Beating hay fever

The sneezing season….

The arrival of summer is not welcomed by everyone. The longer evenings, better weather and the flowering of plants in gardens and in the countryside may herald the onset of sunnier times for most people. But for those with hay fever, the blooming of nature means pollen and pain. Early summer is the 'sneezing season' dreaded by all sufferers of hay fever.

Hay fever, or seasonal allergic rhinitis as it is known medically, is an allergic reaction to pollen and spores, the microscopic grains that plants, trees, grasses or fungi use for fertilisation. In spring, plantlife comes into bloom and many forms of trees, grasses, fungi and flowers release pollen and spores in order to reproduce. While many plants rely on insects to transfer their pollen, others release their pollen onto the wind. It tends to be this wind-borne pollen that causes problems for people with allergies.

High levels of pollen in the air can ruin summer for hay fever sufferers

"Hay fever won't kill, but it can cause a severe deterioration in many people's well-being", South Dublin GP, Paul Carson explains. As someone with a special interest in the treatment of allergies, Dr Carson recommends that people who suffer from hay fever should take pre-emptive action by visiting their GP and working out a treatment plan in advance of the high pollen season.

"The condition mostly affects the nose, blocking it up or making it itchy and runny", he adds. "Sinuses can get blocked too, causing headaches. In severe pollen reactions, the whites of the eyes can swell up to a jelly-like substance and bulge from the eye socket, which is not only unsightly but extremely uncomfortable".

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A honey bee gathering pollen

Hay fever is a name that covers a range of different allergic reactions, all of which peak around the same time of the year. Some people are allergic to the spores released by certain fungi, though this is not a major cause of hay fever. Fungi are more easily avoided than the plants, flowers and grasses, which are responsible for most cases of allergic rhinitis. When we think of pollen, we tend to envisage the fine yellow powder that gathers on the calyxes of flowers, but trees and grasses also spread pollen. The pollen of the birch tree is one of the most prolific pollen allergens in Britain and Ireland.

"Grass pollen is the most common allergen in Ireland without a doubt", says Dr Paul Dowding, a senior lecturer with the Trinity College Dublin botany department. "Herb pollen is less common and tree pollen is not a great factor in Ireland because it is not a heavily wooded country. The highest pollen count levels within Ireland are usually found in lowland country areas, especially agricultural areas where there is likely to be a lot of grassland. Levels in cities would be a half or quarter of that and in coastal areas pollen levels would be lower again".

Grass pollen is implicated in most hay fever allergies in Ireland and Britain, as up to 90% of people with hay fever are allergic to it. A person with hay fever may simply be allergic to grass pollen, or they may be allergic to a number of other varieties of pollen too. Only allergy testing will establish what a person is actually allergic to. Pollen allergies seem to relate to the climate and vegetation of the country. In Scandinavia birch pollen is the most common allergen, while in parts of Spain pollen from the olive tree is the most prolific cause of hay fever.

Hay fever is actually a relatively modern illness. It was almost unknown before 1800 but it has become extremely common worldwide during the last century. The first case of hay fever to be described medically was in 1819 but the allergic cause of the illness was not identified until 1873.

Medical statistics show that the incidence of hay fever rose steadily throughout the 19th century in many countries including France, Germany and the United States. The number of people affected by hay fever has continued to rise and the illness is now common in countries like Japan where it was unknown only 40 years ago.

Summer cold

According to Dr Carson, hay fever is still unknown to many people, at least in so far as they might understand it to be a possible cause of their symptoms. "As many as 20% of the population have some form of allergy", he explained. "Half of these have serious conditions, such as asthma, eczema or severe food allergies. Many of the others put up with minor symptoms, or explain them away as summer colds. Many doctors even will not recognise hay fever when it is presented to them".

Some research suggests that air pollution may make hay fever worse but the evidence is not clear. Studies in countries such as Sweden, Italy and Spain have shown that hay fever rates are greater in cities than in the surrounding rural areas where pollen counts are higher.

In Japan, the highest incidence of hay fever can be found in populations living alongside busy roads, implying that vehicle exhaust fumes are contributing to the problem. This is very possible as diesel particles have been shown to make people more susceptible to allergens.

"City dwellers do seem to suffer worse because of the combination of pollen and diesel fumes, which can make life especially hard for them", says Dr Carson. "I have some patients who simply prefer to spend the entire summer by the beach, where the clean air blowing in from the sea provides them with excellent relief. But in city or country, all people with hay fever feel bad. Some just deal with it better than others".

Because pollen can be carried for long distances, sometimes many miles, people with hay fever can often feel that there is no escape from pollen during the spring and early summer season. Samples of ragweed pollen have been collected 400 miles out to sea and have been detected at altitudes of two miles high. A single ragweed plant can generate as much as a million grains of pollen a day, enough to get up anybody's nose.

In Ireland, the high pollen season begins sometime in June, depending on which part of the country you happen to live. Obviously, there is seasonal variation and the exact start date will depend on what the weather is like throughout March, April and May. The warmer weather in South West Cork means that the grass pollen season tends to start there in mid-May. In Dublin and the midlands the high season usually begins at the start of June and in North West Donegal a fortnight later.

"The earliest onset of the pollen season in Ireland was the last week in May one year", says Dr Paul Dowding of Trinity College Botany Department. "The latest recorded onset was the last week in July. The better the weather, the shorter the pollen season is, but pollen levels will be higher. If the summer is bad, pollen levels will be lower, but the season will last longer. It's a catch-22 for people with hay fever".

Peak times

As in other countries, the worst days in Ireland for hay fever sufferers are hot, sunny days with light winds and no rain. The heat and sunshine encourages plants to open their pollen sacs, the wind disperses the pollen and the lack of rain means that the pollen remains in the atmosphere longer.

