U.S. Pharmacist

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Minimizing the Discomfort of Allergic Rhinitis

W. Steven Pray, PhD, DPh
Bernhardt Professor of Nonprescription Drugs and Devices
College of Pharmacy
Southwestern Oklahoma State University
Weatherford, Oklahoma


7/18/2008

US Pharm. 2008;33(7):12-15.

Allergic rhinitis (AR) is a common medical condition that afflicts millions of Americans. Providing education about causes, avoidance measures, and treatment options can help reduce the burden to patients. The pharmacist is in an ideal position to help prevent and alleviate the suffering of those asking for assistance with AR.

Prevalence
Allergic rhinitis is thought to affect as many as 25% to 30% of adults and 40% of children, with an estimated prevalence of 20 to 40 million U.S. residents.1,2 AR was once less common, but the incidence has steadily been increasing, perhaps due to such factors as increasing pollution, more time spent indoors, and the installation of indoor carpeting.3,4 The prevalence is now so high that AR has been identified as the most common medical condition of childhood.5

Etiology
The common thread in AR is inhalation of an aeroallergen, which initiates a cascade of events involving immunoglobulin E (IgE), leading to degranulation of mast cells or basophils and the subsequent release of preformed inflammatory mediators.2,6,7

Triggers
A host of aeroallergens trigger AR. The causes are so diverse that clinicians classify the condition based on the temporal nature of the attacks.8 Some patients suffer from AR at virtually any time of the year, without respect to any discernible time pattern. These patients are said to experience perennial AR.9 The causes include such provoking factors as dog/cat dander, dust mite residue, cleaning sprays, cosmetics, cigarette smoke, cockroaches, and molds.7

Other patients have seasonal AR, experiencing symptoms that worsen markedly at certain predictable times of the year. These usually coincide with the presence of a specific type of pollen, such as plant, weed, or tree.

The classification of AR cases as seasonal or perennial is not mutually exclusive. A patient may have both. The patient may be allergic to cat dander, but also to pollens. Thus, he or she may experience symptoms year-round, but with an increased incidence of episodes during the peak pollen seasons. Mold allergy can cause both types of AR. The patient may complain of symptoms after taking a shower or when in the bathroom due to household mold. The number of episodes may increase after seasonal rains, when molds in the outside environment sporulate in response to the increased moisture.

Manifestations
Patients with AR typically experience a constellation of symptoms.5,8 The most bothersome and prevalent involve the nose and its function. The nasal passages become congested, impairing the ability to breathe and the sense of smell, as well as requiring the patient to attempt to blow the nose to clear it. The nose also produces clear, watery discharge, necessitating frequent wiping. The nose begins to itch, especially in the posterior portion, causing the patient to attempt to relieve it by rubbing the nose with the heel of the hand. The patient also experiences paroxysms of sneezing, as many as 10 to 20 in a row. While the sneezes may resemble the loud lung-clearing sneezes that characterize the common cold, they are more commonly shallow and barely audible.

Ophthalmic symptoms such as conjunctivitis, pruritus, and redness can be caused by AR. It can increase the risk of sinusitis, otitis media, and asthma, and cause sleep disturbances, malaise, weakness, and fatigue.1,8,10 AR may also have more far-reaching consequences, including reduced quality of life, psychological effects, and impaired ability to process cognitive input, leading to learning disability.11

Patients with AR have reported the following symptoms: congestion (78%), rhinorrhea (62%), postnasal drip (61%), ophthalmic redness and pruritus (53%), tearing (51%), sneezing episodes (51%), headache (51%), pruritus (46%), facial pain (43%), and ear pain (30%).11

Avoidance Interventions
The obvious advice for patients with AR is complete avoidance of the offending allergen.7 Allergen avoidance techniques include proper household cleaning to reduce dust mites and molds, avoiding contact with pets, using hypoallergenic bedding and air purifiers, and minimizing outdoor activities. However, avoidance is difficult at best and may be virtually impossible.

