A new report has predicted that the UK’s hay fever rates will double by 2030, as temperatures, pollution and urbanisation increase, leading to longer hayfever seasons and worsening symptoms.

 

 

The UK already has has one of the highest rates of hayfever in the world. According to NHS figures, around a fifth of the population is thought to suffer – a figure that rises to 37 per cent in teenagers. The condition can develop at any time over the age of two years but typically begins during adolescence or early adulthood, although late onset cases are becoming increasingly common. In addition, fewer people are ‘growing out’ of allergic rhinitis once they reach adulthood.

Who gets hayfever?

The exact reasons why some individuals develop hayfever are unclear, although there is a strong genetic link, as well as growing evidence to support the ‘hygiene hypothesis’. It is thought that suffering from few infections during childhood, together with a lack of exposure to endotoxins, increases the risk of hayfever by disrupting the development of the immune system. This theory is backed up by the fact that first-born children, children in small families and those in families with high incomes or standards of living have higher rates of hayfever.

According to Dr Jean Emberlin, leading hayfever expert and director of Pollen UK, the month of birth also influences an individual’s risk of hay fever, with those born during or just before the peak pollen seasons being most vulnerable. Exposure to cigarette smoke is another risk factor, she says.

But while these theories explain why certain individuals develop hay fever and others escape, it does not account for Britain’s high prevalence compared with other countries, such as Spain, where only 11 per cent of teenagers suffer – despite the longer, more potent pollen season.

Dr Emberlin’s research points to a dramatic rise in hayfever from the early 1960s until the late 1980s, with levels continuing to rise into the early 2000s, especially in teenagers. In England during the period 2001-2005, prescribing rates for allergic rhinitis increased by 41.7 per cent, although they have since dropped to around 1 per cent per year.

Dr Emberlin puts the increases down to better awareness, improved identification and changes to diet, air pollution and climate change. However, she believes that inappropriate use of antibiotics is another important factor behind the UK’s extraordinarily high hayfever rates.

“Antibiotics can disrupt the immune system and are associated with an increase in allergies,” she says. “NICE guidelines now limit antibiotic prescribing in under 16s but some GPs continue to prescribe them.”

According to Dr Emberlin, adult onset hayfever is often triggered by sudden lifestyle changes or dramatic events, such as having a baby or moving to a new area, while stress can also increase the risk and severity of the condition.

Climate change

Evidence from pollen monitoring records and vegetation surveys shows that some pollen seasons are starting earlier, while others are continuing for longer. For example, birch pollen, which affects a quarter of hayfever sufferers, is now in the air from late March (in the 1950s it was not released until April/May), while the grass pollen season, which used to end in late July, now carries on well into August in some areas.

Experts believe that the trend towards rising temperatures and mild, wet winters is responsible for these changes. Data from the Intergovernmental Panel on Climate Change and the World Health Organization show that average surface temperatures have increased by 0.7 degrees over the past 100 years, leading to earlier plant growth. Increased levels of carbon dioxide in the atmosphere are also giving plants an extended growth period.

Changing temperatures and weather patterns are also altering the distribution of allergenic plants, as seen with the arrival of ragweed ambrosia in the UK from North America. Another example is Pellitory-of-the-wall, a Mediterranean plant that is currently flourishing in southern England and the Midlands and expected to spread northwards as the climate continues to heat up.

If the Department for Environment, Food and Rural Affairs is correct, annual mean temperatures will soar by two to five degrees in the next few decades, while average rainfall will increase by 30 per cent in the winter and fall by the same level in the summer.

All of this research has led Dr Emberlin to predict in her report, ‘Hayfever and Climate Change’, that the number of hayfever sufferers will more than double, reaching 31.8m, by 2030. The potency and duration of symptoms will increase and those living in current hay fever hotspots will be hit hardest, she says.

