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Top 4 Common Pollen Food Allergy Syndrome (PFAS) Triggers

Written by Andrew Le, MD

UpdatedFebruary 22, 2024

Pollen Food Allergy Syndrome (PFAS) is a common condition affecting a significant portion of the global population, estimated anywhere from 2% to as high as 70%. This occurs when the body confuses certain proteins in pollen with those in specific foods, triggering various symptoms.

PFAS can be particularly frustrating and uncomfortable, causing itching and digestive discomfort when consuming certain foods like raw foods and nuts during high pollen seasons. This syndrome disrupts daily life and may lead to unnecessary dietary restrictions, impacting quality of life.

In this article, you will learn about PFAS syndrome and its symptoms, explore the common triggers of pollen-food allergy, understand diagnosis and treatment options, and receive practical preventions for managing this allergy.

🔑 Key Takeaways

  • PFAS is a widespread condition, impacting a substantial part of the world's population, with estimates ranging from 2% to 70%.
  • PFAS primarily affects individuals already sensitized to pollen allergens like tree, grass, or weed pollen. It's prevalent in people with hay fever or other pollen allergies, emphasizing the link between environmental pollen and food allergies.
  • Research indicates that PFAS tends to be more prevalent in adults and teenagers, with rates ranging from 13% to 53.8%, while it's less common in young children, where prevalence ranges from 4.7% to over 20%.
  • Specific foods can trigger PFAS in individuals with pollen allergies. For example, grass pollen allergies can extend to fruits and vegetables like cantaloupe, honeydew, oranges, tomatoes, and white potatoes.
  • Diagnosing PFAS involves a clinical evaluation by an allergist. Skin prick testing may be performed to confirm the presence of PFAS. Thistest helps identify patterns of allergic reactions related to pollen exposure and specific foods.
  • Treatment for PFAS includes antihistamines for milder symptoms and epinephrine for severe allergic reactions. Being aware of these treatment options is essential for individuals living with PFAS.
  • To manage PFAS, avoiding foods that trigger the condition is crucial. Additionally, taking steps to minimize pollen exposure, such as avoiding outdoor activities during high pollen seasons, can help prevent allergic reactions.
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Understanding Pollen Food Allergy Syndrome

PFAS, also known as oral allergy syndrome or OAS is a food allergy that occurs in individuals already sensitized to pollen allergens, such as tree, grass, or weed pollen.

According to research, PFAS tends to be more prevalent in adults, with a range of 13% to 53.8%, and teenagers, while it is less common in young children, where prevalence ranges from 4.7% to over 20%. Those at risk should be aware of their condition and potential food triggers to minimize discomfort and ensure effective management.

PFAS is characterized by allergic reactions to certain fruits, vegetables, and nuts, which are cross-reactive with the pollen allergens the individual is sensitive to.

However, not all individuals with pollen allergies will develop PFAS, as its occurrence depends on the specific proteins found in the pollen they are allergic to and the foods they consume.

Pollen Food Allergy Syndrome Symptoms

PFAS is often perceived as a low-risk condition, affecting up to 3% of patients who may exhibit systemic symptoms without oral manifestations. These symptoms typically last briefly, ranging from a few minutes to half an hour.

While systemic reactions are seen in 2-10% of PFAS cases, it's crucial to recognize that PFAS can also manifest with a range of distinct and diverse symptoms, including:

  • Oral-pharyngeal pruritus: The most prevalent symptom is itching in the mouth and throat.
  • Throat Tightness: Patients may experience a sensation of constriction or tightness in the throat.
  • Difficulty Swallowing: Some individuals may find it challenging to swallow food.
  • Nausea: A feeling of sickness or an upset stomach.
  • Dysphonia: Changes in voice quality or difficulty speaking.
  • Nasal Itching: Itching in the nasal passages.
  • Ear Itching: Itching in the ear canals.

During an acute episode of PFAS, a physical examination may reveal distinct features, such as:

  • Angioedema: Swelling of the tongue, uvula, lips, face, and area around the eyes.
  • Perioral urticarial eruptions: The symptoms are characterized by itchy, raised, red welts or hives that develop around the mouth and resemble a rash.

