The enemy that lurks in the heat and dust

There is all that pollen to make you miserable if you are susceptible to hay fever. If you have certain types of eczema, the sun might make it worse. Then there are the bees and wasps - their stings are painful to us all, but for some they are lethal.

British Allergy Week opened yesterday to glorious sunshine, the kind that comes through the window in shafts, highlighting the dust suspended in the air - much of it dead skin scales and house dust mite droppings.

More than half of British adults

suffer from allergies, according to a survey published yesterday by Benadryl, makers of a proprietary allergy relief treatment.

The Living With Allergy survey found that 53% of adults reported having an allergy, with many saying they suffered associated psychological and emotional problems.

Of the 998 people over the age

of 15 who took part, 40% said their allergy made them feel irritable or snappy, while 29% said they felt miserable or depressed.

And while almost 20% of sufferers said their allergy affected their

work, more than 80% of employers were perceived to be unsympathetic

to their plight.

The most common allergies are caused by hayfever (22%), dust (18%), heat (15%), cosmetics or toiletries (14%), detergents (12%), and animals (10%).

Even by the age of 11, children are well on the way to being part of

these disturbing statistics. As we report today, allergies were the most common ailments reported by youngsters in the Glasgow area in a survey which showed fewer than half enjoyed good health.

For some, allergy can spell more than an itch or a runny nose. They are susceptible to anaphylactic shock, a potentially fatal allergic reaction to certain substances - peanuts, some drugs, insect stings - which provoke such a response that their respiratory system swells and chokes them.

There has been a lot of speculation about the possible causes for the increase in allergies, many of them related to otherwise beneficial developments in twentieth-century life - the combination of central heating, fitted carpets, and double glazing, all hospitable to the house-dust mite - and there are those who believe

that children born into obsessive hygiene and immunisation are being deprived of the immunological

priming which common childhood diseases used to confer.

Others see a psychological cause. Dr Mark Salter, a psychiatrist at St Bartholomew's Hospital, London, says: ''I believe that in times of duress, stress, and social pressure, many individuals who formerly have had little in the way of allergic difficulties develop allergic symptoms to a wide range of substances.''

For some, the source of their misery lies in the huge sweeping fields of

yellow that mark the march of

oilseed rape through our countryside. It is a major problem in the farming communities of eastern Scotland, but a doctor at the centre of it has expressed doubts whether oilseed rape is a true allergen.

Dr David Parratt, a micro-biologist who runs the allergy testing laboratory at Ninewells Hospital in Dundee, says: ''It seems to be more of an irritation. We don't know for sure what is going on, but it is different from a regular allergy and affects more of the population. What we can say is that some people who have never had an allergy in the past will have trouble with oilseed rape. I am near it all the time and have never suffered any problems. But there are some people who do.'' Dr Parratt and his colleagues take blood samples from patients, which have been sent in by GPs, and test them against their stock of allergens.

''We have about 300 so we need a list of suspects - you can't just go into it blind.

''The house dust mite is way ahead of everything else as a culprit, followed by grass pollens. After that there is a huge range, but you find that someone who is allergic to one thing is often reactive to something else. For example, someone allergic to mites may also be irritated by dander from horses or pets.

''We encounter people who have to follow a very restrictive diet because of the variety of foods they are reactive to. There are usually a number of things they can eat but it may be a fairly miserable diet compared to other people's.''

The British Allergy Foundation says this week is aimed at helping sufferers ''get to know their allergy''. Most would wish never to have made its acquaintance, but the week includes the launch of a network of local

allergy support groups.

n For more information contact the British Allergy Foundation helpline on 0891 516500.