Allergic Rhinitis These materials are for your general information and are not a substitute for medical advice. You should contact your physician or other healthcare provider w ith any questions about your health, treatment, or care. Do not contact UpToDate or the physician authors of these materials. OVERVIEW — Rhinitis refers to inflammation of the nasal passages. This inflammation can cause a variety of annoying symptoms, including sneezing, itching, nasal congestion, and runny nose. Almost everyone experiences rhinitis at some time in his or her life. Brief episodes of rhinitis are usually caused by respiratory tract infections with viruses (the common cold). Chronic rhinitis is usually caused by allergies, but it can also occur from overuse of certain drugs, some medical conditions, and unidentifiable factors. For many people, rhinitis is a lifelong condition that waxes and wanes over time. Fortunately, the symptoms of rhinitis can usually be well controlled with some combination of environmental measures, drug therapy, and immunotherapy. ALLERGIC RHINITIS — Allergic rhinitis, commonly know n as hay fever or grass fever, is common, affecting about 20 percent of people of all ages. The risk of developing allergic rhinitis is much higher in people w ith asthma or eczema, and in people who have a family history of asthma or rhinitis. Allergic rhinitis can begin at any age, although most people first develop symptoms in childhood or young adulthood. The symptoms are often at their worst in children and in people in their 30s and 40s. However, the severity of symptoms tends to vary throughout life, and many people experience periods of remission. Cause of allergic rhinitis — Allergic rhinitis is caused by a nasal reaction to small airborne particles called allergens (substances that provoke an allergic reaction) [ 1 ]. In some people, these particles also cause reactions in the airways (asthma), lungs (allergic pneumonitis), a nd eyes (allergic conjunctivitis). The allergic reaction is characterized by activation of two types of inflammatory cells, called mast cells and basophils. These cells produce inflammatory substances, including histamine, that cause blood vessel dilation, itching, sneezing, and runny nose. Over several hours, these substances also activate other inflammatory cells that may cause a second wave of symptoms. Seasonal versus perennial allergic rhinitis — Allergic rhinitis can be seasonal (occurring during spec ific seasons) or perennial (occurring year round). The allergens that most commonly cause seasonal allergic rhinitis are the pollen of trees, grass, and weeds, as well as fungi and molds. The allergens that most commonly cause perennial allergic rhinitis are house dust, dust mites, cockroaches, animal dander, and fungi or molds. Of these two types of allergic rhinitis, perennial allergic rhinitis tends to be more difficult to treat. Symptoms of allergic rhinitis — The typical symptoms of allergic rhinitis include an itching nose and sometimes ears; sneezing; a clear, watery nasal discharge; sore throat; and difficulty breathing through the nose. In severe cases, the symptoms may also include a sensation of facial pressure and facial pain. The nasal symptoms of allergic rhinitis are often accompanied by itching and watery eyes, and sometimes by swelling and blueness of the tissue beneath the eyes (called "allergic shiners"). Other symptoms of allergic rhinitis may include a loss of taste and smell, sleep disturbances, daytime fatigue, and difficulty performing work. After exposure to an allergen and an initial reaction, about 30 to 40 percent of people have a recurrence of symptoms 6 to 12 hours later [ 2]. Exposure to nonspecific stimuli, such as strong odors or irritants, may also precipitate or worsen symptoms in people with allergic rhinitis. Diagnosis of allergic rhinitis — The diagnosis of allergic rhinitis is based upon the presence of the signs and symptoms of this condition described above. A nasal examination and medical tests can confirm the diagnosis and identify the offending allergens. Nasal examination — A nasal examination allows direct visual inspection of the lining of the nasal passages and can occasionally differentiate allergic rhinitis from other types of rhinitis. In people with allergic rhinitis, the lining of the nasal passages is often very pale or blue. Identification of allergens and other triggers — It is often possible to identify the allergens and other triggers that provoke allergic rhinitis by recalling the factors that precede symptoms; noting the time at which symptoms begin; and examining a person's home, work, and school environments. Skin tests may be useful for people whose symptoms are not well controlled with medications and in whom the