Allergic Rhinitis: under treated and under diagnosed
Allergy Ireland's Dr Iseult Sheehan features in the Irish Medical Times in May 2021.
Allergic rhinitis (AR) is often considered to be an annoyance rather than a serious condition. However it has been shown to have a significant impact on quality of life. The burden of this disease is consistently underestimated with patients being under-diagnosed and under-treated. It can be considerably debilitating for some, affecting sleep and functional capability, including cognitive and psychomotor function. This can result in reduced ability to work or attend school, and to participate in social activities or sports.
The economic impact is striking. An Australian study in 2007 showed their economy lost approximately $5.6 billion that year due to reduced productivity as a result of allergic disease.(1)
The impact on a child’s education is worrying. This becomes particularly apparent during hay fever season which coincides with exam time. A UK study of teenagers with seasonal AR found that there was a reduction in exam performance. (2) This is most relevant for Leaving Certificate students and those in University.
It is estimated that AR affects at least 400 million people worldwide and the prevalence within Europe is between 17 and 29%. The UK has a prevalence of 26% and Ireland is likely to be similar to this. (3)
What is most concerning is that the prevalence of AR is increasing globally. This was corroborated by the ISAAC study (2006) which found an increase in prevalence of AR from 13% to 19% over an 8-year period in a cohort of 13-14 year olds.(4) A smaller study in Cork demonstrated an increase in prevalence from 7.6% to 10.6% over a 5-year period in a cohort of 6-9yr olds.(5) This illustrates the necessity to correctly diagnose and manage this chronic condition.
Symptoms of Allergic Rhinitis
AR is an IgE mediated inflammatory reaction following exposure to an allergen. This results in inflammation of the nasal lining and/or conjunctiva. The symptoms characteristically include rhinorrhoea, nasal obstruction, sneezing and nasal itching. Additionally symptoms will often include an itchy throat, irritated watery itchy eyes with associated periocular oedema, or dark rings under the eyes. Patients can experience fatigue, snoring, mouth breathing and a feeling of heaviness in the head or a ‘fuzzy’ head. If the sinuses are affected the patient may experience sinus pressure and headaches, and a post nasal drip. Compression of the olfactory nerve due to oedema within the nasal cavity can result in an altered sense of smell and/or taste.
One airway, one disease
AR is also a risk factor for asthma. In fact 90% of asthmatics have AR, and 30-40% of those with AR have asthma. A ‘united airways’ disease approach to management is the more favoured approach in recent years. Moreover, the treatment of nasal inflammation in asthmatics has been shown to improve outcomes. This highlights the importance of assessing for both asthma and rhinitis in these patients.
AR can also be associated with comorbid dermatological conditions such as atopic dermatitis, urticaria and pruritis upon exposure to an allergen.
Classification and Diagnosis
Rhinitis can be classified as either allergic or non-allergic. AR is predominant but both can often co-exist.
Allergic Rhinitis can be divided into seasonal and perennial based on allergen triggers. Seasonal rhinitis includes sensitisation to grass pollen, tree pollen or fungal spores. Whereas perennial rhinitis is commonly triggered by house dust mite or animal dander. This classification system is effective at giving a likely diagnosis of the trigger which assists with recommending appropriate avoidance measures.
However, a new classification system focusing on the functional ability of the patient, including the frequency and severity of symptoms, has become a much more effective tool for making treatment decisions. This was developed by Allergic Rhinitis and the Impact on Asthma (ARIA) guideline in collaboration with the World Health Organization.(6)
The diagnosis of AR is clinical. However skin prick allergy testing or specific IgE blood testing will confirm the allergen trigger. It is vital to examine the nose whereby you will often see bulky oedematous turbinates with visible increased mucus production. Pallor of the mucosal lining is often present, particularly in long-standing cases. Occasionally the mucosa will lose its smooth appearance and instead will have ridges and pitting from chronic allergic challenge. Pre-polypoid tissue will occasionally be present.
Allergen avoidance should be discussed. Nevertheless avoidance alone is generally not enough to manage symptoms unless the allergen trigger is dander, for example, and the offending animal can be removed from the home.
Smoking cessation should be advised always. Smoking can be associated with chronic nasal symptoms and may even be associated with the development of polyposis. Passive smoking or ‘vaping’ appear to carry similar risk.
Saline irrigation is an effective way to directly cleanse the nasal cavity with the resultant reduction of mucus, inflammatory mediators and bacterial burden. It has also been shown to improve mucociliary function.
In patients with mild intermittent symptoms an antihistamine is often effective. Second generation antihistamines are recommended, as they carry less cholinergic and sedating side-effects. Oral or nasal decongestants can be used as a rescue medication, but for no longer than five days to avoid rebound symptoms.
