Breakfast in the back garden may not sound particularly dangerous, but for Jane Murray it was the prelude to a tragedy. Within a matter of hours of sharing breakfast with her husband, she was in a coma. The wasp took less than five seconds to deliver its deadly sting, but it was another three years before Jane Murray died. She spent the remaining time in a coma.

Murray, wife of Charlton Football club chairman, Richard Murray, sat down to enjoy a leisurely start to the day on that tranquil September morning in 2000. The result was devastating.

As her husband of 27 years looked on, Murray, 50, suffered an unexpected and severe allergic reaction to the sting. She was rushed to hospital from her Surrey home but lost consciousness and slipped into a coma from which she never emerged.

Her death almost three years later was announced on the Premiership club's official website last week. Fans have since posted tributes and expressed support for Murray's husband and two sons, James and Andrew.

Being stung is a hazard that is often accepted as an unpleasant but common consequence of a British summer - tennis star Kim Clijsters was stung on her stomach during her Wimbledon semi-final this year, but played on. Experts believe that only one or two out of every 1,000 people stung by a wasp or a bee suffer any kind of allergic reaction, and the symptoms can vary in their severity. Cases like Murray's, where a life-threatening reaction develops, affect under 1/2% of the population.

Wasp and bee stings trigger the release of chemicals, including histamine, from cells in the blood and tissues where they are stored. An allergic reaction happens when the body's defence system overreacts.

Anaphylaxis is a severe allergic reaction - the extreme end of the allergic spectrum. The whole body is affected, often within minutes of exposure to the allergen, but sometimes hours later. In such cases, the blood vessels widen, causing the sudden severe lowering of blood pressure, an itchy, raised rash can form and there is often swelling of the tongue and throat which makes it very difficult for the victim to breathe.

Earlier this month Graham Williamson, 47, from Hampton in Arden, collapsed in his back garden and stopped breathing after being stung on the foot by a bee while mowing his lawn. The sting caused his bodily systems to shut down and his blood to stop clotting.

The 6ft 5in amateur cricketer, who was nicknamed "Hulk", was taken to nearby Solihull hospital and put on a ventilator in the intensive-care unit where doctors sedated him to give his system time to recover.

As his wife Julie and their three sons kept a vigil at his bedside, the company director's health went into decline. He suffered kidney failure and died last weekend.

It is estimated that between two and nine people die as a result of allergic reactions to bee and wasp stings in the UK each year. In addition the unexplained deaths of some people over 40, although attributed to heart failure, may in fact have been caused by stings, according to the Anaphylaxis Campaign, a charity that provides information and advice about severe allergic reactions.

Venison trader Mike McShane, 48, was stung on the back of his neck by a bee during a walk near his cottage in the Scottish Highlands last month. It was several hours before he began to feel unwell, but the father-of-two later died in hospital from anaphylactic shock.

It is often difficult to know whether a person is going to have a severe reaction to a sting. Although the first ever wasp or bee sting someone gets may be painful and give rise to local swelling, it is not usually dangerous. An allergy may be triggered by the earlier sting, but victims often don't realise they are susceptible until they are stung again. When someone has a severe reaction, sometimes the next incident, especially after many years, may cause no reaction at all.

"One of the strangest things is that when people have had a severe reaction, 40% of them do not have a reaction to the next sting," says Dr Bill Frankland, a consultant allergiest at the London Allergy Clinic. "This is particularly true in the case of children."

Dr Frankland, who has had anaphylactic shock himself, explains that there is little difference between a bee and wasp sting. "The catastrophic results are the same if you are going to become severely allergic to them," he says, adding that there was also no evidence to suggest that if you have an allergy to something else then you are more susceptible to bee and wasp stings.

If treated quickly enough, anaphylaxis can be reversed with an injection of adrenaline, and doctors recommend that people diagnosed as being susceptible should carry adrenaline with them at all times. Patients can also be cured of the allergy with a course of "immunotherapy" injections over several years, but this is only available at a few centres in the UK.

Those working in the field argue that a lack of resources means that many acute sufferers are not given the help they need. "The problem that the patient often faces is getting proper, high-quality advice," says David Reading, director of the Anaphylaxis Campaign. "It can take up to two years to get a referral to an allergy clinic in the NHS. It is unacceptable that in many cases people are not able to get solid, quick medical guidance. This is all down to the poor state of allergy services in many parts of the country.

"It is to do with the fact that allergy isn't high enough up the list of priorities, despite the fact that it can be life-threatening. We are campaigning for this to change."

The sting - what you need to know

Symptoms
A bee or wasp sting may cause gross swelling at the site of the sting. This is not dangerous. But a few people - under % of the population - may experience a severe, generalised allergic reaction known as anaphylaxis. The symptoms may include:

· an itchy feeling
· difficulty in swallowing
· hives anywhere on the body
· generalised flushing of the skin
· abdominal cramps and nausea
· increased heart rate
· a sudden feeling of weakness (a drop in blood pressure)
· a sense of doom
· collapse and unconsciousness
· difficulty in breathing - due to severe asthma or throat swelling.

Not all these symptoms would necessarily be present.

Avoiding insect stings
· Avoid wearing shiny or brightly coloured clothing, flowery prints, or black, as these seem to attract insects more than white, green, tan or khaki clothes

· Wear shoes at all times when out of doors

· Avoid using strong perfumes during the summer. Many products, such as suntan lotions, hairsprays, hair tonics and other cosmetics, contain strong perfumes. Test before you buy

· If possible, keep your arms and legs covered

· Use an insect repellent containing diethyl-m-toluamide whenever you will be outside for some time, especially if you are alone

· If a bee or wasp comes near you, do not try to swat the insect but move away slowly and calmly. If the insect lands on you, try not to panic. Keep calm and be patient. The insect will usually fly away after a few seconds

· Make sure that you leave no crumbs or drink on your face which will interest the insect

· If you find many wasps or bees in your house or garden and suspect that there may be a nest nearby - perhaps in the roof or a nearby tree - phone the local authority or a pest-control expert to come and remove the nest. Do not try and do this yourself

· If you are planning to eat outside, find an area where there are no wasps or bees before you start eating. It is better to bring your picnic

inside than to risk being stung

· Food attracts insects. When outside, avoid open rubbish bins and keep food covered. Always look at what you are eating before you take a bite or a sip of a drink, as wasps will slip into food and even into open drink cans. Boxed drinks with a straw may be safer, but keep an eye on the straw

Treatment
Local reactions, however large and painful, will usually respond to an antihistamine. But the treatment for a generalised allergic reaction is adrenaline (epinephrine). Because this must be administered without delay, patients known to be at risk often carry their own adrenaline-injection kit for use in an emergency. The injection many allergists prescribe is the EpiPen, an easy-to-use device with a spring-activated concealed needle.

If there is no epinephrine available, go to the nearest hospital accident and emergency department.

· For more information on the Anaphylaxis Campaign, visit www.anaphylaxis.org.uk