Schools hit by swine flu were rescheduling GCSEs and A-levels today or asking for special consideration for pupils as the summer exam season begins.
It comes as Department of Health leaflets giving information about the virus began dropping through doors across the country.
Five schools, four of which are secondary schools, are now closed after students fell ill with the virus.
Alleyn's School in Dulwich, south east London, shut after five Year 7 pupils were diagnosed yesterday.
A sixth pupil, who visited the US during the Easter holidays, had already been confirmed with the H1N1 virus.
A statement on the school's website says contingency plans were being made for public exams this week.
It said: "Please be reassured that plans are already well-advanced to reschedule any planned exams for this week."
The school is contacting exam boards to arrange the rescheduling of Year 13 art exams and Year 12 modern language oral exams, headmaster Dr Colin Diggory said.
Paignton Community and Sports College in Devon was one of the first to shut after a 12-year-old girl contracted the disease, after holidaying in Mexico.
A statement on the school's website said: "The College is in contact with the examination boards regarding GCSE and post-16 exams which will be taking place shortly to ask for special consideration to be given to Paignton Community and Sports College in regard to the loss of six-and-a-half days education and the anxiety and stress our pupils are under at this time."
GCSE exams begin across the UK this week, with a design and technology practical exam, from the OCR board, due to take place on Thursday. It is not known if pupils at any of the affected schools are sitting this exam.
An Edexcel music technology paper is taking place today, but it is understood this is not being taken by the known affected schools.
A statement on Downend School's website said "no examinations will take place either at Downend or be relocated elsewhere for the closure period." Alternative arrangements are being made.
The South Gloucestershire school closed last week.
South Hampstead High School in north-west London said arrangements were being made for exams.
The Dolphin School in Battersea, south London, a private preparatory school, last night announced it was closing for a few days after two of its pupils fell ill with the virus.
The pupils are siblings and are close contacts of a previously confirmed case, the Health Protection Agency (HPA) said.
The HPA said closure was not necessary, but the decision was taken by governors as a precautionary measure.
Today's leaflet drop follows a Department of Health (DoH) announcement last week of a blanket delivery.
The leaflet suggests ways in which people can reduce their chances of catching swine flu and gives advice on what they should do if they develop symptoms.
The number of people confirmed with the H1N1 virus rose by a third yesterday.
Many of those who are newly diagnosed are said to have caught the virus from contact with people in the UK who had visited Mexico or the US.
Sophie De Salis, 12, one of the Alleyn's pupils with swine flu, told the Daily Mail: "I just felt like I had a cough and was under the weather. When I found out it was swine flu I was worried but really it just felt like a normal cold."
Some A-level students said they were concerned how the closure would affect forthcoming exams.
Charlotte Bailey-Wood, 17, is due to take French and Spanish oral exams in the next fortnight.
"I'm in my last year and the last thing I want is to catch anything that will hold me back from doing my best," she said.
Two adults who recently returned from Mexico - from London and the West Midlands - were also diagnosed with swine flu yesterday.
A DoH spokesman said: "There are now 27 confirmed cases in the UK - 23 in England and four in Scotland.
"The arrangements in place across the UK are continuing to ensure that we are well-placed to deal with this new infection."
World Health Organisation (WHO) spokesman Dick Thompson said yesterday that the agency may raise its pandemic level from five to its highest alert, level six.
Environment Secretary Hilary Benn said yesterday that Britain must remain vigilant.
Health Secretary Alan Johnson said earlier this week that he expected a second, more serious, wave of cases later this year.
The DoH's swine flu information line is 0800 1513 513.