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Global warming and hay fever in Ireland

Dr Ranbir Kaulsay gives a comprehensive update on the management of allergic rhinitis

This article’s headline certainly sounds like a medical apocalypse indeed. But it is an undeniable fact that climate change and global warming are a reality.

The impact of such a change is wide and far-reaching and has even had an impact on our weather patterns. As far as Ireland is concerned, we have experienced milder winters and very pleasant summers over the last few years with some countries experiencing an increase in more extreme natural phenomena such as flooding unfortunately. Generally though it has resulted in much more pleasant weather in Ireland.

However, we have had some bizarre and unusual changes in our predicted weather patterns and these in turn have caused some differences in our flora and fauna. So all is not rosy, as we have seen a marked increase in CO2 temperature, which has led to a much longer and more intense pollen season.

There has also been a marked increase in temperature recently which has caused high levels of tree pollen to surge, and this has caused what is known as a ‘pollen bomb’ effect to occur. Dangerous increases in pollen levels have been noted to cause a lot of health concerns especially in patients who are asthmatic. Unfortunately, up to 80 per cent of patients with asthma also have coexisting hay fever and this may have detrimental effects on their health with sudden reductions in their lung function and an increase in bronchial hyper-responsiveness. This was recently seen in Melbourne, Australia, in November 2016 where an extreme weather event caused a spike in pollen which coincided with a thunderstorm that caused 35 patients to be admitted to intensive care units, 10 of whom died with previously undetected bronchial hyper responsiveness.

Ireland, our CO2 and pollen problem

Increased carbon dioxide levels, which are found to be higher in urban rather than rural areas, also cause pollen to increase in areas where there shouldn’t be too high tree or grass pollen levels such as in cities. As we are all aware, CO2 levels continue to rise, especially in our cities, which is why there has been a global effort to try to reduce climate change.

In a recent article in the Irish Independent, it was pointed out that Ireland faces fines of €600m a year from the EU for failing to meet renewable energy targets and cutting carbon emissions by 2020.

Irish EU Commissioner Phil Hogan said there was confusion in some quarters that the 2020 targets under the EU Renewable Energy Directive would be merged into the more ambitious targets for 2030. This would give the Government some breathing space and lessen the risk of punitive fines.

“But that is not the case. The 2020 target must be adhered to,” Mr Hogan said.

The Commissioner urged the Government to be more proactive in developing wind and wave energy and reduce dependence on fossil fuels in line with EU agreed targets.

Nonetheless, an increase in CO2 in general would be bad news for both the climate and will lead to an increase in our already increasing trend of hay fever.

Alan O’Reilly of Carlow Weather recently explained why pollen is on the rise, saying: “With high temperatures coming for the next few days the pollen will open up very quickly on the trees.

“Because it has been so wet people probably haven’t been suffering. But the increase in temperatures will bring with it a sudden increase in pollen.

“Rain was keeping the pollen at bay, but with the dry, hot, sunny weather the trees will expose a lot more pollen. So, there will be a lot of pollen in the area for the next few days” (May 2019).

However, with the milder winter months just gone by, tree pollen started to pollinate early this year, with some patients already noted with tree pollen allergy in my clinics earlier than we would usually see them traditionally.

Useful tips for your patients from the Asthma Society of Ireland on how to survive hay fever season:

Talk to a doctor or pharmacist about taking medication to prevent/reduce symptoms. Don’t wait until you feel unwell.

Keep an eye daily on our pollen tracker on asthma.ie.

Keep windows closed in your bedroom at night.

Keep windows and doors closed when the pollen count is high.

Stay indoors as much as possible on high pollen days.

Stay away from grassy areas, especially when grass is freshly cut.

Put Vaseline around your nostrils to trap pollen.

Wear wraparound sunglasses to stop pollen getting into your eyes.

Shower, wash your hair and change your clothes if you have been outside for an extended period.

Avoid drying clothes outdoors, or shake them outdoors before bringing them in.

Minimise your contact with pets who have been outdoors and are likely to be carrying pollen.

Consider a purifier with a built-in air quality sensor to remove allergens and pollutants from the air.

These are the usual tips that one would receive about practical suggestions, but very few of these work with a significant effect, especially during times of high pollen surges or high pollen seasons. It is imperative to plan ahead of time for patients who know that they suffer from hay fever so that optimum control can be attained early and well – especially for children and young adults sitting important exams during the summer months like the Junior Cert and Leaving Cert, not to mention all other summer university final examinations. An international study has shown that school children who suffer from hay fever are more likely to experience a noticeable drop in exam performance (ISAC study 1995/2007).

Unfortunately, it has been shown that most patients are unsatisfied with their current control of allergic rhinitis and many patients find themselves on multiple medications to control the disease process. It was found that the most common medications used were a combination of antihistamines and intranasal corticosteroids, still with less than adequate control.