These symptoms typically remain localized to the mouth and throat. However, some individuals may experience more severe or systemic features, including:

  • Urticaria and Dyspnea: Characterized by hives and difficulty breathing.
  • Anaphylactic Shock: Anaphylactic shock, a life-threatening allergic reaction involving multiple organ systems, can occur in about 1.7% of PFAS individuals, leading to a rapid drop in blood pressure, breathing difficulties, and systemic symptoms.

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Top 4 Common Pollen-Food Allergy Triggers

Common pollen-food allergies often arise when the body's immune system mistakenly identifies proteins in certain foods similar to those found in pollen. These mistaken identities can lead to allergic reactions in susceptible individuals. Here are the four common pollen-food allergy triggers:

1. Birch Pollen

Birch pollen allergies are common, affecting 50% to 90% of birch-allergic patients. When exposed to birch pollen, individuals may experience adverse reactions to various fruits and vegetables, including:

  • Apples
  • Pears
  • Cherries
  • Apricots
  • Carrots

2. Ragweed Pollen

Approximately 50 million people in the US suffer from allergies triggered by ragweed pollen. This type of pollen allergy can lead to reactions when consuming a range of fruits and vegetables, such as:

  • Bananas
  • Cantaloupe
  • Cucumbers
  • Honeydew
  • Watermelon
  • White potatoes
  • Zucchini
  • Sunflower seeds

3. Grass Pollen

Grass pollen allergies affect a significant portion of the population, impacting around 10% to 30% of children and adults in the US. Reactions to grass pollen can also extend to certain fruits and vegetables, including:

  • Cantaloupe
  • Honeydew
  • Oranges
  • Tomatoes
  • Watermelon
  • White potatoes

4. Mugwort Pollen

Mugwort pollen is a potent allergen, and over 95% of individuals allergic to it are sensitized to it. Consuming certain foods with mugwort pollen can trigger PFAS. Some of these foods include:

  • Celery
  • Fennel
  • Carrots
  • Parsley
  • Garlic
  • Cabbage
  • Broccoli
  • Coriander
  • Cumin
  • Peaches
  • Lychee
  • Mangos
  • Grapes
  • Sunflower seeds
  • Peanuts

Diagnosis and Testing For Pollen Food Allergy Syndrome

The initial step in diagnosing PFAS involves a thorough clinical evaluation. Diagnosis and testing for PFAS typically involves a combination of medical history, physical examination, and allergy tests. Here's how it's done:

1. Skin Prick Testing

Skin prick testing is a common diagnostic method for PFAS. In this test, a small amount of allergen extract from the suspected food, like apple or birch tree pollen, is applied to the skin, usually on the forearm or back. A tiny needle is then used to prick or scratch the skin, allowing the allergen to penetrate below the surface.

Suppose the individual is allergic to the food in question. In that case, they typically develop a localized allergic reaction, resulting in a raised, itchy, or red bump at the test site. This test helps pinpoint the specific foods that trigger allergic reactions in people with PFAS.

2. Serum IgE Antibody Measurements

Blood tests can be conducted to measure the levels of specific immunoglobulin E (IgE) antibodies to allergens in the bloodstream. These tests can identify whether an individual has elevated IgE levels in response to particular food or pollen allergens.

Elevated IgE levels, especially when specific to certain foods and pollens, can suggest the presence of PFAS.

3. Oral Food Challenge Test

Sometimes, when skin prick testing or serum IgE measurements are inconclusive, or it's important to confirm the diagnosis, an oral food challenge test may be conducted. This test involves supervised consumption of the suspected allergenic food under medical supervision.

This test is considered the gold standard for diagnosing food allergies, including PFAS. Still, it should only be performed by trained healthcare professionals in a controlled medical setting due to the risk of severe allergic reactions.

Pollen Food Allergy Syndrome Treatment

Suppose you experience PFAS reactions after consuming certain foods. In that case, it is recommended to discontinue consumption of the offending food as the symptoms typically subside within 30 minutes.

