Allergic rhinitis is an allergic response to outdoor or indoor allergens. Outdoor triggers of allergic rhinitis include ragweed, grass, tree pollen, and mold spores. Indoor triggers include dust mites, pet dander, or mold that grows in humid indoor places such as carpets. Outdoor allergens cause seasonal allergic rhinitis (also known as hayfever), that typically occurs during the spring and summer. Indoor allergens can cause pereniall (year-round) allergic rhinitis.
Allergic rhinitis tends to run in families. If one or both parents have allergic rhinitis, there is a high likelihood that their children will also have allergic rhinitis. People with allergic rhinitis have an increased risk of developing asthma and other allergies. They are also at risk for developing sinusitis, sleep disorders (including snoring and sleep apnea), nasal polyps, and ear infections.
Common symptoms of allergic rhinitis include:
- Runny nose or nasal congestion
- Frequent sneezing
- Itchy watery eyes
- Itching in nose, throat, or roof of mouth
Home remedies for allergic rhinitis include nasal wash with a saline solution. Many different over-the-counter and prescription drugs are used to treat allergic rhinitis. These medications include oral and nasal antihistamines, corticosteroid nasal sprays, cromolyn, leukotrine antagonists (such as montelukast [Singulair]), and decongestants. Many of these drugs have side effects. The FDA is currently reviewing whether montelukast causes mood and behavioral changes, including suicidal thoughts. Patients who take this drug should be monitored for these symptoms.
Immunotherapy (allergy shots) may also be an option for some patients.
In addition to avoiding exposure to allergy triggers, people with allergic rhinitis can take precautions to control their environment. These measures include washing animals weekly, using vacuum cleaners and air conditions with high efficiency particulate air (HEPA) filters, frequent washing of bedding and curtains, reducing humidity in the house, and removing sources of mold.
The nose is separated into two passages by a wall of cartilage called the septum. The nasal passages are lined with a membrane that produces a clear liquid called mucus. Mucus is a one of the body's defense systems:
- Moisture from the mucus conditions the air before it reaches the lungs.
- The mucus traps small particles and bacteria, which may enter the nose as a person breathes.
- The trapped bacteria usually do not cause harm in healthy individuals.
- When one side of the nose is congested, air passes through the open (decongested) side. The sides alternate between being wide-open and partly or completely blocked.
If the congestion becomes severe or other changes occur that irritate the nasal passage, rhinitis develops. Rhinitis is inflammation of the nasal passages. To be diagnosed with rhinitis, the patient must experience at least two of the following symptoms for an hour or more on most days:
- Runny nose
- Nasal congestion
- Nasal itching
These symptoms may occur as a result of colds or environmental irritants, such as allergens, cigarette smoke, chemicals, changes in temperature, stress, exercise, or other factors.
Infectious Rhinitis. If symptoms last fewer than 6 weeks, the condition is referred to as acute rhinitis and is usually caused by a cold or infection, or temporary overexposure to environmental chemicals or pollutants. [For more information, see In-Depth Report #94: Colds and the flu.]
Chronic Rhinitis. When rhinitis lasts for a longer period, the condition is called chronic rhinitis. Allergies are often the cause, but structural problems or chronic infections could also be to blame.
Allergic Rhinitis. Allergic rhinitis is rhinitis caused by allergens, which are substances that trigger an allergic response. Allergens involved in allergic rhinitis come from either outdoor or indoor substances. Outdoor allergens such as pollen or mold spores are usually the cause of seasonal allergic rhinitis (also called hay fever). Indoor allergens such as animal dander or dust mites are common causes of year-round allergic rhinitis.
The allergic process, called atopy, occurs when the body overreacts to a substance that it senses as a foreign invader. The immune system works continuously to protect the body from potentially dangerous intruders such as bacteria, viruses, and toxins. However, for reasons not completely understood, some people are hypersensitive to substances that are typically harmless. When the immune system inaccurately identifies these substances (allergens) as harmful, an allergic reaction and inflammatory response occurs.
- The antibody immunoglobulin E (IgE) is a key player in allergic reactions. When an allergen enters the body, the immune system produces IgE antibodies. These antibodies then attach themselves to mast cells, which are found in the nose, eyes, lungs, and digestive tract.
