It starts one day at snack time: your child refuses to finish eating a big, juicy apple, complaining about a tingling and itchy feeling in the lips, tongue and throat. That’s strange, you think – apples have always been a favourite food. And over the next little while, you notice that discomfort occurs when eating different types of raw fruits, vegetables and nuts. The symptoms are mild, but obviously uncomfortable, and they only seem to last about 20 minutes after eating the offending food. A diagnosis from an allergy specialist may confirm that your child has Oral Allergy Syndrome (OAS).
OAS is actually a cross-reaction triggered by pollen-producing plants: trees, grass, weeds, and other flowering plants. Patients with OAS react to similar proteins found in both the raw foods and the plants, says Dr. Karen McInnis, of the Calgary Allergy Clinic. “It’s called ‘oral’ because the symptoms occur in the mouth.”
Up to one-third of all people who suffer from seasonal allergies also have OAS – in Canada, that’s nearly 10 percent of the entire population. OAS is usually not a life-threatening condition, although in some severe cases, it may lead to anaphylaxis or other dangerous reactions.
|Allergies to this type of pollen…
||… May also trigger an allergic reaction to these foods
|Birch||Fruits: apple, apricot, cherry, kiwi, nectarine, peach, pear, plum, prune
Vegetables: anise, beans, caraway, carrot, celery, coriander, cumin, dill, fennel, green pepper, lentils, parsley, parsnips, peanut, peas, potato, tomato
Nuts: almond, hazelnut, walnut
|Grass||Fruits: kiwi, melon, orange, tomato, watermelon|
|Mugwort||Fruits: apple, melon, watermelon
Vegetables: carrot, celery
|Ragweed||Fruits: banana, cantaloupe, honeydew, watermelon
Vegetables: cucumber, zucchini
The symptoms of OAS usually first occur in preteens and teenagers, although Dr. McInnis has seen it in patients as young as seven or eight years old. Fortunately, there are a few things you can do to minimize your child’s risk of developing OAS.
Controlling seasonal allergies
OAS and hay fever are inextricably linked, so the key is to control seasonal allergies at all stages in your little one’s life:
- Monitor the daily pollen counts on your local weather channel. Pollen counts are heaviest during the morning and early evening, so if you’re planning a trip to the playground, go in the afternoon.
- Don’t hang clothes out to dry during times of high pollen count or on a windy day.
- Close the windows in your house or car when the pollen counts are high.
- Choose female plants only (male plants are responsible for pollen production) and stay away from plants with fragrant blossoms.
- Mow the lawn in the late afternoon. Or consider replacing the lawn with decorative stone mulch and low-pollen plants.
- Keep your children off the lawn for at least 48 hours after the application of chemical lawn sprays or avoid using them altogether.
- Keep your garden and lawn in tip-top condition. Plants actually produce more pollen when they are stressed by their environment.
- Don’t display fresh or dried flowers inside the house.
Minimizing the effects of food triggers
- Dr. Karen McInnis, a Calgary allergist, recommends cooking offending foods instead of eating them raw. Nuts are an exception: cooking, baking or roasting will not prevent a reaction.
- If your child really likes a trigger food, chase it with a glass of water and a slice of bread. The bread will help diminish uncomfortable symptoms. But bear in mind that there is always a slight risk of a more severe reaction.
- Peel all fruits and vegetables. Sprinkle raw fruit with lemon juice before serving – this may minimize a reaction.
- Consult your child’s physician and an allergist to determine treatment with antihistamines or immunotherapy, or consider naturopathic treatments with a professional practitioner.
Originally published in ParentsCanada magazine, October 2012.