However, medical intervention may be necessary if the symptoms are severe or persistent. Your healthcare provider may recommend or prescribe medications to manage your PFAS symptoms. These medications can include:


Antihistamines are a common medication used to counteract the effects of PFAS by blocking the release of histamines, which are responsible for causing mild allergic reactions. Antihistamines are available over-the-counter and include widely known brands such as:

  • Diphenhydramine (Benadryl®)
  • Fexofenadine (Allegra®)
  • Loratadine (Claritin®)


In cases of severe allergic reactions triggered by PFAS, epinephrine is a life-saving medication that can be administered through self-injection. It rapidly reduces swelling and opens airways, allowing for easier breathing. Allergists typically prescribe epinephrine, which is available in the form of auto-injectors, such as:

  • Auvi-Q®
  • EpiPen®

🗒️ Related Articles

Allergy attacks happen when you encounter something your body sees as a threat, an allergen. This triggers your immune system, causing symptoms like sneezing, itchy eyes, hives, swelling, and sometimes breathing difficulties. If you want to learn more about allergies. You can check out some of our articles:

Prevention Of Pollen Food Allergy Syndrome

To mitigate the risk of experiencing PFAS, avoiding consuming foods that trigger the condition is essential. Additionally, there are various strategies to prevent or minimize reactions to trigger foods:

  • Identify Your Allergies: The first step in preventing pollen food allergy syndrome is determining which pollens trigger your allergies. An allergist can perform skin or blood tests to identify your allergens.
  • Avoid Trigger Foods: Once you know which foods will likely cause reactions due to cross-reactivity, you can avoid them during high pollen seasons. Keep a list of trigger foods and consult it before eating, especially during peak pollen periods.
  • Cooking and Processing: Cooking or heat-processing certain foods can often break down the allergenic proteins responsible for cross-reactivity. For example, lightly cooking fruits or vegetables may make them less likely to trigger a reaction.
  • Peel or Remove Skin: Sometimes, peeling fruits and vegetables or removing the skin can reduce the likelihood of a reaction since the proteins causing the cross-reactivity are often found in the skin.
  • Freeze or Can Foods: Freezing or canning fruits and vegetables can also reduce the risk of cross-reactivity, as it can alter the proteins responsible for allergic reactions.
  • Avoid Raw Foods: If you're particularly sensitive, consider avoiding raw fruits and vegetables that cross-react with pollen. Opt for cooked or processed alternatives instead.


Managing PFAS requires a comprehensive understanding of the common triggers, such as birch and mugwort pollen, which can lead to allergic reactions when consuming specific fruits, vegetables, or nuts. Diagnosis involves clinical evaluation, skin prick tests, IgE antibody measurements, and, in some cases, oral food challenges.

While there is no cure for PFAS, treatment options include antihistamines and epinephrine for severe reactions. Preventative measures involve avoiding trigger foods, cooking them to reduce allergenic proteins, considering seasonal factors, and exploring allergy immunotherapy.

By comprehensively understanding PFAS, individuals can better navigate and manage this intricate pollen-food allergy syndrome, improving their quality of life and overall health.

FAQs On Pollen-Food Allergy

Is it safe for me to consume honey if I have a pollen allergy?

Some individuals with a severe pollen allergy may experience a potentially life-threatening allergic reaction called anaphylaxis when they consume honey. This reaction can lead to severe breathing difficulties, while others might encounter milder allergic responses like itching or swelling in the mouth, throat, or skin.

What measures can be taken to alleviate pollen allergies?

Stay indoors on dry, windy days. Opt for outdoor activities after rainfall, as it helps clear pollen from the air. Avoid lawn mowing, weeding, and other gardening activities that can agitate allergens. Change out of clothes worn outside and shower to rinse pollen from your skin and hair.

What are the consequences of untreated pollen allergies?

Neglected allergies can worsen over time, resulting in more severe allergy episodes. Frequent or extended allergic reactions may also compromise your immune system and make you susceptible to potential complications like bacterial or fungal infections in the sinuses, lungs, ears, or skin.

What should I do if I suspect a pollen-food allergy?

If you suspect a pollen-food allergy, seek medical advice from an allergist. They can diagnose accurately, recommend appropriate management strategies, and help you understand your triggers.

What is pollen-food allergy syndrome in children?

The symptoms of pollen-food allergy syndrome in kids typically involve a rash or itching sensation around the lips. However, it can also lead to systemic symptoms like a widespread rash, breathing difficulties, coughing, wheezing, vomiting, abdominal pain, low blood pressure, paleness, headache, and dizziness.

Illustration of a healthcare provider asking questions on a smart phone.
Allergy treatment - Online visit
Get virtual care from a licensed clinician—no appointment needed
Illustration of a healthcare provider asking questions on a smart phone.
  • $29 one-time assessment
  • No video call or appointment necessary
  • Personalized treatment plan prescribed for your condition