Foods That May Worsen Pollen Allergies By Neil Osterweil

What do yet get when you cross a cantaloupe with a ragweed plant, or an apple with a birch tree? An itchy mouth.

For many people with hay fever, eating cantaloupe can cause itching or hives in their mouths. Eating uncooked apples may do the same to people with birch pollen allergy.
 
They have oral allergy syndrome. So do up to a third of pollen allergy patients, notes the American Academy of Allergy, Asthma, & Immunology (AAAAI).
 
Most cases are mild. But some can be an early warning sign of a serious or even life-threatening allergic reaction called anaphylaxis.
 
Oral Allergy Syndrome: What Happens
 
You can blame oral allergy syndrome on the immune system trying a little too hard to protect the body.

In hay fever (seasonal allergies), the immune system treats certain inhaled pollen proteins as foreign invaders. It prompts sneezing, runny nose, watery or itchy eyes, and other unpleasant symptoms to flush the intruder out of the body.

In oral allergy syndrome, the immune system treats proteins similar to those in pollen that are sometimes found in fruits or vegetables the same way. It's as if it says, “Close enough!” and attacks it. That's called cross-reactivity.

Foods to Watch Out For

Here are foods that may have proteins that cross-react with pollen proteins:

Ragweed Allergy: “Ragweed, in theory, cross-reacts with bananas and melons, so people with ragweed allergies may react to honeydew, cantaloupe, and watermelons, or tomatoes,” says Warren V. Filley MD, from the Oklahoma Allergy & Asthma Clinic in Oklahoma City.

Zucchini, sunflower seeds, dandelions, chamomile tea, and echinacea also go on that list, notes the AAAAI's web site.

Birch Pollen Allergy: People with birch pollen allergies may react to kiwi, apples, pears, peaches, kiwi, plums, coriander, fennel, parsley, celery, cherries, carrots, hazelnuts, and almonds.

Grass Allergy: People with grass allergy may react to "peaches, celery, tomatoes, melons, and oranges," the AAAAI states.

Latex Rubber Allergy: Like pollen allergy, people allergic to latex rubber may react to "bananas, avocados, kiwi, chestnut, and papaya," the AAAAI states.
 
Hannelore A. Brucker, MD, of the Southdale Allergy & Asthma Clinic in Minneapolis, often asks her allergy patients about possible oral symptoms.
 
“I ask if they have itching in the mouth when they eat apple, and if they say 'No' and then I see a skin test and it’s high-positive for birch, I ask again,” Brucker tells WebMD.

Oral sensitivity tends to develop over time, with repeated exposures to inhaled pollens. Brucker says most of her patients with oral allergy syndrome are in their 20s and 30s.

Filley's advice: See a board-certified allergist. "It could be oral allergy or could be something more serious," Filley says.

You may get a skin-prick test. A bit of the suspected trigger goes on a light scratch on your back or forearm. If that spot turns red or swells in about 15 minutes, it's an allergic reaction.

Next, the doctor has to analyze the problem. Either this is mainly oral allergy and not to worry, or this could be more serious and [you need to] take more precautions, such as carry epinephrine with you," Filley says.

A recent study shows that in about 2% of patients with oral allergy syndrome, oral allergy symptoms could progress to anaphylactic shock, a serious reaction that could be deadly without immediate treatment such as an epinephrine shot.

Treating by Not Eating Trigger Foods

The basic rule: If a food makes you uncomfortable, don’t eat it!

Cooking may help. It often breaks down or alters the trigger proteins so that the immune system doesn't target them.

Peeling fruits such as apples may also help some people, because most trigger proteins are in the peel. Canning also breaks down those proteins, so canned fruit may be an option.
 
SOURCES:
 
Hannelore A. Brucker, MD, Southdale Allergy & Asthma Clinic, Minneapolis.

Warren V. Filley, MD, Oklahoma Allergy & Asthma Clinic, Oklahoma City.

National Institute of Allergy and Infectious Diseases.

American Academy of Allergy, Asthma & Immunology.

Webber. C.. The Annals of Allergy, Asthma and Immunology, February 2010; vol 104: pp 101-182.