Update on Allergic Rhinitis (Hayfever)
To Your Health -- CHRC Newsletter
Last Reviewed: May 2005
Peter Maguire, M.D., FAAAAI and Robert C. Bocian M.D., Ph.D., FAAAAI
Allergic rhinitis (AR) is the second most common chronic condition in the United States, outranked only by hypertension. AR affects at least 20 percent of the U.S. population, and is an especially common condition in the Bay Area because of mild weather conditions, and an abundance of pollinating native and non-native plants. Approximately two thirds of people with allergic rhinitis are "bothered a great deal" by their symptoms. Patients with allergic rhinitis are, on the average, symptomatic for nine months each year. Health problems associated with AR have significant economic consequences. Current estimates suggest that the total cost of allergic rhinoconjunctivitis for the U.S. is around $6 billion.
While allergic rhinitis may develop at any age, approximately 70 percent of patients develop the disorder before the age of 30. The incidence is highest between the ages of 15 and 25 years. There is evidence of a genetic predisposition to allergic disorders. AR is found in roughly a third of children who have one parent or sibling with a history of allergic disease and a little less than two thirds in children of two such parents.
Symptoms and Diagnosis
Common symptoms of AR include nasal drainage (anterior as well as posterior), nasal congestion, itching of the nose and palate, sniffling and nasal rubbing ("allergic salute") and sinus congestion which may lead to significant headache. AR symptoms may lead to other medical problems involving the ears, eyes and sinuses since all three areas have direct anatomical connection to the nasal passages. When allergy symptoms are bad, quality of life can be affected. People with AR may also experience poor concentration, fatigue, irritability and sometimes in extreme cases depression. Moreover, AR has a significant association with asthma, sinusitis, conjunctivitis, otitis media (middle ear-ear inflammation), and decreased sense of smell and taste.
AR can be a subtle diagnosis, since it may mimic or coexist with a number of other nonallergic disorders. Among these are nasal/sinus infections, drug-induced rhinitis, occupational rhinitis, hormonal rhinitis, vasomotor rhinitis, systemic inflammatory/immunologic disorders, and structural upper-respiratory abnormalities. In some contrast to nonallergic disorders, AR usually includes the annoying feeling of itchiness. Evaluation for AR should include an assessment of symptoms, extensive patient and family history, an appraisal of the patient's indoor and outdoor environment, physical examination and, when appropriate, diagnostic testing (via skin or blood).
AR may be classified as episodic, seasonal, or perennial (with or without seasonal exacerbations). Classification often is more problematic in the Bay Area where (1) many locations have a gamut of pollen releasing plants including grasses, trees and weeds; (2) climatic features favor the perennial thriving of dust mites and molds, and (3) ownership of indoor furry pets is high.
Management
The three traditional components of AR management are allergen avoidance, medication therapy and allergen immunotherapy. Allergy testing can help select which components of AR management will be most effective. Allergen avoidance, often referred to as environmental control, when of sufficient duration and magnitude, reduces allergen-driven inflammation in the nasal membranes and thereby reduces allergic symptoms.
Dust mites
Removal of sites in which dust mites accumulate (carpets, feather pillows, upholstered furniture, nonwashable clothing, blankets, comforters, stuffed animals, drapes, etc.) is effective but often easier said than done. Although costly, removal of wall-to-wall carpeting may be particularly helpful for the dust allergic person. Mattresses and pillows should be encased with vapor-permeable, mite allergen-impermeable encasings. Vacuuming with a machine equipped with a HEPA (high-efficiency particulate arresting) filtration system or a double-layered ("microfiltration") bag further reduces the scattering of dust.
Fungal allergens
Since fungi and mites both thrive under relatively humid and warm conditions, several measures taken to limit accumulation of dust-mite allergen will also help control fungal allergens, including measures to maintain indoor relative humidity below 50 percent and temperature below 70 F. Even natural or artificial light can inhibit mold growth.
Animal dander
Although removal of the relevant pet is objectively the most effective method of environmental control, this hardship is often a last resort method. Restriction of a pet to the outdoors when feasible, limitation of the indoor range of the pet, regular washing when feasible, removal of reservoirs of dander (carpeting, fabric furniture), and HEPA filtration are helpful in decreasing airborne dander allergen.
Seasonal pollen allergens
With the extensive variety and often high density of airborne pollens of grasses, weeds and trees of northern California, this is a difficult category of allergen avoidance. Windy, dry and sunny days can be especially problematic, allowing greater dispersion of airborne pollen. Allergy testing can help define which categories of pollen are important triggers for the individual.
Medication therapy
There are a variety of over-the counter (OTC) and prescription medications available on the market. Many of the OTC medications tihistamines with or without the decongestant pseudoephedrine. Many people self-medicate with these products with success, but those with more than mild allergy problems may have incomplete relief. Additionally, potential side effects of medications need to be considered. Prescription nasal sprays and newer forms of allergy medication may provide more extended relief of allergy symptoms. In general, anti-allergy medications are most effective if taken before allergic symptoms develop.
