By Dr. Harold Kim, Kitchener, Ontario
Rhinitis, nasal inflammation, is a common disorder that occurs in up to 40% of the population. Allergic rhinitis is a specific type of rhinitis that results from IgE-mediated inflammation of the nasal lining. Approximately 10% to 15% of the population suffers from this condition.
Traditionally, allergic rhinitis has been divided into seasonal and perennial variations – but many patients suffer from both. Recently, comprehensive guidelines for the diagnosis and treatment of allergic rhinitis have been published and widely accepted by the medical community. In this article we will discuss allergic rhinitis with a particular focus on the treatment.
Typically, the patient will present with nasal congestion, runniness, sneezing and/or nasal itchiness. Allergic rhinitis sufferers often report a positive family history of allergy. Patients typically volunteer that their symptoms are worse during particular times of the year, or following exposure to specific allergens. The seasonal variation of symptoms will depend on the most common allergens in a particular geographic area, and the specific allergens to which the patient has become sensitive. Within Canada, there is great variation in allergens. Generally, trees pollinate in the spring, grasses in the early summer and ragweed in the late summer and fall. Mold allergens can be present outdoors whenever there is incomplete snow cover. Indoor allergens, such as dust mites and pets, are present throughout the year.
Patients are classified as having moderate/severe symptoms if their rhinitis impacts sleep, if it affects activities of daily living such as school or work, or if the symptoms are generally bothersome. It is important to classify the severity of symptoms in allergic rhinitis, as symptom severity will guide the treatment for individual patients.
Allergy testing is the most effective method available to confirm that underlying allergies causes a patient’s rhinitis. With skin testing, specific allergens can be identified and subsequently avoided. As well, test results will guide allergists in the prescribing of allergen immunotherapy, should it be required later.
Often, we see patients who display symptoms of rhinitis, including nasal congestion, sneezing, sinus pressure or nasal runniness, but who have negative allergy test results. Typically, we classify these patients as having non-allergic rhinitis. A complete discussion on this topic is beyond the scope of this article.
It should be noted that many ‘alternative care’ practitioners perform unusual and scientifically invalid forms of allergy testing. We recommend that patients be discouraged from having these tests performed. Such practitioners often suggest that foods or other unusual allergens are a cause of rhinitis, but it is well established that food allergy is a rare cause of allergic rhinitis. Any results from these types of tests should not be accepted, and a proper allergy assessment should be attained.
Generally, the first line of treatment in allergic rhinitis is the avoidance of relevant allergens, although this intervention may not be effective for all patients. This is especially true for those who, all too commonly, are not compliant with recommended avoidance measures.
Oral antihistamines are the first line medication treatment for allergic rhinitis. More recently, all treatment guidelines have recommended against the use of the older, sedating antihistamines. Their impact on the worsening of sedation and performance of daily tasks has been shown to be significant and potentially dangerous. The newer second-generation antihistamines, lacking sedative properties, are the recommended choice for patients requiring antihistamines. Some of the newer antihistamines have a significant impact on congestion – an effect that was lacking in older medications. The non-sedating antihistamines, with once-per-day dosing, include Aerius (desloratadine), Allegra (fexofenadine) and Claritin (loratadine). If these antihistamines are not effective, then another option is Reactine (cetirizine).
The nasal corticosteroids have been recommended as the second-line treatment for patients with mild allergic rhinitis. They are, however, first-line options for addressing moderate/severe symptoms. These medications, often felt to be the most potent choices available to practitioners, act by affecting the inflammation brought about by allergy. When these medications are used regularly and correctly, the inflammation of allergy can be repaired. The nasal corticosteroids available in Canada include Avamys (fluticasone furoate), Beconase (beclomethasone), Flonase (fluticasone proprionate), Nasacort (triamcinolone acetonide), Nasonex (mometasone furoate), Omnaris (ciclesonide), Rhinalar (flunisolide) and Rhinocort (budesonide).
The nasal corticosteroids are superior to the oral antihistamines in the treatment of allergic rhinitis. Even with regards to allergy of the eye (conjunctivitis), the nasal corticosteroids were found to be as effective as antihistamines. The advantage of nasal corticosteroids over antihistamines is particularly important in perennial rhinitis, where most patients have moderate/severe nasal congestion. In these patients, the nasal corticosteroids should be the main treatment.
The nasal corticosteroids have few adverse effects, but they can cause nasal irritation and nose bleeds. Nosebleed rates for the nasal corticosteroids available in Canada are estimated to be between 10% and 20%. There has been one well-designed study showing that intranasal beclomethasone, but not other corticosteroids, may slow growth in children compared to placebo.
Finally, the sensory attributes of a nasal corticosteroid may have an impact on compliance. Generally, a product that has less smell and irritant sensation will be better tolerated, leading to improved patient outcomes.
Leukotriene Receptor Antagonists
The leukotriene receptor antagonists (LTRAs) are also effective in the treatment of allergic rhinitis. In Canada, Singulair (montelukast) is the only LTRA that is indicated for seasonal allergic rhinitis in adults. This product is generally considered to be safe and well tolerated. At this time, we generally consider LTRA use only when antihistamines and/or nasal corticosteroids are not effective, or are not well tolerated.
We should note that the majority of patients with allergic rhinitis respond to medical therapy. Typically, a patient that presents to a physician’s office will have moderate or severe symptoms. Therefore, these patients usually require a nasal corticosteroid spray. If they do not respond to the nasal steroid spray, then the other therapies listed above, including antihistamines and LTRAs, can be added to the nasal corticosteroid. If the combination of medical therapy is not effective or is not tolerated, then allergen immunotherapy should be considered. We have outlined a proposed therapeutic approach to the treatment of allergic rhinitis in Figure 1.
Allergen immunotherapy has been available for the treatment of allergic rhinitis, conjunctivitis and asthma for almost a century. Essentially, allergen immunotherapy involves the injections of the patient’s relevant allergens in increasing doses, leading to a gradual change in the patient’s immune response to them. Generally, immunotherapy pushes the immune response away from allergy.
There are several well-designed studies that suggest this treatment is effective in both seasonal and perennial allergic rhinitis. Typically, the immunotherapy is given in a perennial, year-round fashion. These injections are given for three to five years, after which there is a prolonged protective effect for many patients. There are some preparations of pre-seasonal immunotherapy available. Also, there may be some sublingual or swallowed preparations of immunotherapy coming to the Canadian market over the next few years.
Only physicians who are adequately trained in the treatment of allergy should prescribe immunotherapy. There are important risks with the injection of allergen immunotherapy, including anaphylactic reactions. Therefore, injections should be given in a medical clinic where a physician is available to treat possible life-threatening anaphylaxis. As with allergy testing, it should be noted that many alternative care practitioners in Canada practice unusual and ineffective forms of ‘immunotherapy’. Patients should be discouraged from receiving these types of treatment.
Allergic rhinitis is a common disorder that often starts in childhood and can persist through the adult years. The diagnosis and treatment of this condition is relatively straightforward – if there is a high degree of suspicion, most patients will be diagnosed appropriately. Once the severity of their condition is assessed, treatment can be prescribed. The treatments available to us are effective and, generally, safe. The nasal corticosteroids are the recommended treatments for moderate/severe allergic rhinitis.
from Allergy & Asthma News, Issue 2 2008