Current guidelines for the treatment of allergic rhinitis based on the latest ARIA (Allergic Rhinitis and its Impact on Asthma) criteria place intranasal corticosteroids as the first line of therapy for the treatment of the disease. Second generation antihistamines may be required as may ocular mast cell stabilisers (chromone medications). New combination intranasal antihistamine/corticosteroid sprays have proven effective in moderate to severe allergic rhinitis and several studies including a recent local study have found these an effective treatment.

Diagnosis of allergy

The definitive evidence of allergy, after appropriate history and examination, should be attained by either specific IgE measurements or by skin prick testing. There is little value of total IgE measurements and no role for non-medical tests such as kinesiology, VEGA testing or food intolerance testing for rhinitis.

Medical care

The management of allergic rhinitis consists of four major categories of treatment, (1) environmental control measures and allergen avoidance, (2) pharmacological management, (3) immunotherapy, and (4) surgery.

Environmental control measures and allergen avoidance involve both the avoidance of known allergens (substances to which the patient has IgE-mediated hypersensitivity) and avoidance of non-specific, or irritant, triggers. Consider environmental control measures, when practical, in all cases of allergic rhinitis. This reinforces the need for proper and accurate allergy testing.

Pollens and outdoor moulds

Because of their widespread presence in the outdoor air, pollens can be difficult to avoid. Reduction of outdoor exposure during the season in which a particular type of pollen is present can be somewhat helpful. However, it is not ideal to restrict the movement of patients when the weather becomes better, nor is it possible in most cases.

In general, tree pollens are present in the spring, grass pollens from the late spring through summer (April to August), and weed pollens from late summer through autumn, but exceptions to these seasonal patterns exist. Particular area-specific pollens such as ragweed and rapeseed may also be of importance in certain parts of Ireland. Certain pollen counts tend to be higher on dry, sunny, windy days.

Outdoor exposure can be limited during this time, but this may not be reliable because pollen counts can also be influenced by a number of other factors. Keeping the windows and doors of the house and car closed as much as possible during the pollen season (with air conditioning, if necessary, on recirculation mode) can be helpful. Taking a shower after outdoor exposure can be helpful by removing pollen that is stuck to the hair and skin.

Despite these measures, patients who are allergic to pollens usually continue to be symptomatic during the pollen season and usually require some other form of management. As with pollens, avoidance of outdoor/seasonal moulds may be difficult. Symptomatic therapy with newer generation antihistamines, nasal corticosteroids and ideally immunotherapy for more severe cases may be necessary.

Indoor allergens

Depending on the allergen, environmental control measures for indoor allergens can be quite helpful. House dust mites are the most common cause of rhinitis throughout the world and this is also the case in Ireland where they are perennial allergens, however, they do tend to peak during the cooler months, when the windows are closed, and the central heating is on. This also coincides with a spike in rhinitis and asthma during the cooler months.

Covering the mattress and pillows with impermeable covers helps reduce exposure to dust mites. Bed linens should be washed every two weeks in hot water (60-90  ̊C) to kill any mites present. Thorough and efficient vacuum cleaning of carpets and rugs with a HEPA based vacuum can help, but, ideally, carpeting should be removed especially in the bedroom. The carpet can be treated with one of several chemical agents that kill the mites or denature the protein, but the efficacy of these agents  does not appear to be dramatic.

Dust mites thrive when indoor humidity is above 50 per cent, so dehumidification is helpful, or better still opening the windows as much as possible. Indoor environmental control measures for mould allergy focus on reduction of excessive humidity. The environmental control measures for dust mites can also help reduce mould spores.

For animal allergy, depending on the strength of the allergy, complete avoidance is the best option. For patients who cannot or do not wish to avoid the pet, confinement of the animal in a non-carpeted room may be beneficial except for large animals where pre-dosing with antihistamines may be required for occasional contact, eg, horseriding classes, etc.

Washing a dog or cat with anti-allergy shampoo can help greatly. In all cases, immunotherapy is also available in respect to occupational allergy to animals, but this is normally restricted to occupational pet exposure due to costs (eg, veterinarians, jockeys).

Non-specific triggers

Exposure to smoke, strong perfumes and scents, fumes, rapid changes in temperature (vasomotor rhinitis), and outdoor pollution can be non-specific triggers in patients with allergic rhinitis. Consider avoidance of these situations or triggers if they seem to aggravate symptoms.

Treatment

Antihistamines are the first line of treatment for most allergy symptoms and these medications have been in existence for over 60 years but have evolved slowly.

Older antihistamines such as chlorphenamine have significant side effects such as drowsiness and also have strong anti-cholinergic effects, eg, dry mouth, etc, and unfortunately these are still being used as first-line antihistamines today.

