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Allergic rhinitis: do you know your trees from your weeds?

Jan Chantrell
RGN BSc
Allergy Module Leader
Education for Health

Respiratory Nurse Specialist for Asthma and Allergy
University Hospital of Leicester

How do you feel when you get a common cold? Do you suffer from sneezing, a runny and/or blocked nose, itchy eyes, headaches, fatigue and poor productivity at work? You certainly won't feel like going down to the pub at night. Imagine feeling like that for three months let alone three days, and this is what it is like to have allergic rhinitis.
A common cold is a form of rhinitis and a useful tool when trying to imagine what it must feel like to suffer from allergic seasonal rhinitis. Allergic rhinitis is often trivialised by healthcare professionals even though symptoms have been shown to reduce concentration, productivity and to even cause a drop in GCSE grade between mock and final exams.(1)
Allergic rhinitis is suggested to affect up to 20% of the adult population.(2) Symptoms include sneezing, rhinorrhoea, nasal blockage and itching. These occur for at least an hour each day.(3) Patients may also have secondary symptoms of headache and sleep deprivation leading to fatigue and irritability as well as ocular, throat and inner ear symptoms. These symptoms are the result of an exaggerated immunoglobulin E (IgE)-mediated response following exposure to an allergen in the nose.

Mechanisms of allergy - IgE in the nose
Allergic reactions such as seasonal rhinitis are a classic example of type 1 hypersensitivity.(4) Type 1 hypersensitivity describes an immediate reaction (normally within 15 minutes) between a specific allergen, eg, grass pollen, and immune cells, eg, mast cells. If a patient is sensitised to an allergen such as grass pollen, the body produces IgE specific to that allergen. These IgE attach to mast cells (which circulate in the body just under the skin and in the mucosa of the eye, nose and lungs) by means of receptors on the cells' surface. This is known as sensitisation or atopy. At this stage, the patient will have no symptoms and no knowledge that anything has taken place in their body. However, after further exposure to the allergen, such as during the following pollen season, the allergen is breathed into the nose or lungs and bridges across two IgE attached to mast cells. The bridging of the IgE causes the mast cell to degranulate or break down, resulting in the release of chemicals including histamines, prostaglandins, tryptases and leukotrienes. These chemicals cause itching due to irritation of nerve endings, redness due to vasodilation of blood vessels, and swelling due to increased vascular permeability. Such reactions give rise to nasal itch, sneezing, rhinorrhoea and blockage symptoms in allergic rhinitis and wheeze, shortness of breath, cough and a tight chest symptoms in seasonal allergic asthma.
Symptoms and the classic time course (15 minutes after exposure) mark the cornerstone of allergy diagnosis, and, at a simplistic level, allow the health professional to quickly differentiate between allergic and nonallergic symptoms. 

Diagnosis of allergic rhinitis
The most important aspect of clinical allergic rhinitis is taking the patient's history. Often investigations such as skin prick testing or specific IgE (previously known as RAST) are not required unless further treatments such as subcutaneous or sublingual immunotherapy are needed. Detailed questioning of when the symptoms start and finish, and knowledge of what pollens are around at that time of year will guide your diagnosis (see Table 1).

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It is important to know when the pollen seasons start in your area, as they differs around the UK. In the midlands, the grass pollen season starts usually at the end of May or the first week of June. However, if you live in Cornwall this could be two weeks earlier and in Scotland two weeks later. 

History taking
The questions you need to ask to obtain a diagnosis are very similar to those you may ask in an asthma clinic. You should examine a patient's:

  • Past medical history.
  • Family history.
  • Symptoms (sneezing, itch, blockage, rhinorrhoea or associated eye symptoms).
  • Secondary symptoms, eg, headache, fatigue.
  • Seasonal variation in symptoms.
  • Symptom severity.
  • Medication history - did they improve their symptoms? (If not - it is vital to check concordance and technique with nasal sprays).
  • Trigger factors.
  • Occupation and hobbies.

If the patient's history clearly leads you to a diagnosis of seasonal allergic rhinitis, then there is no need to perform any further investigations, eg, skin prick testing or specific IgE. The mainstays of treatment for seasonal allergic rhinitis are still antihistamines and nasal corticosteroids, whether it is tree, grass or weed pollen. However, it is important to know which pollen causes the patient's symptoms as nasal corticosteroids should be prescribed at least two weeks before the start of the season. Nasal corticosteroids have been found to be far more effective in controlling allergic rhinitis symptoms when initiated before the season starts, so helping to prevent the development of inflammation. Antihistamines, however, can be used as and when the patients develop their symptoms.

Treatment or management of allergic rhinitis
As we have previously discussed, the majority of patients with seasonal allergic rhinitis can be adequately treated with either antihistamines or a combination of antihistamines and nasal corticosteroids.

