Oral Allergy Syndrome Australia: Causes, Symptoms, and Treatments

Oral allergy syndrome is a reaction to certain foods, usually raw, that is localised to the mouth and throat.

If you have OAS, then you might find that your mouth, throat, and tongue tingles after you’ve eaten particular foods, but what you might not know is that this reaction is related to pollen allergies.

Particular fruits and vegetables elicit reactions depending on what kind of pollen you react to, and your reactions to these foods can even worsen during seasons of high pollen activity.

The good news is that OAS is highly manageable, and rarely life-threatening.

That being said, it’s still important to know how allergy oral syndrome functions, getting a comprehensive allergy test for a diagnosis, and what an effective treatment plan might look like.

What is oral syndrome food allergy?

Oral allergy syndrome is an allergic reaction to certain raw foods (fruits, vegetables, and nuts) that is limited to the mouth, tongue, and throat.

Swelling and tingling in the mouth is always alarming, but this particular kind of allergy is usually localised, and is rarely associated with anaphylaxis.

In fact, less than 2% of people experience oral allergy syndrome anaphylaxis.

The allergy is localised because, while your immune system mistakes the foods for an attack, your stomach acid breaks down the ‘harmful’ proteins before the immune response can spread any further.

Cooking or peeling the food often removes the problem proteins, which is why many people with oral allergy syndrome can safely eat the same foods when they’re cooked.

Causes of oral allergy syndrome

Oral allergy syndrome works in a very specific way, and reactions to certain foods are related to specific pollen allergies.

This is because the immune system identifies similar proteins in both pollen and certain raw fruits, vegetables, and nuts, and launches an immune response to cope with what it deems as a threat.

Symptoms often appear within minutes of eating raw versions of these foods and usually go away quickly, even without treatment.

For this reason, oral allergy syndrome is sometimes also called Pollen Food Allergy Syndrome, or PFAS.

Oral allergy syndrome is often worse during pollen seasons, as the immune system is working in overdrive.

Oral allergy syndrome chart

Here’s how common pollen allergies relate to food triggers:

Pollen Allergy	Oral Allergy Syndrome Foods
Birch pollen	Aniseed, caraway, coriander, fennel, parsley, peanuts, soybeans, avocados, apples, pears, cherries, kiwis, apricots, peaches, plums, carrots, celery, hazelnuts, almonds
Grass pollen	Melons, potatoes, Swiss chard, tomatoes, oranges, celery
Ragweed pollen	Artichokes, melons, bananas, cucumbers, zucchini, chamomile
Mugwort pollen	Celery, garlic, mustard, aniseed, caraway, parsnip, onions, cabbage, carrot, parsley, coriander, pepper, sunflower seeds

Common symptoms of oral allergy syndrome

If you have OAS, you might experience some of the following symptoms when eating trigger foods:

• Itchy or tingling sensation in the mouth, lips, tongue, or throat
• Mild swelling of the lips, tongue, or throat
• Redness or irritation inside the mouth
• Scratchy or sore throat
• Mild swelling or itching around the roof of the mouth or gums
• Occasionally, mild difficulty swallowing

Diagnosing oral allergy syndrome

Because the symptoms of oral allergy syndrome come on quickly, it can be fairly straightforward to diagnose.

You may notice a swelling or tingling in the mouth soon after eating one of the trigger foods.

If this is happening to you, then you should start by speaking to your GP, or to an allergy specialist.

Your allergist will take a detailed history, asking about your symptoms, the specific foods that trigger a reaction, and whether you also experience seasonal hay fever.

In some cases, skin prick testing or blood tests may be used to check for related pollen allergies, which can help confirm the connection.

Food challenges (in which you eat a small amount of a suspected trigger under medical supervision) may also be used in certain situations, though this isn’t always necessary

Treatment and management of oral allergy syndrome

As far as allergies go, oral allergy syndrome is one of the easiest to manage.

You can usually mitigate the impact on your life by avoiding trigger foods, or by cooking the foods thoroughly.

Oral allergy syndrome is rarely life-threatening, but anything that causes swelling should still be closely monitored.

You can further manage your OAS by:

• Avoiding Trigger Foods: The most effective way to prevent symptoms is to avoid eating raw fruits, vegetables, or nuts that cause your reaction. Cooking these foods alters the shape of the allergenic molecule. However not all allergenic proteins are susceptible to this. This is why it is important to see a doctor. You can also make a point to temporarily remove trigger foods during pollen season, as you’re more likely to have a reaction at this time of year.
• Antihistamines: Over-the-counter antihistamines can help reduce itching, swelling, and other mild symptoms if you accidentally eat a trigger food.
• Oral Allergy Desensitisation: Allergy specialists may recommend immunotherapy to help reduce your sensitivity over time.
• Emergency Plan: Although rare, if you have severe reactions or difficulty breathing, carry an epinephrine auto-injector (EpiPen) and seek emergency care immediately. Unfortunately, there is no cut-and-dried ‘cure’ for OAS, but many people find that their
  symptoms improve over time.

How Allergy Testing can help

At Allergy Testing, we specialise in identifying the causes of your allergy symptoms so you can live more confidently.

Whether you’re struggling with hayfever, food sensitivities, skin reactions, or unexplained respiratory issues, our expert team uses the latest testing methods to pinpoint your triggers accurately.

If you suspect that you have oral allergy syndrome, Allergy Testing can help you identify your trigger foods, explain the relationship to pollen allergies, and come up with a treatment plan to help you better manage your symptoms.

Book your appointment with Allergy Testing today