Loratadine, cetirizine and fexofenadine are newer antihistamines and these have evolved into levocetirizine and desloratadine, which are more effective and have fewer side effects. These preparations are available over-the-counter in some pharmacies with fexofenadine still needing a prescription.

One of the best and my personal new favourite is bilastine, because of its effectiveness, safety and non-drowsy property. As this is one of the newest antihistamines, it is still available only on prescription but is highly effective.

Nasal sprays

These nasal sprays remain the main treatments for rhinitis and are divided into:

1) Decongestant sprays – very effective over-the-counter medications but should never be used for more than five days continuously.

2) Intranasal corticosteroids – very effective in treating all the symptoms of rhinitis and can be used safely for prolonged treatment regimes.

3) Nasal saline washes and moisturisers – effective in washing out mucus and allergens and should be recommended.

4) Newer combination antihistamines and steroid therapy – extremely effective preparation available on prescription (Dymista) and has been proven to be effective for all types of rhinitis.

Intranasal ultraviolet phototherapy

The diagnosis and treatment of rhinitis has evolved and has improved the quality-of-life for our patients and their families, with a wide variety of options now available.

Rhinolight is a new and very impressive non-interventional and non-pharmacological treatment of rhinitis. This involves using set and safe ultraviolet lights that are administered into the nostrils for three minutes each time for up to six-to-eight sessions.

This is only done by trained medical personnel and reduces the mucus and allergy cells within the nostrils.

Effective, safe and a new treatment option for our patients. www.rhinolight.eu.

Immunotherapy (desensitisation)

Injectable

A considerable body of clinical research has established the effectiveness of high-dose allergy subcutaneous injections in reducing symptoms and medication requirements. Success rates have been demonstrated to be as high as 80-90 per cent for certain allergens. It is a long-term process; noticeable improvement is often not observed for six-12 months, and, if helpful, therapy should be continued for three years.

Injectable immunotherapy is not without risk because severe systemic allergic reactions can sometimes occur. For these reasons, carefully consider the risks and benefits of immunotherapy in each patient and weigh the risks and benefits of immunotherapy against the risks and benefits of the other management options.

Indications: Immunotherapy may be considered more strongly with severe disease, poor response to other management options, and the presence of comorbid conditions or complications. Immunotherapy is often combined with pharmacotherapy and environmental control.

Administration: Administer immunotherapy with allergens to which the patient is known to be sensitive and that are present in the patient’s environment (and cannot be easily avoided). The value of immunotherapy for pollens, dust mites, and cats is well established. The value of immunotherapy for dogs and mould is less well established.

Contraindication: Several potential contraindications to immunotherapy exist and need to be considered. Immunotherapy should only be performed by individuals who have been appropriately trained, who institute appropriate precautions, and who are equipped for potential adverse events. This route is still used extensively in the US and in other parts of Europe. In my allergy practices I use mostly sublingual immunotherapy.

Sublingual

Sublingual immunotherapy (SLIT) is currently increasing in use, particularly in Europe because of its safety and efficacy and the fact that it is licenced and reimbursable for some patients.

We have had two sublingual immunotherapy treatments for grass pollen registered and available to us (by GMS and on the Drugs Payment Scheme) since 2008.

Oralair (five-grass pollen extract) and Grazax (Timothy grass extract) have been used by me for patients with severe grass pollen allergy where standard antihistamine and other medicines fail to provide relief. We have many patients on or having completed three years of treatment.

It is then effective in dampening hay fever for at least five years after completion of treatment and as such may be considered to have a disease-modifying effect.

Sublingual immunotherapy for house dust mite allergy has been available and used for many years on an unlicensed ‘named patient basis’. This has been used in liquid form as sublingual drops with good efficacy and safety, and the greatly anticipated tablet form of this treatment has recently been made available by a number of European allergy companies. One in particular has been manufactured and heavily researched for many years by the same company that makes Grazax and this is known as Acarizax. This tablet is composed of standardised extracts of the two most common species of dust mites, namely Dermatophagoides pteronyssinus and D farina and is indicated for allergic rhinitis and allergic asthma due to house dust mite. It has also had a significant positive effect in reducing asthma exacerbations in patients with allergic asthma treated by this sublingual tablet. Hopefully this treatment will be registered by the HPRA and become available on the Drug Payment Scheme and GMS soon.

Surgery

For some patients with recurrent sinusitis, nasal polyposis, septal deviation or refractory allergic rhinitis, nasal surgery will be necessary. Turbinoplasty or radiofrequency turbinoplasty may be the surgical procedure of choice to improve nasal congestion, and to improve ongoing symptoms of allergic rhinitis with or without intranasal medicated sprays and pharmacotherapy.

Nonetheless, control of rhinitis and allergies in general has improved significantly in recent years with many safe and effective treatments and options now available to our patients, young or old.

For more information go to www.dublinallergy.com.

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