The exceptionally warm weather this spring may have been a welcome surprise to some, but for many of the UK’s estimated 17 million hay fever sufferers it meant an unwelcome early kick-start to the year’s grass pollen season. The fine weather forecast for early June will reap further misery, as more grass pollens are released. The key to maintaining a good quality of life through this difficult time is to be prepared with adequate information and a strategy which combines sensible allergen avoidance with appropriate medication or treatments. As a community health care professional, you’re in an ideal position to support patients and their families, by offering advice on hay fever before the pollen seasons start and providing ongoing help to control symptoms.
Hay fever, also known as pollinosis, or seasonal allergic rhino conjunctivitis, is an upper respiratory tract disorder presenting as an allergic reaction to pollen and spores. Inflammation of the mucous membranes inside the nose is common and other symptoms include frequent sneezing, mucous production, itchy eyes, nose and palate. Sufferers often have congested noses, feel tired and may have trouble sleeping.
Hay fever often starts in childhood and may occur regularly at the same time each year. It develops ingenetically predisposed individuals, so tends to run in families. Typically symptoms occur through the teenage years and twenties and some people may “grow out” of it in their thirties, although this isn’t always the case (“late onset” hay fever can occur).
Impact on daily life
The UK has one of the highest prevalence rates of hay fever anywhere in the world, with the overall rate for the population being about 25 per cent rising to 38 per cent in teenagers. Although hay fever prevalence increased three fold between the 1960s and mid-1990s, the rate of increase has now slowed to less than one per cent per annum. The reasons for the high rates are unclear, but theories include frequent use of antibiotics for children in previous decades, air pollution, diet and the hygiene hypothesis.
Hay fever can have an adverse effect on a sufferer’s performance, education and career. It also has significant socio-economic impacts, too and, if left untreated, can develop into asthma. Paediatric allergists now recognise the combination of eczema and hay fever to be a significant marker, indicating an atopic child’s susceptibility to develop more serious allergic disease.
The main suspects
Plants with wind dispersed pollen, such as many trees, grasses and weeds, are the main culprits. These release vast amounts of pollen into the air to ensure widespread distribution. Grass pollen in particular is virtually ubiquitous in the summer months and it ranks as the top plant aeroallergen – not only in the UK, but Europe and most of North America.
In the UK about 95 per cent of hay fever sufferers are allergic to grass pollen, whereas only about 25 per cent have an allergy to tree pollens birch and oak and 20 per cent to weed pollen. People may also be allergic to fungal spores and react to the different types present in the air in vast numbers through the summer and autumn. The peak time is September and October when spores are released from mushrooms and toadstools. Oil seed rape pollen itself is rarely a problem in hay fever, but the crop gives off pungent chemicals (VOCs) which act as irritants to the mucous membranes and can cause itching, coughing and watery mucous production.
Different pollen seasons
The pollen seasons occur in succession from late winter through to the autumn. Although plants release their pollen in the same season every year, the exact timing can differ by many weeks, depending on the weather that year. A person may be allergic to one, several or, in some cases, many different types of pollen, which can lead to prolonged symptom stimulation lasting over several months. Keeping a diary of symptoms and comparing it with the pollen calendar can help in identifying the triggers.
Cross reactions occur between pollen from types of plant which are botanically related, such as alder, hazel and birch, so someone who has developed a birch pollen allergy will react to all of these, producing symptoms spasmodically through the spring. Cross reactions with foods can also occur. For example, people with birch pollen allergy may experience itching and swelling in the mouth when they eat raw apples and stoned fruits. This is known as Oral allergy syndrome and is caused by cross reacting antigens. The reaction does not occur if the fruits are cooked.
Hay fever sufferers differ in their sensitivity to pollen and an individual’s thresholds of response can vary with factors such as stress, hydration, pollution and time in the season. The amount of pollen in the air will differ a lot with many variables including weather and local vegetation. The Met Office runs a network of sites that monitor daily pollen counts and uses the data to produce pollen forecasts. These can help hay fever sufferers to plan their hay fever medication and activities. Pollen counts will be highest on dry, warm days with some wind as this type of weather is best for pollen release and dispersal. Wet weather will wash the pollen out of the air, reducing pollen levels.
Prevalence rates of hay fever in cities are typically as high or higher than in surrounding rural areas, even though pollen counts are generally lower. This apparent anomaly could be due to several factors. It is well known that air pollutants can enhance the impacts of air borne allergens through their effects on mucociliary clearance and the permeability of cell membranes. Also interactions between pollen and air pollutants can enhance the allergenicity of pollen grains. In addition, research has shown that living in the countryside, especially on farms with livestock, can be a protective factor against developing hay fever.
Overall this means that the severity of symptoms can differ a lot between individuals, on a daily basis, from location to location and even for one individual their reactions to the same amount of pollen can vary with time and place.
Hay fever diagnosis
The seasonality and patterns of symptoms in hay fever often allow self-diagnosis. However if someone is allergic to several types of pollen, symptoms may persist for several months, and allergy testing may be required.