offending allergen is not obvious. Treatment of allergic rhinitis — The treatment of allergic rhinitis entails a combination of measures to reduce a person's exposure to known allergens or other triggers and drug therapy. In most people, these measures effectively control the symptoms of allergic rhinitis. Reducing exposure to triggers — Some simple measures can reduce a person's exposure to the allergens and triggers that provoke allergic rhinitis. These measures do not apply to everyone with allergic rhinitis, but should be applied to anyone who has a known allergen that triggers symptoms. Dust mites — Exposure to dust mites can be reduced by encasing mattresses and pillows in mite-impermeable barriers and washing sheets and blankets weekly in very hot water (at least 130 degrees Fahrenheit). Exposure can be further reduced by keeping indoor humidity at less than 50 percent, vacuuming regularly, removing carpets that lie on concrete, and avoiding sleeping or lying on upholstered furniture. Animal dander — Exposure to animal dander can be reduced by keeping pets out of bedrooms, sealing or placing filters over the air vents to bedrooms, and bathing cats w eekly. In some cases, it may be necessary to remove pets from the home. Because dander can linger in an environment long after a pet has been removed, a person's symptoms may not improve for several months. Cockroaches — Exposure to cockroaches can be reduced by using poison bait or traps and by keeping food and garbage tightly enclosed at all times. Indoor molds — Exposure to indoor molds can be reduced by fixing leaks, eliminating water sources where mold can grow, cleaning moldy surfaces, and reducing indoor humidity to less than 50 percent. Pollens and outdoor molds — Exposure to pollens and outdoor molds can be reduced by keeping car and house windows closed, staying in air-conditioned rooms during the season of peak symptoms, and staying inside on sunny, windy days. The American Academy of Allergy, Asthma, and Immunology has a toll free number (1-800-976-5536) and website ( www.aaaai.org ) for checking pollen and mold spore counts before heading outdoors. Tobacc o smoke — Exposure to tobacco smoke can be reduced if household members stop smoking or smoke only outside of the home. It is also important to reduce smoke exposure in the day care setting and in the workplace. Pollutants and irritants — Exposure to pollutants and irritants can be reduced by avoiding wood-burning stoves and fireplaces; properly venting other stoves and heaters; and avoiding perfumes, cleaning agents, and sprays that trigger symptoms. High-efficiency particulate air (HEPA) cleaners — The effectiveness of high-efficiency particulate air (HEPA) cleaners in reducing a person's exposure to allergens is uncertain. These cleaners are not very effective for reducing exposure to dust mite allergen because little of this allergen is airborne. However, some studies have suggested that HEPA cleaners may be effective for removing cat allergens from the air. Drug therapy — Several different classes of drugs counter the inflammation that causes symptoms of allergic rhinitis. The severity of symptoms and personal preferences usually guide the selection of specific drugs. Nasal steroids — Nasal steroids (steroids taken by a nasal spray) are usually the drugs recommended first for the treatment of allergic rhinitis. These drugs have very few side effects and dramatically relieve symptoms in most people. One study showed that nasal steroids were more effective than oral antihistamines for symptom relief [ 3]. The nasal steroids include beclomethasone (Vancenase, Beconase), budesonide (Rhinocort), flunisolide (Nasarel), fluticasone (Flonase), mometasone (Naso nex), and triamcinolone (Nasocort). These drugs differ with regard to the base liquid (water-based versus alcohol-based), the frequency of doses, the spray device, and cost, but all are similarly effective for treating rhinitis symptoms. People with severe rhinitis may be advised to also use nasal decongestants for a few days to reduce nasal swelling and allow the steroid spray better access to the nasal passages. Some symptom relief may occur on the first day of therapy with nasal steroids, but their maximal effectiveness may not be apparent for days to weeks. For this reason, these drugs are most effective when used regularly, although some people are able to gradually use lower doses w ithout a return of symptoms. Adequate dispersal of the nasal spray to the nasal lining is important for the effectiveness of nasal steroids. This dispersal can be improved by directing the spray away from the nasal septum (the cartilage that divides the two sides of the nose), using an alcohol-based spray, and positioning the head down and forward