Antihistamines (oral, nasal spray)
Antihistamines, which block the histamine receptor, help prevent or relieve symptoms of sneezing, itching of the nose, eyes, middle ear, palate and skin, and nasal drainage. Used alone, they generally do not relieve nasal congestion readily, and are not classified as anti-inflammatory (allergic inflammation). Classic, nonprescription antihistamines, e.g. diphenhydramine (Benadryl®) pose the risks of sedation, dryness of mucous membranes of the eye, nose and mouth, dizziness, slowed reaction time, and other untoward side effects. OTC loratadine (Allerclear®, Alavert®, Walitin®, Claritin® etc.) is a longer lasting non-sedating antihistamine, but does not always alleviate symptoms effectively. Desloratadine (Clarinex®) is a new prescription non-drowsy antihistamine, however, its effectiveness and side effect profile (low) is similar to that of OTC loratadine. Classified as a prescription non-drowsy antihistamine, fexofenadine (Allegra®) is available in different strengths and can offer superior relief compared to loratadine. Cetirizine (Zyrtec®) can be especially effective at relieving allergic symptoms that include itching. Most people do not experience noticeable sedation with cetirizine, but some may be adversely affected. Pilots are advised not to fly if taking cetirizine. The nasal antihistamine spray, azelastine (Astelin®), is useful against the purely nasal symptoms of AR, but can have an unpleasant smell or after-taste, especially if administered without proper nasal inhalation technique.
Decongestants (oral, nasal spray)
Pseudoephedrine (common brand name Sudafed®) is available in different strengths, and is intended to relieve nasal congestion temporarily. It works by constricting blood vessels that permeate the nasal membranes, causing swollen nasal tissue to shrink, and thus allow greater airflow through the nasal passages. Many combination antihistamine + pseudoephedrine brands are available OTC, as well as by prescription, such as Allegra-D® and Zyrtec-D®. However, oral decongestants may cause central nervous system side effects including insomnia and irritability, and may aggravate co-existing conditions including glaucoma, urinary retention, hypertension and palpitations. Nasal spray decongestants, such as oxymetazoline (Afrin®), work quickly but cause significant "rebound" nasal congestion. Although OTC, decongestant sprays should be used with caution, typically for urgent needs only, and should be discontinued as soon as possible.
Corticosteroid nasal sprays
Prescription corticosteroid nasal sprays are significantly more effective than antihistamines in taming the symptoms of AR since they reduce allergic inflammatory responses in the nasal membranes. Although peak effect is achieved after a week or more of therapy, recent studies show that significant control of AR symptoms may be attained within the first day of use. Optimal benefit is seen with consistent usage, typically 2 sprays each nostril per day. Examples of intranasal steroids include beclomethasone (Beconase AQ®), budesonide (Rhinocort AQ®), fluticasone (Flonase®), mometasone (Nasonex®) and triamcinolone (Nasacort AQ®) among others. For treatment of seasonal AR, this type of medication is most effective if started 1 to 3+ weeks prior to the onset of the relevant pollination. Side effects can include nasal dryness, irritation, and nasal bleeding in rare cases. Cromolyn sodium nasal spray OTC cromolyn sodium (Nasalcrom®) nasal spray is effective for many individuals with mild symptoms of AR, but may require days to weeks of consistent use to achieve efficacy. This nasal spray usually requires frequent administration (usually four times per day) to be effective.
Leukotriene blockers
Montelukast (Singulair®) and zafirlukast (Accolate®) are two additional medications that can help alleviate allergic symptoms in combination with other agents, or even if taken alone. They both block the action of an allergic inflammatory chemical called the leukotriene. Leukotrienes, like histamines, are produced and released in humans with hyper-reactive allergic immune systems. These two medications can help reduce symptoms of nasal congestion, nasal drainage and sneezing. They also help prevent and control symptoms of asthma.
Allergen immunotherapy
Allergen immunotherapy, often called "allergy shots," entails the injection of increasing doses of an allergen to prevent symptoms that are triggered by natural exposure to the allergen. Immunotherapy induces protective immunity against allergens in ways similar to other vaccines. Formulations for injection therapy are customized according to the patient's allergy-test results. Because immunotherapy is administered for years to the individual, and requires repeated injections to safely build up both tolerance and protection against allergens, this form of therapy is generally indicated for those with severe symptoms. Long term experience demonstrates that this form of therapy is quite safe. However, allergen immunotherapy must be given by trained personnel who are qualified to monitor for possible, but rare, immediate allergic side effects.
Anti-IgE therapy
Omalizumab (Xolair®) is a designed antibody (monoclonal antibody) that binds with and inactivates the allergic antibody IgE. Although not yet FDA approved for individuals with only AR, patients with moderate or severe asthma and AR are candidates for this new form of anti-allergy therapy currently. Anti-IgE has been demonstrated to reduce AR symptoms in asthmatics. Ongoing investigation is exploring the effectiveness of this type of injection for treatment of AR without asthma, as well as other allergic disorders such as food allergy and eczema (atopic dermatitis). This form of therapy requires repeated injections to maintain the inactivation of IgE allergic antibody.
Conclusion
The best way to treat AR employs preventative strategies. Education about environmental allergens, and understanding how to avoid them is key in developing successful environmental control. When indicated, anti-allergy medications are most effective if taken before allergen exposure, and before symptoms of allergy become more severe. Nasal corticosteroids can be especially effective, but need a longer period of administration to reach maximal effectiveness, compared with other types of anti-allergy medication. If symptoms of AR are moderate or severe, allergy testing and consultation with a board certified allergist may be necessary to develop the optimal treatment plan.