Nonprescription Options
Due to the impracticality of allergen avoidance, many patients require medical therapy. The first-line agents are less-sedating second-generation antihistamines, two of which are now available on a nonprescription basis: cetirizine (Zyrtec) and loratadine (Claritin, Alavert).10,12,13 In addition to the standard warnings against use if pregnant or breastfeeding, both agents are also contraindicated in patients with liver or kidney disease, and cetirizine must not be taken by patients with an allergy to hydroxyzine.

The patient's age must be discovered prior to making a recommendation. Some products (e.g., Children's Claritin Syrup, Children's Zyrtec Liquid) are FDA approved for use in patients as young as 2 years. Furthermore, cetir­ izine is not considered safe for self-use in patients aged 65 and older.

Loratadine is generally considered nonsedating. Cetirizine is usually given this designation, but a careful examination of its nonprescription product label reveals that the potential for drowsiness is greater than for loratadine.14 Nonprescription cetirizine products carry specific labels to warn the patient that drowsiness may occur. Thus, the patient with concerns about drowsiness might benefit from a recommendation for loratadine rather than cetirizine.

First-generation antihistamines remain available as nonprescription products, but the increased incidence of sedation in patients has caused them to be largely eclipsed by the safer second-generation antihistamines. First-generation antihistamines include diphenhydramine (Benadryl), chlorphenir­ amine (Chlor-Trimeton), and clemastine (Tavist). They are contraindicated in patients with difficulty in urination due to enlargement of the prostate, glaucoma, or breathing problems such as emphysema or chronic bronchitis.15

The age of the patient must also be noted carefully before the pharmacist makes a recommendation for a first-generation antihistamine. None are FDA approved for use in patients under the age of 6 years. Oral decongestants may be necessary to relieve nasal congestion that is not treated by antihistamines.7

The pharmacist can also suggest a trial of intranasal cromolyn sodium (Nasalcrom) for patients aged 6 years and older.7,15 Used as directed one week before exposure to a known or suspected allergen, it can prevent symptoms from developing. It can also be used each day that the patient is in contact with the provoking agent. It should not be recommended for patients with fever, discolored nasal discharge, sinus pain or infection, wheezing, asthma, or cold symptoms.

Prescription Options
The pharmacist frequently encounters patients who have faithfully and carefully followed all directions on nonprescription products but still do not obtain adequate relief. These patients should be referred to a board-certified allergist or immunologist for a full evalua­ tion.7 Patients will usually be given a sophisticated series of tests designed to identify the specific allergens responsible for their symptoms. Once this has been done, the clinic will institute a specific immunotherapy regimen to modify the biological response to the identified allergens.10

Patients usually take weekly injections of allergens in gradually increasing doses. The mechanism by which this method reduces allergic rhinitis is not fully elucidated but is thought to involve gradual stimulation of the immune system, with the resultant effect of preventing mast cell degranulation. However, patients must be observed for a short time following each injection to ensure that they do not experience anaphylaxis. Improvement may not occur until six to 12 months of therapy have elapsed, but allergists report success rates as high as 80% to 90% for some allergens.13

There are numerous prescription interventions for AR. Prescription second-generation antihistamines include fexofenadine (Allegra), levocetirizine (Xyzal), and desloratadine (Clarinex). However, even prescription antihistamines have limited ability to combat nasal congestion, and physicians may prescribe nasal corticosteroids to help relieve persistent congestion.10

Leukotriene receptor antagonists such as montelukast (Singulair) or zafirlukast (Accolate) may provide relief for some patients. Nasal cortico­ steroids (e.g., beclomethasone [Beconase AQ], budesonide [Rhinocort Aqua], fluticasone [Veramyst], triamcinolone [Nasacort AQ], mometasone [Nasonex]), intranasal antihistamines (e.g., azelastine [Astelin]), and intranasal anticholinergics (e.g., ipratropium [Atrovent]) can also be important adjuncts to improve patient well-being.13



