading to an allergic response in susceptible individuals. These proteins play a crucial role in providing a source of energy and nutrients for the developing plant during germination and early growth.

Allergenic Proteins

Certain proteins in cashews have been identified as major allergens. For example, anacardic acid and cardol are compounds found in cashew shells that can cause contact dermatitis. Additionally, proteins such as Ana o 1, Ana o 2, and Ana o 3, have been identified as major allergens in the nut itself.

Cross-Reactive with Cashews

Foods and plants that cross-react with cashews infographic. With a cashew allergy, it is important to know which foods have cross-reactivity, which includes: almonds, hazelnuts, mango, pistachios, poison ivy, poison oak, and sumac.

Cross-reactivity happens when the proteins in one food resemble those in another, causing the immune system to respond to both. For cashews, this can occur with other tree nuts and specific seeds. Foods commonly cross-reactive with cashews include:

  • Almonds
  • Hazelnuts
  • Mango
  • Pistachios
  • Poison Ivy
  • Poison Oak
  • Sumac

It’s important to note that cross-reactivity varies among individuals, and not everyone with a cashew allergy will necessarily react to these cross-reactive foods.

However, for individuals with a known cashew allergy, it is advisable to exercise caution and, when in doubt, consult with a healthcare professional for guidance. Allergists can perform specific tests to identify cross-reactivity and provide personalized advice on dietary restrictions.

Risk Factors

Cashew allergy risk factors are conditions or traits that might heighten the chances of someone developing an allergic reaction to cashews. These factors include:

  • Cross-Reactivity: People who are allergic to other tree nuts, such as almonds or pistachios, may be at a higher risk of cross-reactivity with cashews due to similarities in proteins.
  • Family History of Allergies: Individuals with a family history of allergies may have a higher risk of developing allergies themselves.
  • Geographic Location: The prevalence of food allergies, including cashew allergy, can vary by geographic location.
  • Immune System Factors: Certain immune system characteristics and responses may contribute to the development of allergies. The exact mechanisms are not fully understood.
  • Personal History of Allergies: Individuals with a history of other allergies, such as allergic rhinitis or eczema, may be at an increased risk of developing food allergies.
  • Sensitization to Pollen: Some individuals may experience cross-reactivity between certain tree nuts and pollen allergens. For example, if someone is allergic to birch pollen, they may also be at risk of an allergic reaction to cashews.

It’s important to note that while these factors may increase the risk of developing a cashew allergy, allergies can also occur in individuals without these risk factors. The development of allergies is complex and involves a combination of genetic and environmental factors.

Diagnosis

A cartoon rendering of a doctor working on a laptop computer

Diagnosing a cashew allergy involves a combination of medical history assessment, physical examination, and specific allergy testing. Here are the common methods used for the diagnosis of cashew allergies:

  • Blood Tests: Specific IgE blood tests, such as the ImmunoCAP test, can measure the levels of antibodies (IgE) produced in response to cashew proteins. Elevated IgE levels may indicate sensitization to cashews, but these tests are not always definitive on their own.
  • Elimination Diet and Food Diary: Some healthcare providers may recommend an elimination diet, where cashews are removed from the diet for a period, followed by the gradual reintroduction of cashews while monitoring for symptoms.
  • Medical History: The healthcare provider will take a detailed medical history, including information about any previous allergic reactions, symptoms experienced after eating cashews, and family history of allergies.
  • Oral Food Challenge: This involves the controlled ingestion of cashews to observe any allergic reactions. This is typically done in a medical setting with emergency equipment available in case of a severe reaction.
  • Physical Examination: A physical examination may be conducted to assess any skin reactions (such as hives or eczema) or respiratory symptoms that may be associated with a cashew allergy.
  • Skin Prick Test: Small amounts of cashew allergen extract are applied to the skin, and then the skin is pricked with a tiny needle. If a person is allergic, a small raised bump or hive will typically appear at the test site.

It’s important to consult with a healthcare professional or allergist for proper diagnosis and guidance.

Treatment


The primary treatment for a cashew allergy is strict avoidance of cashews and all cashew-containing products. However, in the event of an accidental exposure or an allergic reaction, there are specific treatment approaches:

  • Allergen Immunotherapy: Allergen immunotherapy, or allergy shots, is a treatment approach where individuals are exposed to small amounts of the allergen over time to build tolerance. While this is more commonly used for respiratory allergies, research is ongoing for its potential application in food allergies.
  • Antihistamines: Over-the-counter or prescription antihistamines can help alleviate mild allergic symptoms such as itching, hives, and sneezing.
  • Corticosteroids: In some cases, healthcare providers may prescribe corticosteroids (such as prednisone) to reduce inflammation and manage more prolonged or severe allergic reactions.
  • Emergency Medical Attention: Even if epinephrine has been administered, individuals experiencing anaphylaxis or severe allergic reactions should seek emergency medical attention immediately.
  • Epinephrine (Adrenaline) Auto-Injector: In cases of severe allergic reactions, such as anaphylaxis, the immediate administration of epinephrine via an auto-injector (e.g., EpiPen) is the first-line treatment.

Individuals with cashew allergies need to work closely with healthcare professionals, including allergists, to develop a personalized management plan.

Prevention

Two women sitting on bean bag chairs as friends, they look to be talking to each other and sharing stories.

Preventing allergic reactions to cashews involves strict avoidance of cashews and cashew-containing products. Here are some key strategies to prevent cashew allergic reactions:

  • Avoid Cross-Contact: Be cautious about cross-contamination, which occurs when allergens from one food come into contact with another. This can happen in shared kitchen utensils, cooking surfaces, or through air particles.
  • Avoid Foods with Cross-Reactivity: Individuals with a cashew allergy should be aware of cross-reactivity with other tree nuts, such as pistachios and almonds, and potentially related foods, like mangoes.
  • Educate Caregivers and Teachers: If the person with a cashew allergy is a child, it’s crucial to educate caregivers, teachers, and school staff about the allergy. Provide clear instructions on what to avoid and the steps to take in case of an allergic reaction.
  • Inform Others: Make sure to inform restaurant staff, friends, family, and caregivers about the cashew allergy. When dining out, ask about the ingredients used in dishes, and inform kitchen staff about the allergy to prevent cross-contamination.
  • Read Food Labels: Individuals with cashew allergies should carefully read food labels to identify any potential sources of cashews. Food manufacturers are required to list common allergens, including tree nuts, on their labels.
  • Wear Medical Alert Identification: Wearing a medical alert bracelet or necklace that specifies the cashew allergy can be helpful in case of emergencies. This provides quick and clear information to first responders and healthcare professionals.

Summary


A cashew allergy occurs when the immune system reacts to proteins in cashews, causing a range of symptoms from mild to severe. It’s often treated like a tree nut allergy due to similarities. Symptoms can vary widely and may appear quickly or several hours after consumption. Be careful of cross-contamination and cross-reactivity. For proper management, seek proper medical advice.

What is your cashew allergy story? Please feel free to reach out with any questions via email, chris@allergypreventions.com.