Speaking at the launch of the report, which was published on behalf of Opticrom Hayfever Eye Drops, Dr Emberlin said that the effects of climate change on hayfever would have significant consequences for both individual sufferers in terms of “economic and social costs, together with decreased quality of life and exam performance”, while on a national level there will be “higher demands on healthcare” and “absences from work and decreased productivity”.

Urban misery

The regional prevalence of hayfever varies, depending on the length and severity of the pollen season in different areas. For example, the highest concentration of hayfever sufferers are found in the south central, south east and midland areas of England, where the pollen seasons are long and potent.

Scotland, which typically has short, mild pollen seasons, has low hayfever rates. Inland areas where there are no sea breezes are also worse affected. But, regardless of climate and latitude, GP consultation data indicates that people living in towns and cities are troubled more by seasonal allergic rhinitis than those based in rural areas.

This is supported by a German study (Behrendt and Ring 2012), which found that urban pollen had greater chemotacic activity on human neutrophils than rural extracts. Similarly, changes in the chemical composition of allergens have been observed in birch pollen that has been exposed to lead pollution and nitrogen dioxide from exhaust fumes (Bellanger et al, 2012).

Pollution is contributing to the UK’s growing hay fever problem

“There is an interaction between pollen, pollution and hayfever symptoms,” explains Dr Jean Emberlin. “Exposure to ozone and nitrogen oxides change the molecular weights of pollen grains, making them more allergenic, while nitrogen oxide makes the nasal membrane more permeable to allergens and also reduces the cilia beat of the nasal passages, meaning that allergens stay inside the airways for longer.”

Some experts predict that climate change will lead to increased levels of pollen, particulate matter and ozone, resulting in more hay fever sufferers in urban areas. Dr Emberlin’s report predicts that up to 45 per cent of inhabitants of big cities, such as London and Birmingham, will suffer from hayfever in the next two decades.

Symptom control

While changing temperatures and weather patterns combined with increasing air pollution and urbanisation spell bad news for hayfever sufferers, it is possible to reduce the impact of symptoms through medication and lifestyle interventions. The role of the pharmacist in managing hayfever symptoms will therefore become increasingly important as more and more customers seek advice and treatment recommendations.

Dr Emberlin advises sufferers to take note of the pollen forecast to find out when seasons are starting and ending and when high pollen count days will occur. She also advises avoiding drying clothes outdoors, and washing hair and changing clothes after being outside on a high pollen count day to minimise contact with pollen.

Many people find that fresh flowers, alcohol and fragrances can exacerbate their symptoms, so it makes sense to avoid these, while wearing wraparound sunglasses and applying a barrier balm around the nostrils may help prevent pollen from irritating the eyes and entering the airways.

Inappropriate use of antibiotics is an important factor behind the UK’s extraordinarily high hayfever rates

Over-the-counter medications can help to reduce the severity of hayfever symptoms significantly but evidence suggests that not everyone gets the maximum benefit from these. “Adherence is key to treatment success and pharmacy staff should use the time they have with customers to reinforce the importance of using the selected hayfever product correctly to ensure optimum relief,” says Stuart White, marketing manager for Omega Pharma’s hayfever portfolio.

It’s also important to explain the different types of products to customers, he says. Most hayfever sufferers rely on oral antihistamines to manage their symptoms and may not be aware of the benefits of other treatments, such as nasal corticosteroids and eye drops containing sodium cromoglicate. Pharmacy teams can keep up to date with the help of a free hayfever training module.

With hayfever symptoms lasting longer than usual and with more and more people experiencing late onset hayfever, White warns pharmacists to prepare their teams for customers who have been misdiagnosed with a cold. “Pharmacy staff should have the knowledge to distinguish between these conditions. Utilising the WWHAM approach will help pharmacy teams to identify hayfever symptoms,” he says.

And if symptoms persist or develop in late summer or autumn, Dr Emberlin urges people not to “overlook fungal spores as a cause”, as these “can affect people throughout the year, but are most prevalent in October and November”.