Antihistamines
These can be used as symptoms develop, either daily or as required. It is important to ask patients which antihistamine they take as first-generation antihistamines, eg, chlorphenamine, clemastine and hydroxyzine, are effective treatments but do have sedating side-effects causing somnolence, diminished alertness and slow reaction times. Patients should be advised not to drive or operate machinery while receiving these treatments. Second-generation antihistamines, eg, cetirizine, fexofenadine and loratadine, are taken once a day, provide good symptom control and fewer sedating side-effects.
 
Nasal corticosteroids
Nasal corticosteroids reduce nasal inflammation and hypersensitivity. Some nasal steroids have a slower onset of action and can take up to two weeks for maximum benefit to be reached. Therefore they should be commenced two weeks before the beginning of the pollen season. Nasal steroids, such as beclometasone, budesonide, fluticasone, mometasone are effective at reducing symptoms of nasal congestion and anosmia as well as nasal itch, sneezing and rhinorrhoea.
As within the asthma clinic, it is of paramount importance that patients should be educated regarding the regular use of the nasal steroid treatment and also instructed on the correct technique required to ensure maximum benefit from the nasal spray (see Box 1). Incorrect technique and poor concordance can be the main causes of treatment failure and increased patient morbidity. 

[[nip36_45_box1]]

There are a small number of patients who, despite commencing treatment early, demonstrating a good technique and using the treatment as prescribed, remain symptomatic. For these patients, a number of treatments are available.

Leukotriene receptor agonist
The leukotriene receptor agonist, eg, montelukast, was initially launched for the treatment of asthma some years ago. However, more recent work has shown it provides effective relief from allergic rhinitis symptoms as well.(5) This is a useful treatment to consider, particularly as it has a licence in paediatrics. 

Sublingual immunotherapy
Over recent years there has been a development in the treatment of allergic rhinitis in the form of sublingual immunotherapy. The aim of this treatment is to desensitise (or re-educate) the immune system, so when exposed to the provoking allergen, the immune system does not respond aggressively. 75,000SQ-T oral lyophilisate (Grazax; ALK-Abelló) is a new sublingual immunotherapy tablet for the treatment of grass pollen-induced seasonal rhinitis and conjunctivitis in adults. Sublingual immunotherapy should be initiated in patients by physicians who have experience in the treatment of allergic disease, with the first tablet being taken under medical supervision. The once-daily treatment should be initiated 16 weeks before the beginning of the grass pollen season and continued throughout.
In two randomised, double-blind, placebo-controlled trials, Grazax has been shown to reduce symptoms and medication usage in comparison with placebo.(6,7) Mild-to-moderate local side-effects have been described in up to 70% of patients including oral pruritis, headaches, throat irritation, sneezing and conjunctivitis. These local reactions are reported to last from minutes to hours and resolve spontaneously within one to seven days. 
Within the current climate of the NHS, the cost of any treatment is always a major consideration. The cost of Grazax is £67.50 for 30 tablets. The current prescribing guidelines aim to treat patients with symptoms that are moderate to severe and not adequately controlled by a combination of antihistamines and nasal corticosteroids, and those patients who have positive grass pollen skin prick tests or specific IgE.

Summary
The symptoms of seasonal allergic rhinitis cause misery for many of our patients. With a good history and knowledge of your pollen seasons a clinical diagnosis can be made quickly. The importance of education with regard to technique, concordance and treatment can also dramatically change a patient's quality of life. Next time you get a common cold - remember your patients with seasonal allergic rhinitis and perhaps be thankful that you do not have perennial rhinitis!

References

  1. Walker S. Reducing hayfever havoc: keeping symptoms at bay. Br J Primary Care Nurs 2007;1:84-6.
  2. Bauchau V, Durham SR. Prevalence and rate of diagnosis of allergic rhinitis in Europe. Eur Respir J 2004;24:758-64.
  3. Bousquet J, Van Cauwenberge P, Khaltaev N; ARIA Workshop Group; World Health Organization. Allergic rhinitis and its impact on asthma. J Allergy Clin Immunol 2001;108 Suppl 5:147-334.
  4. Coombs RRA, Gell PGH. Clinical aspects of immunology. Oxford: Blackwell Scientific Productions; 1963.
  5. Philip G, Nayak AS, Berger WE. The effect of montelucast on rhinitis symptoms in patients with asthma and seasonal allergic rhinitis. Curr Respir Med Opin 2004;20:1549-58.
  6. Dahl R, Kapp A, Colombo G, et al. Efficacy and safety of sublingual immunotherapy with grass allergen tablets for seasonal allergic rhinoconjunctivitis. J Allergy Clin Immunol 2006;118:434-40.
  7. Durham SR, Yang WH, Pedersen MR, et al. Sublingual immunotherapy with once-daily grass allergen tablets: a randomised controlled trial in seasonal allergic rhinoconjunctivitis. J Allergy Clin Immunol 2006;117:802-9.