Seasonal allergic rhinitis in focus

The UK currently holds the dubious honour of being joint top in the global allergy polls for the highest incidence of hay fever.¹ Cases in the UK have trebled over the last 20 years, with around 10-15% of children and a quarter of all adults in the country now affected by this seasonal allergic rhinitis.²

Pollen prevalence

Traditionally, the main hay fever season in the UK is considered to run from May to September, peaking around June/July due to an abundance of grass pollen. However, climate change is starting to shift this typical seasonal picture. Several species of plant are now blooming earlier and for longer due to higher average temperatures throughout the year. This has the dual effect of increasing pollen levels in the air and extending how long the pollen season lasts.³

Birch pollen is the major tree pollen found in Northern and Central Europe and is a leading cause of hay fever in the UK.² However, grass pollen is the most common hay fever trigger overall which explains the traditional peak in symptoms during the summer months.²

Throughout the pollen season, different types of allergen dominate at different times:

• Pollen from trees such as elder, elm, hazel and especially birch appears first – from as early as February/March through to May
• Grass pollen occurs from May until July/August
• Weed and nettle pollen can be produced at any time of the year, but are more common later in the hay fever season, from the end of June until September
• Mould fungus can cause hay fever symptoms all year round.

The pollen count is also influenced by geographical location. Hay fever sufferers residing in the north of the UK may be heartened to know that their pollen season is typically shorter and starts later than in the south of the country. As would be expected, pollen levels also tend to be lower in urban and costal areas compared to rural and inland locations.²

Symptom spectrum

In hay fever sufferers, the immune system overreacts to inhaled pollen – a fine, lightweight powder produced by plants – triggering a range of irritant and inflammatory signs and symptoms. While sneezing and a runny nose are the hallmarks, other common hay fever features include:

• Nose bleeds and congestion
• Red, watering, itchy or gritty eyes
• Swollen eyelids
• Itchy nose, throat and/or ears
• Headache
• Tiredness
• Coughing
• Loss of taste or smell

Sensitivity to light may also be a problem for people who develop allergic conjunctivitis. Those with other atopic and allergic conditions like eczema and asthma are more likely to suffer from hay fever.² This is known as the allergic triad.

Prolonged hay fever also increases the sensitivity of the mucous membranes lining the airways, making sufferers more susceptible to general airborne irritants (e.g. dust, cigarette smoke), meaning they may also develop other conditions, such as sinusitis.³

OTC intervention

The immune system reacts to the presence of pollen by releasing histamine, which is a key driver of hay fever symptoms. Antihistamines are therefore the mainstay of hay fever treatment.

A wide variety of antihistamine-based hay fever treatments and formats are available to purchase OTC including tablets, capsules, liquids, syrups, creams, lotions, gels, eye drops and nasal sprays.

The non-sedating antihistamines such as acrivastine, cetirizine, fexofenadine and loratadine are generally preferred to the older group (e.g. chlorphenamine, cinnarizine, diphenhydramine, hydroxyzine and promethazine) which can cause drowsiness. As these also have a longer duration of action, it means they can be taken less frequently, which is more convenient.¹

Intranasal corticosteroids are the most effective treatment available OTC for managing nasal congestion in people with hay fever.^4,5 Options include intranasal mometasone, fluticasone, mometasone and triamcinolone, all of which show minimal systemic absorption.

These agents work by 'dampening down' the local immune reaction in the nose, thereby reducing inflammation, swelling and mucus production in the nasal passages, relieving associated symptoms of congestion, sneezing and itching. However, steroid nose sprays can take several weeks to reach full therapeutic efficacy and it is useful to advise patients to persist with treatment during this time.

Mast cell stabilisers are another class of OTC hay fever treatment. They work by inhibiting the degranulation of mast cells, thereby blocking the release of histamine and other inflammatory mediators. As they are particularly effective against occular symptoms, they are typically formulated as eye drops — the most common ingredient is sodium cromoglicate, which is found in a range of different OTC brands. These drops should be applied up to four times daily and are suitable for children aged 6 years and above.

People particularly troubled by nasal stuffiness (caused by allergen-induced inflammation of the blood vessels lining the nose) may benefit from treatment with nasal decongestants, such as oxymetazoline or xylometazoline. These work by shrinking blood vessels in the nasal passages, but they should only be used for short periods of time due to the risk of rebound congestion.

Pharmacists should also be familiar with the increasing number of combination allergy and hay fever products available OTC which contain more than one active ingredients. For example, nasal sprays containing both a corticosteroid and an antihistamine are available, as are eye drops containing topical antihistamine and decongestant.

Referral 

If the patient advises you that the first-line product has been ineffective, you will first need to find out if there is an obvious underlying reason for the treatment failure.

Reasons may include non-adherence (i.e. if the person has not used the product at the recommended dose, frequency, or duration) or incorrect technique when using intranasal sprays or eye drops. In some cases, it may be appropriate to consider stepping up treatment by adding an agent with an additional/alternative mode of action or using a combination product.