after using water-based sprays. The side effects of nasal steroids are mild and may include a slight unpleasant smell or taste or drying of the nasal lining. In some people, nasal steroids cause irritation, crusting, and bleeding of the nasal septum, especially during the winter; this side effect can be minimized by applying Vaseline before using the spray, using a saline nasal spray to restore moisture to the nasal lining, or switching to a water-based spray. Studies suggest that nasal steroids are generally safe when used for many years. However, people who use these drugs for prolonged periods of time should have periodic nasal examinations to check for rare side effects, including damage of the nasal septum and nasal infection. Although oral and inhaled steroids have been linked to reduced bone mineral density and hormonal side effects (including poor growth in children), nasal steroids do not appear to have these side effects. However, to be on the safe side, doctors usually recommend using the lowest effective dose of nasal steroids. Antihistamines — Antihistamines relieve the itching, sneezing, and runny nose of allergic rhinitis, but they do not relieve nasal congestion. Combined treat ment with nasal steroids or decongestants may provide greater symptom relief than use of either alone. The oral, over-the-counter antihistamines include brompheniramine (Dimetapp allergy, Nasahist B), chlorpheniramine (Chlor-Trimeton), diphenhydramine (Benadryl), and clemastine (Tavist). These drugs often cause sedation and should not be used before driving. Simultaneous use of a decongestant may reduce the sedating effects, but this is not reliable. The oral, prescription antihistamines include cetirizine (Zyrtec), fexofenadine (Allegra), and loratadine (Claritin). These drugs are much less sedating, and some are available in long-acting formulas. Prescription antihistamines are more expensive than over-the-counter antihistamines and are not more effective for treating rhinitis symptoms. The nasal, prescription antihistamine azelastine (Astelin) also relieves the symptoms of allergic rhinitis. This drug is expensive and may be associated with an unpleasant taste, a brief burning sensation, and sedation in some people. Decongestants — Decongestants (like pseudoephedrine [Sudafed, Actifed, Drixoral]) are often combined with antihistamines in oral, over-the-counter allergy drugs. Several decongestant nasal sprays also are available, including oxymetazoline (Afrin) and phenylephrine (Neo-synephrine). Nasal dec ongestants should not be used for more than two to three days at a time because they may cause a different type of rhinitis, called rhinitis medicamentosa (see below). The oral decongestants elevate blood pressure and are not appropriate for people with hypertension (high blood pressure) or certain cardiovascular conditions. Men w ith an enlarged prostate who have difficulty urinating may notice a worsening of this symptom when they take decongestants. Cromolyn sodium — Cromolyn sodium (Nasalcrom, Intal, Crolom, Gastrocrom) relieves the symptoms of allergic rhinitis by stabilizing mast cells, the cells that can release substances which cause inflammation. This drug is available as an over-the-counter nasal spray that must be used three to four times per day, preferable before symptoms have begun, to effectively prevent the symptoms of allergic rhinitis. Cromolyn sodium has not been associated with any serious side effects. Saline nasal spray — A saline nasal spray is effective for minimizing the nasal dryness and postnasal drip that may be associated with allergic rhinitis and its treatment. Saline nasal sprays can be purchased over-the-counter or can be made at home. T he home- made spray is prepared by mixing 1/4 teaspoon of salt, 1/8 teaspoon of baking soda, and 1 cup of water; the solution can be put into an old nasal spray bottle. The spray should be made fresh each day to avoid contamination with bacteria. Immunotherapy (desensitization therapy) — Immunotherapy refers to injections that are given to desensitize a person to known allergens. This therapy is effective for only certain types of allergens, and it is both expensive and time-consuming. Although immunotherapy can benefit many people with allergic rhinitis, it is usually reserved for people who have a poor response to drug therapy or who are reluctant to take drugs. Immunotherapy has been shown to be effective for the treatment of allergies to cat dander and t he pollen of trees, weeds, and grass. Immunotherapy is usually started by an allergist. The therapy begins with several months of weekly injections of gradually increasing doses, followed by monthly maintenance injections. The maintenance injections can be given by a primary care