A-levels and GCSEs have been disrupted by hay fever, a study says
One in five children sitting examinations this summer will achieve worse grades than expected because of hay fever, a survey suggests.
Almost a quarter of seven to 18 year olds said they suffered from the pollen allergy.
Of these, 40% were aged between 15 and 18, the stage when most people sit GCSEs and A-levels, the research group BMRB International found.
Allergy therapist Michael van Straten said the symptoms - including a runny nose, itchy throat, lack of concentration and depression - could have an effect on revision and exam performance.
He said: "Bad as it may be to go into an exam with runny eyes, a streaming nose and a sore throat, it may not be as bad as falling asleep."
The survey found 36% of hay fever sufferers believed it had affected their performance at school.
Problems included having to take days off, missing school activities and a poor attention span.
Hay fever, suffered by around 7 million people in the UK, is caused by breathing in pollen or by it entering the eyes.
It is common from early spring to late summer. Tree pollen is the usual cause during the spring and grass pollen during the summer.
John Guy, principal of The Sixth Form College in Farnborough, Hampshire, said: "Hay fever hits when youngsters are likely to be assessed and when national exams take place and therefore it is of significance.
'Red, streaming eyes'
"You can see these children suffering in exams, whether it's Sats (the tests sat by seven, 11 and 14 year olds), GCSEs or A-levels.
"You see them, with red, streaming eyes and they look miserable and unwell.
"The impact of that on their achievements is likely to be significant. If you can take measures to prevent that then I think you should."
The incidence of hay fever has doubled in the last 25 years.
Dr Guy stressed that the cumulative effect was a concern to parents and teachers and urged children to take treatment.
He said: "Cumulative illness and cumulative absence is always detrimental to a youngster's education and hay fever is an illness that is often underestimated.
"My concerns have been raised by this survey because of the increase in the reported incidence of hay fever and the increase in assessment which is taking place during the summer."
The survey, of 612 children, was carried out on behalf of Herbal Concepts, which produces allergy remedies.