Allergy skin prick testing is the most reliable way to confirm hay fever but in cases where this is best avoided eg: if the child has eczema or severe symptoms that mean they cannot stop taking antihistamines for the test, a blood test may be done. It is important that the results are interpreted accurately with knowledge of allergic diagnosis and symptomatic evidence, because false negatives can occur and sensitised people may be asymptomatic.There are a number of conditions that may present with symptoms of rhinitis, including vasomotor rhinitis, hormonal rhinitis infections and systemic disease. If symptoms are persistent and the cause unclear, secondary care referral is advised to an Ear, Nose and Throat department.
Reducing exposure to the allergens
The first line of defence is reducing exposure to the pollen and spores that trigger the reactions. This can be done in a number of ways as suggested on. Other self-help measures include getting adequate sleep, drinking plenty of water, reducing alcohol intake, avoiding stress if possible and having a healthy diet with a good supply of vitamin C. For those taking exams it is advisable for the school or college to be informed about the candidate’s hay fever and to ask that they are placed away from any open windows in the exam room. If underperformance is an issue, appeals may be made to some exam boards if supported by medical evidence of hay fever.
Pollen travels long distances and it is not possible to avoid it, but the amount of exposure can be minimised. If possible, sources of allergenic pollen should be reduced in the near vicinity of the sufferer’s home and school or college. For example at home, in school/college grounds and sports fields the grasses and weeds should be cut so they do not flower. If trees are planted they should be non allergenic types. Generally the insect pollinated types are best in this context.
Medications and treatments
Some children suffer from hay fever symptoms for years before being treated (if at all, in some cases). However, if a child does not begin to take medication until symptoms have started in the season, it will be more difficult to control them18. It is therefore important to be aware of what a patient is allergic to and commence medication before the trigger pollen is in the air. Several easily accessible guidelines are now available to support family health care professionals on allergic rhinitis and airway disease such as the ones from ARIA19 and BSACI20. Many people will self-treat with over the counter treatments and ENTUK21 have recently published a patient self-help guidance leaflet which is freely accessible.
Oral medication and anti-histamines
A wide range of suitable medications is available both over the counter and on prescription. Oral medication usually works within half an hour and therefore if symptoms are mild or come and go, this can be taken “as required” or daily, if needed. There are several types of antihistamine; the best known is Chlorphenamine (Piriton) which works well, but will cause drowsiness in most people. This side effect can be useful however when taken at night and can help children to sleep. Non sedating antihistamines such as Loratidine or Cetirizine, are advisable for those taking exams, etc. There are various brands of medication available and when one is not effective trying another is worthwhile.
To ensure patient compliance with continuous treatment regimes (such as steroid based nasal sprays, which do not work immediately), it is important for the patient to understand how a medication works. Often a person will abandon treatment altogether when medication does not reduce symptoms soon after it has been taken. Similarly it is important that steroid nasal sprays are applied correctly and at the right time in the season, ie: from about two weeks before the onset of symptoms.
Special case treatments
Steroid injection therapy is generally not recommended for hay fever sufferers, as this has severe side effects. However if a hay fever sufferer is facing an important life event, such as taking exams (or getting married when older), a short course of steroid tablets may be appropriately prescribed to support them on a short term basis.
In the cases of pregnant or breastfeeding women, a topical steroid nasal spray is the recommended treatment of choice. Use of antihistamine tablets is not advised except in special cases. Alternatively certain non-medicated therapies may also be of benefit, particularly those that act as filters or as barriers to airborne allergens. There is clinical evidence that this treatment type is effective in reducing symptoms without adverse effects.
Various non-medicated treatments are available, including homeopathic ones, herbal remedies, nasal creams, douches and powder sprays but clinical evidence is sparse. One exception is Care Allergy Defence in which over 11 clinical studies conducted in four countries have shown its effectiveness in blocking allergens and working as a barrier inside the nose. This inert powder is a welcome addition to treatments available and can be particularly useful when medicated treatment is not desired, such as for some young children. Care Allergy defence can be used in children and infants from 18 months old.
Disease altering immunotherapy
Immunotherapy or ‘desensitisation’ may be a possibility for patients with severe hay fever symptoms that cannot be controlled by symptomatic medications.
Patients may be referred to an Allergy Specialist Centre for treatment by a series of injections (subcutaneous immunotherapy), or by daily medication under the tongue (sublingual immunotherapy) in increasing quantities. One of the latest approaches is Grazax grass pollen sublingual immunotherapy tablet for adults and children older than five years.
As hay fever rates are highest in young people, it is important that symptoms are recognised so treatment can be given early. This is vital as – if left untreated – it can develop into asthma. It is advisable for all hay fever sufferers, especially children, to have a yearly review. This review should include growth assessment where steroid treatments are used regularly. A review before the pollen season starts will also allow time to provide early, and therefore more effective, advice, prescriptions and support management.