While most of us may think that the hayfever season ends when summer does, there are, in fact, several hayfever seasons, and for a large proportion of the population each one brings new torment. In spring, tree pollens can cause suffering. In summer, grass pollens bring misery to the majority of sufferers, then autumn brings a final flurry of fungal spores and autumn flower pollens to contend with.
Global warming is now playing a key part in our ongoing woe: our changing climate is bringing earlier summers and more pollination, while environmental pollution traps pollens in the atmosphere.
When and how much pollen is released from plants also depends on day-to-day weather cycles. Because many plants require exposure to a certain amount of heat before they will release their pollen, a cold or wet spring may delay the release of tree pollen by weeks. Pollen release also varies depending on the temperature, humidity, rainfall, wind and sun.
Early mornings are generally the worst time for pollen concentrations because, at that time of day, plants are busy pumping out pollen and this easily accumulates in the still-stable surface air. As the atmosphere heats up on a sunny morning, warm air rises and cool air falls, adding pollution, dust and pollen to the mix already present. Pollen released in the early morning can travel hundreds of miles from its source on the prevailing winds, which is one reason why cities can have high pollen counts even if they have very little vegetation.
Interestingly, while high winds can distribute irritants and allergens over a wide range, they can also reduce the size of the particles in the air. Most physicians believe that this should equate with less respiratory illness. But small particles may also slip more easily into the respiratory tract, causing allergic-type flare-ups.
Misery for millions
Hayfever affects an estimated 15 million people in Britain and its incidence has tripled over the past 20 years. It affects 30–40 per cent of children, with most of them having their first experience of hayfever symptoms in adolescence In medical jargon, all these people suffer from seasonal allergic rhinitis – an allergy in the nose. The first symptoms are an itching nose, mouth, throat and eyes, followed swiftly by the all-too-familiar sneezing, nasal discharge, sore and watery red eyes and blocked nose.
Frequently, there’s headache caused by pressure in the sinuses, plus swelling and inflammation of the membranes of the nose, the pain of which can be almost unbearable.
Like asthma and other atopic disorders, such as eczema, the basic cause of this condition is an exaggerated immune response to allergens; this in turn releases histamine into the nose, leading to inflammation.
Symptoms or side-effects
With so many millions of people in Britain – and indeed throughout the world – suffering from hayfever, it’s important that sufferers find something that relieves symptoms and is safe. While there are many conventional medical approaches to hayfever, few are problem-free.
Among the prescription-based medicines, steroid tablets have serious side-effects, such as diabetes, osteoporosis and blood vessel damage. They are particularly unsuitable for children.
Steroid-based eyedrops, although these may be effective, can also be dangerous over the long term, causing glaucoma, cataracts, corneal damage and, ultimately, blindness. Steroid-based nasal sprays are considered a safer option but steroid injections can be fatal.
Decongestant tablets or nasal sprays, available both by prescription and over the counter, will reduce a blocked nose in the short term, but tend to leave you with a worse problem when you stop using them. They also have devastating side-effects. Many hayfever remedies can now be bought without prescription. Phenylpropanolamine, found in over-the-counter (OTC) medications, can cause strokes, making them particularly dangerous for people with high blood pressure.
Antihistamines, despite being claimed to be both effective and safe, can also cause a variety of sideeffects – such as headaches, rashes, photosensitivity, gastrointestinal problems and heart arrhythmias.
The most potentially dangerous side-effect is drowsiness, which may lead to fatal accidents.
According to the British Allergy Foundation, the problem of drugdriving could become as serious a threat to road safety as drink-driving. Its data suggests that road accidents involving people under the influence of legal drugs such as hayfever remedies have soared by 600 per cent in the past decade.
In a recent survey by insurance company Privilege, one in 10 drivers – the equivalent of 3.3 million people – admittted to losing concentration at the wheel due to an impaired reaction caused by illness or medication; and yet almost half (45 per cent) of the drivers surveyed admitted to having driven while taking medication. A quarter admitted to rarely or never checking the side-effects of their remedies before setting off, and just under a quarter believed there was nothing wrong with driving while on any hayfever or allergy medication.
Drowsiness from antihistamines can be detrimental in other ways. Research suggests that nearly threequarters of students taking hayfever medication can expect to drop a grade in their exams, as ingredients in the most popular remedies interfere with their ability to concentrate.
Hayfever remedies that contain chlorpheniramine K can cause drowsiness, while those with loratidine, cetirizine, acrivastine, desloratidine, levocetirizine or fexofenadine are considered non-drowsy.
In fact, all antihistamines can cause some degree of drowsiness. The only non-drowsy antihistamine would be one that did not cross the blood/brain barier. All antihistamines cross this barrier and as such cannot be considered completely non-sedating even at the recommended dose, and individual susceptibility to this – and to other adverse effects – cannot be predicted.
The best prevention for hayfever is to have allergy-free parents. If either your mother or father has an allergy, you’ve got a 40 per cent chance of having it too. Failing such foetal foresight, consider the following:
• Relax. Stress can trigger the release of excess levels of melatonin, high levels of which can affect vulnerable people, such as asthmatics.
• Buy an ioniser. Ionisers release negative ions into the atmosphere to counter the over-abundance of positive ions in a man-made environment. Positive ions are associated with triggering increased histamine release.
• Check for common food allergies (e.g. to milk, wheat and eggs), as well as uncommon ones (e.g. to particular fruit and vegetables). They may be exacerbating your symptoms.
• Keep windows and doors closed on high-pollen days; change your clothes and wash your hair when you come in.
• Keep your bed pollen-free: cover it with a spare sheet during the day, and roll this up carefully before going to bed.
• Dry clothes and bedding indoors, to avoid them picking up pollen.
• Keep away from pets who have been outside and avoid grooming them yourself.
• Avoid smoky or polluted places.
• Get somebody else to mow the lawn.
• Wear wrap-around sunglasses to keep pollen from your eyes. Try not to rub irritated eyes as it causes further swelling.
• Be patient. Hayfever often eases with age, especially if it came on before age 30.
This article first appeared in the Ecologist September 2007