Allergies and the Weather

According to the British Allergy Foundation, approximately one in four of the UK population will suffer from an allergy at some point in their lives, and the number of people affected is increasing by 5% each year.

Hay fever and the weather
One of the most common allergies is hay fever, which causes seasonal misery to millions of people in the UK.

Dr Mike Matthews was a GP in Harrogate for 30 years, and is now a Trustee for the Allergy UK (British Allergy Foundation). During his time as a GP he noticed a number of effects the weather had on his patients, particularly people new to the area.

The wind direction played a huge role in the extent of hay fever symptoms experienced by his patients. "In August, when the pressure over Harrogate was high, this brought winds in from the west, where there is a large heather moor. While the heather was beautiful to look at, it caused misery to hay fever sufferers!"

Wet weather meant less patients presenting with hay fever symptoms, while settled dry weather sent the numbers soaring. "People would know that the weather meant that their symptoms would get worse and would come in for repeat prescriptions (for their medication)."

"during the summer of 1976 the temperature was never below 75°F (24°C) for weeks. My recollections are of many people coming in with allergic asthma and hay fever."

Asthma and weather
Allergic asthma is another condition associated with changing weather conditions. Changes in temperature, an increase or drop, can trigger asthma attacks as can sudden changes in the weather.

It has been suggested that there are links between asthma attacks and levels of air pollution, particularly ozone, sulphur dioxide and nitrogen dioxide, which is affected by the weather, but despite the large amount of research the association is controversial.

Dr Matthews noticed "a few more cases of asthma during anticyclonic weather, particularly if there was an inversion and the roads were gridlocked."

Research has also associated an increase in asthma attacks with thunderstorms, particularly in the UK and Australia. A number of studies have suggested that in late spring, thunderstorms or a drop in temperature is followed by an increase in attendance at hospitals with asthma.

Further research suggested that this was related to rye grass pollen. These grains are normally too large to reach the lungs, but are broken up by raindrops releasing hundreds of tiny allergen-containing particles from each grain. These are small enough to reach the lungs.

Nearly half of patients in one study in the UK had never had symptoms before but reacted acutely to this seasonal combination of biological and meteorological conditions. In Melbourne, this connection actually resulted in "asthma weather alerts" on television.

Eczema and weather
Atopic eczema is an allergic condition, and people who suffer from other allergies are more likely to be affected. While the severity of the condition is often cyclical, winter and colder dry weather tends to make it worse. While hay fever sufferers dread the coming of spring and summer weather, those with eczema welcome the relief from their symptoms that warm weather brings.

A concoction of allergens
Although the research is not clear-cut, it has been suggested that a combination of certain air pollutants and pollen makes symptoms worse. People who suffer from hay fever may develop allergic asthma as well, although the asthma attacks often occur later in the pollen season and continue after pollen counts have fallen.

Keep up to date with the forecast
BBC Weather provide air pollution and pollen (during the pollen season) forecasts on the website, Ceefax and TV, so if you suffer an allergy as a result of either or both you can take whatever precautions necessary according to the forecast to limit your exposure to allergens.