Raw fruit

[AliT]

Can anyone tell me why I react badly to raw fruit (apples, pears, apricots, peaches, cherries, plums) but can eat all these fruits cooked, I can even eat most tinned fruit? If I eat them raw it gives me a very uncomfortable 'fluffy throat'!
Alex
(I can eat grapes, bananas and oranges without a problem?)

[Dr Adam Fox]

this sounds very much like Oral Allergy syndrome', where you have a pollen allergy and your immune system is getting confused as the protein in the fruit you mention look a lot like the pollen (usually birch) you are allergic to. There is a good article on this on Wikipedia. Fortunately, reactions are usually mild and as you say cooking or processing the fruit resolves the problem.

[Dr Helen Brough]

Dear AliT,

You have a classic example of oral allergy syndrome (OAS) to birch tree pollen cross-reactive fruits (stoned fruits and apples).

The allergy antibodies in your blood which respond to birch pollen are cross-reacting with proteins in these raw fruits. Thank-fully these proteins are broken down if the fruit is heated or processed which is why you can tolerate these kinds of fruits when processed. Usually OAS causes only mild symptoms in the mouth and throat; such as an itchy scratchy feeling but doe snot lead to more serious reactions.

The symptoms may be worse in the spring time when birch pollen levels are high. you may or may not suffer from hay-fever in the spring but will have positive allergy tests to birch pollen.

Unfortunately there is no treatment for this except for antihistamines you could take if you experience this acutely. There is little evidence that desentisation to birch pollen helps with OAS.

Best wishes,

Dr Helen Brough