'Frightening' increase in asthma cases over just two years baffles doctors

'Four Weddings' actress Charlotte Coleman was the latest victim of a disease which now affects 5m Britons

One of the biggest studies of asthma is this week expected to reveal a "frightening" increase in the number of British people suffering breathing-related diseases.

The report by the British Thoracic Society, The Burden of Lung Disease, will amount to the most comprehensive independent survey of the incidence of asthma and other respiratory conditions in recent times.

News of its publication came as it emerged that Charlotte Coleman, 33, a co-star of Four Weddings and a Funeral , has been found dead at her London flat, after apparently suffering a severe asthma attack. It also follows the recent death of pioneering heart transplant surgeon Christiaan Barnard, who collapsed with an asthma attack while on holiday.

The BTS is refusing to release specific details of the report's content before Tuesday; the society's chairman Dr Martyn Partridge, told The Independent on Sunday last night that it would include "frightening data about the proportion of people in the UK with respiratory disease".

It is understood that it is likely to include figures showing significant rises in the number of diagnoses of asthma and other respiratory diseases among both British children and adults.

News of the research comes barely two months after an audit by the National Asthma Campaign revealed that the number of UK asthma sufferers had risen by 50 per cent in the preceding two years. The survey revealed that 5.1 million UK residents – equivalent to one in 13 adults and one in eight children – are being treated for the disease. A previous audit by the same pressure group, published in June 1999, gave a figure of 3.4 million.

Yet Professor Stephen Holgate, one of Britain's leading authorities on asthma and a professor at Southampton University's School of Medicine, says that "sudden" deaths, as Ms Coleman's appears to have been, remain rare.

"Asthma tends to be managed much better now than it used to be, so what appears to have happened is quite surprising," he said. "What usually leads to a death is that someone gradually deteriorates. They put off going to the doctor, and eventually something does suddenly happen."

Dr Holgate is due to give a speech at the Royal Institution in London on Wednesday, in which he will emphasise his belief that the "tendency" to develop asthma is inherited. He will also call for more research into Xolair, a potentially revolutionary drug that, if regularly injected by asthmatics, combats the allergic antibody responsible for blocking the breathing passages.

Dr Partridge said that the main "trigger" in the development of asthma was still thought to be exposure to allergic agents such as dust mites during childhood. Once diagnosed, it could be exacerbated by other agents, including cigarette smoke and pollutants. He said that the rate of diagnosis had risen alarmingly in recent years: the most recent statistics show a 30 per cent increase in the detection in UK adults between 1991 and 1996. Among the factors being blamed are poor dietary habits and falling immunity levels.

While the number of people dying of the disease annually had dropped from around 2,000 five years ago to 1,600 last year, the likelihood of a "sudden" critical collapse was greatly increased if sufferers tried to ignore symptoms and failed to take medication.