If appropriate, pharmacists could also advise customers to continue using their current treatment(s) over longer periods of time (e.g. an antihistamine tablet daily) rather than relying on ad hoc use.

Ultimately, customers with severe hay fever symptoms or those who have found OTC products ineffective may require onward referral for more effective prescription-only medication, or to explore potential immunotherapy.

Referral should also be recommended for people if hay fever is having an adverse negative impact on their daily life, sleep or work performance, despite optimum OTC treatment. Patients with symptoms suggestive of other potential underlying respiratory conditions, such as wheezing, shortness of breath, and chest tightness should also be advised to consult their GP.

Allergen avoidance

The pollen count is a measurement of the concentration of pollen in the air and is the average number of pollen grains per cubic meter observed over a 24-hour period.² Pollen levels usually rise in the early morning, peaking mid-afternoon or early evening.

Advising patients to check the pollen count daily is key advice for hay fever sufferers as the pollen count can be influenced by many meteorological factors including temperature, rain and wind. Rainfall generally causes a drop in pollen concentrations while high temperatures (above 28°C) reduce levels of all pollen.

Light winds may mean pollen struggles to become airborne while heavy winds can help to disperse it and thin out the concentration in the air. As plants need sunlight for photosynthesis, pollen production is also generally lower on cloudy days.² Warm, sunny days with a gentle breeze are optimal conditions for creating a high pollen count, increasing the risk of developing hay fever symptoms.

Advice on allergen avoidance techniques is central to the effective management of hay fever and should be provided to all affected customers alongside OTC treatment recommendations. NICE CKS and the NHS specifically advise that people with hay fever take the following preventative steps when pollen count is high:^4,6

• Limit time outdoors if possible
• Avoid grassy, open spaces, particularly during the early morning, early evening, and during mowing
• Avoid drying washing outdoors
• Keep windows and doors shut in cars and buildings as much as possible
• Shower and wash hair when returning from outside to wash off the pollen
• Change clothes or remove/shake outdoor clothing before coming indoors
• Wear sunglasses (ideally wraparound)
• Use nasal barriers — for example, masks covering the nose and mouth or commercially available powders, balms or creams applied to the nose
• Vacuum regularly and dust with a damp cloth to remove pollen from inside the home
• Try using a pollen filter for the car or a HEPA filter for the vacuum cleaner
• Avoid keeping fresh cut flowers in the house
• Limit pets from entering the home if possible as pollen can be carried on their fur.

Lifestyle factors such as alcohol consumption can also worsen the effects of hay fever, as can smoking which exacerbates symptoms.

Treatment choices

Hay fever is often overlooked as a minor condition, but the symptoms can have a significant negative impact on quality of life. In severe cases, hay fever can disrupt sleep, impair daytime concentration, and lead to missed days of work or school.²

When it comes to providing advice around OTC hay fever treatment options, it is important for pharmacy staff to consider both patient preference and prior treatment history. Many patients opt for antihistamines because they have a fast onset of action and can be taken when symptoms become problematic, rather than on a continuous daily basis.

Alternatively, antihistamines can be taken throughout the pollen season if preferred to keep symptoms dampened down, rather than opting for an on-demand approach.⁵

Non-sedating antihistamines tend to be favoured as they allow customers to continue their daily activities (e.g. driving) without worrying about potential drowsiness.

When it comes to timing, it is best for patients to start treatment with nasal corticosteroid sprays before the hay fever season begins for optimal results. They should then be used daily, irrespective of symptoms. It should be noted that corticosteroid nose sprays are only suitable for those aged over 18 years.

Similarly, it can take between a few days to a week for mast cell stabilisers to get to take effect, so it is best to use anti-allergy eye drops regularly throughout the pollen season rather than using them occasionally to treat acute symptoms.

Specific patient groups

Older adults with hay fever require careful consideration due to the likelihood of comorbidities and the potential for drug-drug interactions. They may also be more at risk from the potential side effects of hay fever medications, particularly the drowsiness that can be caused by first-generation antihistamines, which can increase the risk of falls.

Patients with hay fever and asthma are another important group for pharmacists to prioritise. Over time, hay fever symptoms that affect the upper respiratory passages may impact the lungs, leading to the development of allergic asthma.³ Hay fever is now recognised as a key risk factor for the development of asthma, which further underscores the importance of effective treatment.²

For people with allergic rhinitis with coexisting asthma, the reaction to pollen worsens swelling and irritation in the airways, which can in turn exacerbate symptoms such as wheezing, coughing and breathlessness.

Sobering figures from UK for 2014 indicate that in around 15% of asthma deaths hay fever was a contributory factor.¹ And, according to Allergy UK, 80% of asthma patients will also suffer from hay fever. So while this is an important patient group to consider anyway in pharmacy, you should be particularly alert for exacerbation of asthma symptoms during the hay fever season.