According to Dr Dowding, pollen counts in the country are generally four or five times higher than in Dublin. However, the greater concentration of pollutant particles in the city might aggravate the incidence of hay fever in the capital. In towns and cities, the evening is the peak time for pollen, whereas in the countryside the afternoon is the worst time of day for sufferers.

"The larger the city and the hotter the day, the later the daytime peak", explains Dr Dowding, who is responsible for providing Met Eireann with pollen count data. "In grassy rural areas the count may be temporarily high around mid-morning, but the peak occurs between 4pm and 7pm. On hot sunny days, pollen counts are always lower on the beach than inland, where country areas can have a pollen peak from 3pm to 8pm. In cities, the peak usually comes in the early evening".

Under the microscope - oak tree pollen

Hay fever sufferers experience the well-known symptoms of a pollen allergy. A stuffed or runny nose is often accompanied by sneezing. Overproduction of mucus can lead to coughing, watering eyes and a postnasal drip. In some, the eyes, nose and throat can develop an itch, while others find dark circles appear beneath their eyes, due to an increased flow of blood near the sinuses.

This happens because people with hay fever are producing an antibody within their bodies. That antibody latches onto a cell that contains many chemicals. When an allergen, such as pollen, comes in contact with the antibody in the cell, allergic symptoms begin. Usually, the body releases a chemical called histamine as the first stage of an allergic reaction. Histamine causes the itching and watering in the nose and the eyes that we associate with hay fever.

With the onset of hay fever symptoms, many sufferers might mistake their allergic reaction for a springtime cold, as the symptoms are so similar. The clue to whether it is hay fever is longevity. The symptoms of a cold will ease after a few days, whereas the symptoms of hay fever, like any other allergic reaction, will remain as long as the sufferer remains exposed to the allergen - pollen.

Rain brings relief

Rain can offer some welcome relief to people with hay fever, as it washes the pollen out of the air. Rainfall in the morning will nearly always keep the pollen count down to low or moderate for the rest of the day. In Ireland, this means that some people with a mild allergic reaction can actually go through a poor summer without realising that their cold-like symptoms are in fact a pollen allergy, as regular rainfall continually eases their symptoms. However, rainfall is often followed by an increase in pollen as plants ingest the rainwater and bloom all the more.

The first port of call for many people with hay fever is the pharmacy, where they can obtain antihistamine based treatments or steroid nasal sprays. Antihistamines do not treat the blockage of the nose, so often patients end up going to their doctor to obtain oral steroids that will unblock their nose. Once it is unblocked, a steroid nasal spray will then effectively reverse the symptoms that cause discomfort.

Hay fever symptoms can be alleviated by a wide range of over the counter products, these days. Predominantly, these contain antihistamines, drugs which block the production of histamine in the body, thereby preventing the runny nose and itchy, watering eyes. Some people find that it is enough simply to address their most problematic symptom, treating their blocked nose with a nasal spray or oral decongestant to improve breathing.

A short time ago, a new antihistamine was introduced to the Irish market that also unblocks the nose and so can be taken alongside a nasal spray. It is important to use such over the counter preparations sparingly, as they often have side effects that can impair concentration.

"Over the counter preparations can cause drowsiness and can react with alcohol", warns Dublin GP, Dr Leonard Condren. "People should be careful with machinery or driving a car. Newer hay fever medicines have less prominent side effects, but it is still a risk people need to be aware of".

"Many patients only come to their doctor in the middle of the hay fever season, having already used decongestants and other over the counter treatments that have not relieved their symptoms", says Dr Paul Carson. "At that stage, they can be desperate for relief, which might come in the shape of a short course of high dose oral steroids". These dramatically reverse the symptoms of blockage and irritation, allowing other treatments to be then used effectively, he says.

Decongestants

He says that with decongestants, there can be an increase in symptoms by using nasal decongestants continually over time. If some decongestants are used injudiciously, the problem of rebound can arise. "Rebound refers to the phenomenon where overuse of decongestants actually rebounds on the user. The medicine no longer treats the symptoms, but actually begins to aggravate them. This can lead to Vasomotor rhinitis, a condition with symptoms identical to hay fever, but is a much more intractable problem", Dr Condren says.

"If over the counter treatments have not sorted out the problem, there are prescription decongestant sprays and steroid sprays that a GP can prescribe for a patient", explains Dr Leonard Condren. "For very severe, incapacitating cases, a doctor might prescribe oral steroids. The steroids work by suppressing the inflammation within the tissue of the nose. Steroids can take down the swelling and lower the level of the secretion of mucus".

Dr Paul Dowding recommends that people with hay fever take their allergy to the seaside. He believes that the best way to beat hay fever when the sun shines is to go to the beach for relief.

"You can treat the symptoms of hay fever with over the counter treatments and you can avoid the peak periods during high pollen days by simply staying indoors and keeping all the windows and doors shut", he says. "However, there are a lot of pluses to going to the seaside. On a high pollen day, with a light breeze, you will actually get clean air off the sea if you go to the beach".

No one who has any form of allergy should smoke or go into smoky environments, advises Dr Carson. "Nor should they be working in industrial environments where there is smoke, dust or chemicals in use. These guidelines count for hay fever patients too, as all of these atmospheric pollutants can aggravate their condition. They can avoid pollen by closing their windows against it, whether in the car or in the house. The build-up of heat is less uncomfortable than the onset of hay fever symptoms".

By going to the doctor or pharmacist before the onset of the pollen season, people with hay fever stand the best chance of getting through the sneezing season without having their summer ruined by an allergic reaction. Then, armed with suitable medication to prevent the onset of the symptoms, they can hope to enjoy the good summer weather (when it arrives!) like everyone else.


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