Oral allergy syndrome

Oral allergy syndrome is common in people with asthma or allergic rhinitis (hay fever) who are sensitive to pollens.

These pollens have proteins that are similar to those found in some raw fruit, vegetables and nuts.

Your immune system can confuse these proteins for pollen. This leads to an allergic reaction.

Oral allergy syndrome affects your mouth, lips, tongue and throat. It can cause:

• tingling
• itching
• redness
• swelling.

It normally happens 5 to 10 minutes after eating. These symptoms are usually mild and go away within an hour.

Oral allergy syndrome rarely progresses to anaphylaxis.

Foods that most commonly cause symptoms are:

• fruits such as apples, apricots, cherries, kiwifruit, nectarines, peaches and plums
• vegetables such as cabbage, carrot, celery, green capsicum, potato and tomato
• raw nuts and seeds such as almonds, hazelnuts, peanuts, sunflower seeds and walnuts
• fresh herbs such as coriander, dill and parsley.

Most people only react to a few of these foods.

If you think you have oral allergy syndrome, talk to your healthcare provider or dietitian. The symptoms are usually enough to diagnose it, but you may need a test, such as a skin prick test.

• Avoid the foods that cause you symptoms in their raw, uncooked form.
• Try drinking water to rinse your mouth out if your symptoms are mild. If symptoms persist, take an antihistamine.
• Try canned or cooked versions of the fruits, vegetables and nuts you react to. Most people with oral allergy syndrome can tolerate these, as heating destroys the allergy-causing proteins.
• Try peeled vegetables or fruit, as the allergy-causing proteins are often found in the skin.
• Be careful with fresh smoothies and raw juices — especially if you are not clear on all the ingredients.

See your healthcare provider if you:

• react to multiple plant foods
• have symptoms with canned or cooked vegetables or fruit
• have severe symptoms after eating nuts, such as difficulty breathing, wheezing, hives or significant swelling.