Why some people get wheezy when peeling potatoes

by Jennifer Bowden / 16 October, 2017
RelatedArticlesModule - Oral allergy syndrome

Photo/Getty Images

As if living with hay fever isn’t enough, many people with oral allergy syndrome also react to certain foods. 

QUESTIONI become wheezy when peeling potatoes and get a tingly mouth when I eat alfalfa sprouts and macadamia nuts. Earlier this year, I ate a handful of uncooked mung beans and I practically lost my voice. At Auckland City Hospital, I was given adrenaline to overcome this, and I now carry an adrenaline pen. My reaction has been called an oral allergy. What are fresh products sprayed with to cause this? I’m now careful about washing and peeling fresh vegetables.

ANSWEROral allergy syndrome (OAS) affects about three-quarters of hay-fever sufferers, says allergy specialist Dr Vincent St Aubyn Crump.

Crump, the author of Allergies: New Zealand’s Growing Epidemic, says the syndrome is prevalent in regions such as Queenstown and Gisborne. The symptoms of this secondary allergy are often mild, so many people are unaware they have it and habitually avoid foods that they react to.

Certain fruit, vegetables, nuts and seeds contain proteins with a similar structure to pollens. The immune system of hay-fever sufferers can confuse the two and start reacting to certain food proteins, says Crump, a consultant allergist at University Hospital of South Manchester. “It’s mainly due to a cross-reaction with birch pollen, but it’s also seen with grass and weed pollen cross-reactions.”

Unlike a primary allergy, such as that triggered by peanuts, which can lead to life-threatening anaphylaxis, OAS is usually localised. “The reason is that these allergens are labile and easily destroyed by the digestive enzymes in the gut.” So after causing symptoms such as swelling of the lips and/or itching or mild swelling inside the mouth or throat, the proteins are destroyed by the digestive system rather than being absorbed into the circulation as allergens.

Dr Vincent St Aubyn Crump.

Some people with the syndrome report nose and eye symptoms and itchy hands when handling raw potatoes or parsnips. So combined with the fact that it rarely causes anaphylaxis, or a severe reaction, “oral allergy syndrome” is a bit of a misnomer, Crump says. “Pollen food syndrome is a better term.”

Common triggers are raw fruit and vegetables, including apples, apricots, pears, cherries, kiwifruit, mango, plums, peaches, nectarines, tomatoes, carrots and celery. Other plant foods occasionally cause the condition, including raw peas, soy milk, and raw or stir-fried legumes such as bean sprouts.

Cooking can destroy the allergic effect of trigger foods. “Apples are one of the most common causes. However, people who get OAS from apples can eat them stewed without any symptoms.”

But in a small number of people, the syndrome causes a serious anaphylactic reaction. Typically, nuts are the trigger, says Crump. “The nuts commonly associated with pollen food syndrome are hazelnuts, almonds and walnuts. Again, it’s usually raw nuts that cause symptoms, whereas processed nuts, such as in chocolate spread Nutella, are tolerated.”

It’s important to distinguish primary nut allergies unrelated to pollen from OAS caused by nuts, he says. “If there is doubt, affected people should be assessed by an allergist, as occasionally an adrenaline auto-injector is needed.”

For those with OAS, the solution is cooking fresh produce to destroy the allergens. Offending fruit should be stewed. “Even a microwave will do it,” says Crump. Similarly, trigger vegetables should be cooked.

People who react to a wide range of foods may require expert guidance to manage the condition. Removing many fruits and vegetables from the diet could affect the intake of vitamin C and other important micronutrients.

This article was first published in the September 2, 2017 issue of the New Zealand Listener.

MostReadArticlesCollectionWidget - Most Read - Used in articles
AdvertModule - Advert - M-Rec / Halfpage

Latest

A History of Magic reveals our compulsion to magical thinking
86134 2018-01-23 00:00:00Z Television

A History of Magic reveals our compulsion to magic…

by Catherine Woulfe

Harry Potter is the starting point for an enchanting documentary about the history of magic.

Read more
The awards season reckons with a new world
86173 2018-01-23 00:00:00Z Television

The awards season reckons with a new world

by Diana Wichtel

A tone of anger and uplift prevailed – thanks to #MeToo and Time's Up – as the first cab of the awards season left the rank.

Read more
Jacinda Ardern broke baby news to Winston Peters over tea and sandwiches
86125 2018-01-22 08:15:08Z Politics

Jacinda Ardern broke baby news to Winston Peters o…

by RNZ

Deputy Prime Minister got a home visit by Ms Ardern to break the news of her pregnancy.

Read more
Road toll: 'Without a doubt' increase is linked to police cuts
86121 2018-01-22 07:22:48Z Social issues

Road toll: 'Without a doubt' increase is linked to…

by Emile Donovan and Tim Brown

Nearly 100 dedicated road police positions have been cut in the past five years, while the road toll rose 50 percent increase in the same period.

Read more
New Mongrel Mob app 'bloody stupid' and insensitive
86117 2018-01-22 06:57:35Z Social issues

New Mongrel Mob app 'bloody stupid' and insensitiv…

by Emma Hatton

Gang violence mediators say a Mongrel Mob-themed game is 'stupid', but its maker says he was just taking advantage of a gap in the market.

Read more
Jacinda Ardern: Government's focus turns to '300-day plan'
86114 2018-01-22 06:38:40Z Politics

Jacinda Ardern: Government's focus turns to '300-d…

by Mei Heron

Labour's caucus meets for the first time this year, with the PM saying there are still policies to be finalised for the govt's first 100 days.

Read more
New Zealanders have long loved a good ghost story
86094 2018-01-22 00:00:00Z History

New Zealanders have long loved a good ghost story

by Redmer Yska

We New Zealanders are known for being down to earth and no-nonsense, but there's a surprising number of Kiwi stories with a supernatural element.

Read more
How to avoid burnout at work
86051 2018-01-22 00:00:00Z Psychology

How to avoid burnout at work

by Marc Wilson

Taking positive steps at work will help keep weariness at bay.

Read more