Allergy testing puzzle: A person surrounded by allergens with a puzzle piece above, representing the complexities of allergy diagnosis.

Decoding Your Allergy Test: What Profilin Sensitivity Really Means

Mira Elwood in Health & Wellness December 2025 • 4 min read.

"Understanding profilin in allergy testing: Why a positive result doesn't always mean what you think it does, and how to navigate the complexities of cross-reactivity."

If you've ever undergone allergy testing, you might have encountered the term "profilin." Profilins are proteins found in pollen, plant-based foods, and even latex. They're known as panallergens, meaning they're present in many different sources and can trigger allergic reactions in sensitized individuals. But here's where it gets tricky: a positive allergy test for profilin doesn't always tell the whole story.

The initial allergic response to profilin is usually triggered by the inhalation of pollen, leading to common allergic reactions like allergic rhinitis (hay fever) and oral allergy syndrome (OAS), where you experience itching or swelling in your mouth after eating certain raw fruits or vegetables. It's logical to assume that if you're allergic to profilin, you'll react to all foods and pollens containing it. However, cross-reactivity – where your body recognizes similar proteins from different sources – isn't always complete.

A recent study investigated the prevalence of profilin sensitivity and examined the correlation between profilin allergy and reactions to various pollens and plant-based foods. The researchers discovered that while many individuals were sensitized to profilin, there wasn't a strong link between a positive profilin test and positive tests for specific pollens and foods known to contain profilin. This begs the question: Why isn't a profilin allergy always reflected in reactions to these sources?

The Profilin Puzzle: Why Standard Allergy Tests Can Be Misleading

Allergy testing puzzle: A person surrounded by allergens with a puzzle piece above, representing the complexities of allergy diagnosis.

The key to understanding this lies in the nature of allergy testing itself. Standard skin prick tests (SPT) use extracts from pollens and foods. The study highlights that the presence of profilin in the raw source material doesn't guarantee it's present in the commercial SPT extracts used by allergists. This is because the extraction process can affect the protein composition, potentially removing or altering the profilin.

To investigate this further, the researchers used a technique called SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) to analyze the protein content of various commercial SPT extracts. This method separates proteins based on their molecular weight, allowing researchers to see if profilin was actually present in the extracts.

The Method: Commercial SPT extracts of various substances were tested with SDS-PAGE. Included purified palm date profilin, peach (whole, pulp, and peel extracts), hazelnut, Olea europea, Parietaria judaica, and Phleum pratense.
The Outcome: Profilin was detected in most extracts EXCEPT peach extracts; it wasn't in the whole peach extract or in the extracts of peel or pulp.

The results were revealing. While profilin was detected in extracts from hazelnut, Phleum pratense (Timothy grass), and Parietaria judaica (pellitory), it was notably absent in peach extracts. This is significant because peaches are known to contain a profilin called Pru p 4. The absence of Pru p 4 in the peach extracts explains why someone might react to fresh peaches but not test positive on a standard peach allergy test.

The Takeaway: Personalized Allergy Testing for Accurate Results

So, what does this mean for you? If you suspect you have a profilin allergy but your allergy tests are inconclusive, it's crucial to discuss your concerns with your allergist. Using a purified profilin extract for skin prick testing can provide a more accurate assessment of your profilin sensitivity. Furthermore, remember that allergy testing is just one piece of the puzzle. Your allergist will also consider your medical history, symptoms, and potential cross-reactivities to develop a personalized management plan to keep your allergies under control.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.aller.2018.05.003, Alternate LINK

Title: Detection Of Profilin In Spt Extracts That Are Supposed To Contain It

Subject: General Medicine

Journal: Allergologia et Immunopathologia

Publisher: Codon Publications

Authors: C. Pitsios, A. Iliopoulou, M. Kontogianni, G. Papagregoriou

Published: 2019-01-01

Everything You Need To Know

What exactly is profilin, and why is it relevant to allergy testing?

Profilin is a type of protein known as a panallergen, found in various sources such as pollen, plant-based foods, and even latex. It's significant in allergy testing because it can trigger allergic reactions in sensitized individuals. However, a positive allergy test for profilin doesn't always provide a complete picture of all potential allergic reactions due to cross-reactivity and variations in testing methods.

If I test positive for profilin, does that automatically mean I'm allergic to all foods and pollens containing it?

Not necessarily. While profilin is present in many foods and pollens, cross-reactivity isn't always complete. This means that your body might recognize similar proteins from different sources, but the reaction may not be consistent across all of them. A positive profilin test indicates sensitivity but doesn't guarantee a reaction to every source containing profilin.

Why might a standard allergy test not accurately reflect my reaction to foods like peaches, even if they contain profilin?

Standard skin prick tests (SPT) use extracts from pollens and foods. The presence of profilin, such as Pru p 4 in peaches, in the raw source material doesn't guarantee its presence in the commercial SPT extracts. The extraction process can affect the protein composition, potentially removing or altering the profilin. For example, a study using SDS-PAGE found that profilin was absent in peach extracts, even though peaches are known to contain it. This could explain why someone reacts to fresh peaches but not to a standard peach allergy test.

What is SDS-PAGE, and how does it help in understanding profilin allergies?

SDS-PAGE, or sodium dodecyl sulfate polyacrylamide gel electrophoresis, is a technique used to analyze the protein content of various substances. It separates proteins based on their molecular weight, allowing researchers to see if profilin is actually present in commercial SPT extracts. By using SDS-PAGE, researchers can determine whether the absence of a reaction in a standard allergy test is due to the absence of profilin in the extract itself, rather than the absence of an allergy to the source material, helping to explain misleading test results.

If standard allergy tests for profilin are sometimes misleading, what steps can I take to get a more accurate assessment of my allergies?

Discuss your concerns with your allergist. Request testing using a purified profilin extract for skin prick testing, as this can provide a more accurate assessment of your profilin sensitivity. Your allergist should also consider your medical history, symptoms, and potential cross-reactivities to develop a personalized management plan. Understanding the limitations of standard allergy tests and exploring more specific testing methods are crucial for effective allergy management.