Avoid Unproven Allergy Techniques
Chiropractors, naturopathic "physicians," nutritional consultants, and other practitioners may mislead patients into believing they are allergic to specific antigens through use of an unproven diagnostic technique known as applied kinesiology or muscle response testing.15 In the most common form, patients are asked to stand erect, with one arm stretched out at a 90-degree angle. The healer places a hand on the wrist of that arm and tells the patient to resist a downward pressure. The healer then pushes down on the arm. If the patient resists, the muscle is strong. Then the test for allergies begins. The patient may be asked to chew or suck on a suspected allergen, place it under the hand, or hold it in the opposite hand. The healer then presses down on the arm again. If the patient cannot resist the pressure, he is said to be allergic to the allergen. In other versions of this unproven technique, the patient makes a circle with the fingers of one hand that the healer tries to pull apart, or holds the hand against the chest while the healer tries to pull it away. Of course, the healer will often then attempt to sell the patient unproven remedies for the allergy, such as dietary supplements or homeopathic nostrums of un­ known safety and efficacy.

There is no support in legitimate medicine for this chiropractor-developed technique, nor is there any support for the concept that a patient contacting an allergen suddenly experiences weakness. The reverse is true. Patients who are allergic to poison ivy and walk in the woods frequently contact the plant without the slightest indication that they have done so until the dermatitis manifests. Patients whose allergies have been "identified" using this technique must be referred to an allergist for legitimate testing as previously described.



REFERENCES
1. Santos CB, Pratt EL, Hanks C, et al. Allergic rhinitis and its effect on sleep, fatigue, and daytime somnolence. Ann Allergy Asthma Immunol. 2006;97:579-586.
2. Lehman JM, Blaiss MS. Selecting the optimal oral antihistamine for patients with allergic rhinitis. Drugs. 2006;66:2309-2319.
3. Sheikh A, Hurwitz B, Shehata Y. House dust mite avoidance measures for perennial allergic rhinitis. Cochrane Database Syst Rev. 2007;(1):CD001563.
4. Mösges R, Klimek L. Today's allergic rhinitis patients are different: new factors that may play a role. Allergy. 2007;62:969-975.
5. Dowdee A, Ossege J. Assessment of childhood allergy for the primary care practitioner. J Am Acad Nurse Pract. 2007;19:53-62.
6. Rosenwasser L. New insights into the pathophysiology of allergic rhinitis. Allergy Asthma Proc. 2007;28:10-15.
7. Seth D, Secord E, Kamat D. Allergic rhinitis. Clin Pediatr. 2007;46:401-407.
8. Bahls C. In the clinic. Allergic rhinitis. Ann Intern Med. 2007;146:ITC4-1–ITC4-16.
9. Saleh HA, Durham SR. Perennial rhinitis. BMJ. 2007;335:502-507.
10. Baena-Cagnani CE, Passalacqua G, Gómez M, et al. New perspectives in the treatment of allergic rhinitis and asthma in children. Curr Opin Allergy Clin Immunol. 2007;7:201-206.
11. Nathan RA. The burden of allergic rhinitis. Allergy Asthma Proc. 2007;28:3-9.
12. Lanier B. Allergic rhinitis: selective comparisons of the pharmaceutical options for management. Allergy Asthma Proc. 2007;28:16-19.
13. Sheikh J. Rhinitis, allergic. eMedicine. May 9, 2008. www.emedicine.com/MED/topic104.htm. Accessed May 30, 2008.
14. Zyrtec (cetirizine) package insert. Fort Washington, PA: McNeil-PPC, Inc; 2007.
15. Pray WS. Nonprescription Product Therapeutics. 2nd ed. Baltimore, MD: Lippincott Williams & Wilkins; 2006.
16. bioAllers 3 new allergy formulas. Tsang Nutrition. http://tsangenterprise.com/allergy.htm. Accessed May 30, 2008.

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