"It's difficult when I see people eating things I would like to try - but I know that I can't". Alexander Lambert, 15, is allergic to some fruit
Cases of oral allergies to fruit and vegetables are rapidly increasing, according to a British specialist.
Dr Pamela Ewan, an allergy consultant at Addenbrooke's Hospital in Cambridge, said the rise in cases appears to be outstripping even peanut allergies.
Dr Ewan, who sees more than 8,000 people with allergies a year, said most patients with reactions to fruit and vegetables were youngsters.
Symptoms include swelling in the mouth and throat, and breathing difficulties.
ALLERGY OR INTOLERANCE?
An allergy is when the immune system reacts to a harmless substance such as a food or pollen, as if it isn't safe
A severe allergy can cause a potentially life threatening shock known as anaphylaxis
An intolerance does not affect the immune system
An intolerance is generally not life threatening and the symptoms less severe
An intolerance is being unable to digest certain foods such as lactose in milk
She said: "We have seen a big rise in the number of cases in the past four to five years.
"It is a bit like the peanut allergy was the epidemic of the 1990s. I think fruit and vegetables are becoming the epidemic now.
"In term of numbers, fruit and vegetables are the new form of peanut allergy."
Dr Ewan urges parents to take the problem seriously.
"We think fruit and vegetables are healthy, which they mostly are, but you can be allergic to them."
"Early on when we first picked it up, it was passed off as not being serious. It began with fairly mild itching in the mouth.
"But now we are seeing people who are getting really severe throat closure, a significant swelling at the back of the throat which can impede breathing."
Reaction to bananas
One of her patients is Alexander Lambert, a 15-year-old schoolboy from Essex. He first discovered he had a reaction to bananas when he was 11.
Tests have since proved positive to other fruits. Alexander said that now he even has to be careful about what fruits other people can eat around him for fear of triggering a reaction.
Allergy specialist Dr Pam Ewan: "Peanut allergy was the epidemic of the 1990s - fruit and vegetables are the epidemic now"
Other specialist centres in the UK have confirmed to the BBC that allergies to fruit and vegetables is a growing problem.
Dr Adam Fox, a consultant paediatric allergist at Guy's and St Thomas' Hospital in London, said: "We are certainly seeing lots of oral allergy syndrome.
"This affects people who are actually allergic to pollen - such as birch pollen.
"There is a cross-reactivity between the protein in that pollen with those in fruit and vegetables, so people start getting a reaction to fruits such as apples and pears.
"Normally we would see this among young adults as they start to develop hay fever but we are starting to see more of it among young children.
"As there is more allergy, the severity seems to be increasing and the patterns are changing."
Pollution a factor
Whilst allergy to hay fever is seasonal, allergy to fruit and vegetables can continue all the year round.
Dr Jonathan North, from Birmingham, agrees with Dr Fox. He believes that particles from diesel exhaust may be making the situation worse as these make pollen more allergenic.
He said: "Fruits are a particular new problem, possibly due to similarities between the proteins in some tree pollens, birch especially.
"The chance of cross-reactions with fruits increases with the larger number of types of fruit to which we are exposed."
Dr Paul Williams, a clinical immunologist at the University Hospital of Wales, has also seen a rise.
"There is a real increase in the number of patients seen with Oral Allergy Syndrome in the specialised allergy service we run.
The records indicate a five-fold increase in the rate of oral allergy syndrome in the same six year period, albeit from a low base.
The rate of final clinically diagnosed cases rose from about one for every 100,000 of the population in the Cardiff and South Wales area, to five in the year 2007/8.
However, the centre emphasises that it does not yet know why this is.
It could, for example, be due to improved diagnostic procedures.
Many of the consultants contacted by the BBC have raised concerns that the UK has inadequate resources to cope with the growing demands being placed on allergy services.
They say there are too few specialist centres and specialists.
Dr Ewan estimates that, with the current facilities, it would take 50 years to see all the people estimated to be currently suffering from severe or complicated allergies.
But the Department of Health says it is responding to rising demand with an increase in staffing. It is also planning a pilot allergy centre as a potential model for the future.
On the BBC News website tomorrow: How much is the modern, Westernised lifestyle to blame for the allergy epidemic?