provider. Immunotherapy is usually a long-term therapy, and the benefits of this therapy may lessen when it is discontinued. However, one study in people with allergies to grass pollen found that the benefits of three to four years of immunotherapy persisted when the injections were stopped [ 4]. Immunotherapy injections carry a small risk of a severe allergic reaction. These reactions occur with a frequency of 6 of every 10,000 injections, most often after maintenance injections. The symptoms usually begin within 30 minutes of the injection and can be fatal, especially in people with severe asthma; this is why patients are asked to remain in the office after routine injections. Because drugs called beta-blockers may interfere w ith the ability to treat these reactions, people who take these drugs are often advised not to have immunotherapy. Other treatments — Other drugs have been studied in people with allergic rhinitis with inconclusive results. Nasal atropine — Nasal atropine is effective for the treatment of severe runny nose. This drug, available as ipratropium bromide (Atrovent), is often not recommended for people with glaucoma and men with an enlarged prostate. Leukotriene receptor antagonists — Release of substances called leukotrienes may contribute to the symptoms of allergic rhinitis. Drugs that inhibit the action of leukotrienes, called leukotriene receptor antagonists, can be very useful in patients with asthma. Reports have been conflicting in patients with allergic rhinitis, and these drugs are not yet recommended for this purpose in most patients. IDIOPATHIC RHINITIS — Idiopathic rhinitis, formerly called vasomotor rhinitis, refers to rhinitis that has no identifiable cause. Researchers believe that this type of rhinitis may result from the abnormal dilation of blood vessels. The symptoms of idiopathic rhinitis include a watery nasal discharge; intermittent nasal congestion; and an exaggerated nasal response to nonspecific irritants, such as air pol lution or temperature change (especially exposure to cold, dry air). Unlike allergic rhinitis, idiopathic rhinitis is not accompanied by nasal itching, itching of the eyes, or sneezing. Idiopathic rhinitis is often difficult to treat. Reducing or eliminating exposure to airborne irritants appears to be the most effective strategy for treating this condition. The oral drug ephedrine and the nasal drug ipratropium bromide (Atrovent) alleviate symptoms in some people w ith idiopathic rhinitis. Over-the-counter nasal decongestants should be avoided because these drugs may lead to another type of rhinitis, called rhinitis medicamentosa (see below). ATROPHIC RHINITIS — Atrophic rhinitis is a type of rhinitis that results from a gradual thinning of the nasal lining and the nasal bones. This condition most commonly occurs in older adult s. The symptoms include nasal congestion, crusting of the nasal passages, and a persistent bad smell. Treatment with topical antibiotics and a saline spray often relieves the symptoms of atrophic rhinitis. RHINITIS MEDICAMENTOSA — Rhinitis medicamentosa is a type of rhinitis that is initiated and perpetuated by the use and overuse of a certain drugs. The condition is most often caused by the overuse of decongestant nasal sprays (not nasal steroids), but it can also be caused by the use of oral contraceptives, antihypertensive drugs, antidepressants, sedatives, and aspirin . Rhinitis medicamentosa is treated by discontinuing the drug that is causing the condition, after first consulting a doctor. Steroid nasal sprays can speed the recovery from this condition, but recovery may take as long as one year [ 5 ]. MEDICAL CONDITIONS ASSOCIATED WITH RHINITIS — Rhinitis can be a symptom of several underlying medical conditions, including hypothyroidism, certain tumors, conditions that cause vascular inf lammation, and cocaine use. Treatment of these underlying conditions may relieve rhinitis. Pregnancy can also cause rhinitis in some women. NASAL POLYPS — Nasal polyps are painless overgrowths of the lining of the sinuses. These polyps may result from the persistent inflammation of allergic rhinitis, among other causes. Nasal polyps can narrow the nasal passages and cause a watery discharge. Nasal polyps can be difficult to treat. Nasal steroids can often halt the growth of nasal polyps and may cause them to shrink. A brief treatment with oral steroids followed by maintenance treatment with nasal steroids can also control the growth of nasal polyps. Surgery to remove nasal polyps (called polypectomy) may be necessary when the polyps severely narrow the nasal passages or cause recurrent sinusitis that requires antibiotic treatment. Polyps often grow back after surgery, although this can be retarded by use of corticosteroid nasal sprays.