The ARIA guideline – which was most recently updated in 2019 – recommends intranasal corticosteroids as the first-line treatment for moderate-severe, intermittent or persistent AR.6,7 A low bioavailability is recommended and so newer generation intranasal corticosteroids are preferred. If the nasal cavity is very obstructed, a nasal spray may not be effective until the oedema has been reduced using intranasal corticosteroid drops. Should this not be effective, a combination intranasal treatment is now available combining corticosteroid and antihistamine.
Eye symptoms can be managed conservatively with cold compresses and tear supplements. However, if these symptoms persist, it is advisable to consider oral and topical antihistamines, topical mast cell stabilizers (sodium cromoglicate) or decongestants. Topical corticosteroids should ideally be prescribed under the care of an ophthalmologist.
If there is evidence of lower airway irritability or asthma, a leukotriene receptor antagonist can be trialled. In severe cases, short bursts of oral corticosteroids are occasionally required.
Unfortunately adherence to treatment remains a major issue for those with AR and asthma. Mobile Airways Sentinel Network (MASK) recently established that having a patient-centred approach to management was much more likely to improve adherence in this cohort. This approach during a consultation is very effective, but the use of mobile technology will likely prove useful in the future.
Immunotherapy has been shown to significantly reduce symptoms and medication requirements, and is recommended by the ARIA guideline. Additionally, the Global Initiative for Asthma (GINA) 2020 guideline recommends immunotherapy be considered for asthmatics sensitised to dust mite.10
Immunotherapy involves exposing a patient to minute quantities of the allergen trigger allowing the immune system to build up a resistance. It is essentially like a vaccination.
It can be given as a subcutaneous injection or as a sublingual tablet. Sublingual therapy is used predominantly in Ireland, and is currently available for grass pollen, dust mite and tree pollen. Compliance is crucial and regular follow-up advised. It is usually a three-year process whereby the patient takes it daily. It is highly effective and well-tolerated.
Phototherapy is well established for skin conditions and is now being used within the nasal cavity to manage AR. It uses UV-A (25 per cent), UV-B (< 5 per cent) and visible light (70 per cent) to induce a local immunosuppressive effect by inhibiting allergen induced histamine release from mast cells and inducing apoptosis of T lymphocytes and Eosinophils.
It essentially reduces allergy cells within the nasal cavity thus reducing symptoms. It is particularly useful when pharmacological treatment is insufficient or contraindicated.
Dr Iseult Sheehan
Clinical Director, Allergy Ireland,
MICGP, FRACGP, MB BAO, BCh, LRCP&SI, BA (Hons) Biochemistry and Immunology
- Access Economics. The economic impact of allergic disease in Australia: not to be sneezed at. Sydney: Access Economics; 2007. Available at www.allergy.org.au/content/view/327/274/.
- Walker S, Khan-Wasti S, Fletcher M, Cullinan P, Harris J, Sheikh A. Seasonal allergic rhinitis is associated with a detrimental effect on examination performance in United Kingdom teenagers: case-control study. J Allergy Clin Immunol 2007; 120(2): 381-7.
- Bauchau V, Durham SR. Prevalence and rate of diagnosis of allergic rhinitis in Europe. European Respiratory Journal 2004; 24(5): 758.
- Asher MI, Montefort S, Björkstén B, et al. Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multicountry cross-sectional surveys. Lancet 2006; 368(9537): 733-43.
- Duggan EM, Sturley J, Fitzgerald AP, Perry IJ, Hourihane JO. The 2002-2007 trends of prevalence of asthma, allergic rhinitis and eczema in Irish schoolchildren. Pediatr Allergy Immunol 2012; 23(5): 464-71.
- Bousquet J, Schünemann HJ, Togias A, et al. Next-generation Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines for allergic rhinitis based on Grading of Recommendations Assessment, Development and Evaluation (GRADE) and real-world evidence. J Allergy Clin Immunol 2020; 145(1): 70-80.e3.
- Klimek L, Bachert C, Pfaar O, et al. ARIA guideline 2019: treatment of allergic rhinitis in the German health system. Allergo Journal International 2019; 28(7): 255-76.
- Bjermer L, Westman M, Holmström M, Wickman MC. The complex pathophysiology of allergic rhinitis: scientific rationale for the development of an alternative treatment option. Allergy Asthma Clin Immunol 2019; 15: 24.
- Bousquet J, Bedbrook A, Czarlewski W, et al. Guidance to 2018 good practice: ARIA digitally-enabled, integrated, person-centred care for rhinitis and asthma. Clin Transl Allergy 2019; 9: 16.
- Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention. Updated 2020. Available at: https://ginasthma.org/. [Last accessed on 3rd January 2021].