- The mast cells release inflammatory chemical mediators, such as histamine, that cause atopic symptoms (sneezing, coughing, wheezing). The mast cells continue to produce more inflammatory chemicals that stimulate the production of more IgE, continuing the allergic process.
There are many types of IgE antibodies, and each are associated with a specific allergen. This is why some people are allergic to cat dander, while other people are not bothered by cats buts are allergic to pollen. In allergic rhinitis, the allergic reaction begins when an allergen comes into contact with the mucus membranes in the lining of the nose.
Triggers of Seasonal Allergic Rhinitis (Hay Fever)
Seasonal allergic rhinitis occurs only during periods of intense airborne pollen or spores. It is commonly, although inaccurately, called hay fever. No fever accompanies this condition, and the allergic response is not dependent on hay. In general, triggers of seasonal allergy in the U.S. include:
- Ragweed. Ragweed is the most dominant cause of allergic rhinitis in the U.S., affecting about 75% of allergy sufferers. One plant can release 1 million pollen grains a day. Ragweed occurs everywhere in the U.S., although it is less common in western coastal states, southern Florida, northern Maine, Alaska, and Hawaii. The effects of ragweed in the northern states are first felt in middle to late August and last until the first frost. Ragweed allergies tend to be most severe before midday.
- Grasses. Grasses affect people in mid-May to late June. Grass allergies are experienced more in the late afternoon.
- Tree Pollen. Small pollen grains from certain trees usually produce symptoms in late March and early April.
- Mold Spores. Mold spores that grow on dead leaves and release spores into the air are common allergens throughout the spring, summer and fall. Mold spores may peak on dry windy afternoons or on damp or rainy days in the early morning.
Triggers of Perennial (Year-Round) Allergic Rhinitis
Allergens in the House. Allergens in the house can trigger attacks in people with year-long allergic rhinitis, called perennial rhinitis. Household allergens include:
- House dust and mites. Dust mites, specifically mite feces, are coated with enzymes that contain a powerful allergen.
- Pet dander
- Molds growing on wallpaper, house plants, carpeting, and upholstery
Other Causes of Chronic Nasal Congestion
Aging Process. The elderly are at risk for chronic rhinitis as the mucus membranes become dry with age. In addition, the cartilage supporting the nasal passages weakens, causing changes in airflow. In such cases, therapy involves avoiding possible allergens and airborne irritants as well as measures to keep the nasal passages moist. Decongestants are not helpful.
Irritative Rhinitis. Irritative rhinitis is caused by an overreaction to irritants, such as cigarette smoke, dozens of other air pollutants, strong odors, alcoholic beverages, and exposure to cold. The nasal passages become red and engorged. This reaction is not the same as an allergic reaction, although both are associated with increased numbers of white blood cells called eosinophils.
Vasomotor Rhinitis. Vasomotor rhinitis, another type of nonallergic rhinitis, is caused by oversensitive blood vessels and nerve cells in the nasal passages. It occurs in response to irritants, including smoke, environmental toxins, changes in temperature and humidity, stress, and even sexual arousal. Symptoms of vasomotor rhinitis are similar to most of those caused by allergies but eye irritation does not occur.
Blockage in the Nose from Polyps or Structural Abnormalities. A number of conditions may block the nasal passages. Surgery may be helpful for certain cases.
- Polyps. These are soft tissues that develop off stalk-like structures on the mucus membrane. They impede mucus drainage and restrict airflow. Polyps usually develop from sinus infections that cause overgrowth of the mucus membrane in the nose. They do not regress on their own and may multiply and cause considerable obstruction.
- Deviated Septum. A common structural abnormality of the nose that causes problems with air flow is a deviated septum. The septum is the inner wall of cartilage and bone that separates the two sides of the nose. When deviated, it is not straight but shifted to one side, usually the left.
- Other Causes of Blockage. Rarely, cleft palates, overgrowth of bones in the nose, or tumors cause nasal blockage.
Drugs. A number of drugs can cause rhinitis or worsen it in people with conditions such as deviated septum, allergies, or vasomotor rhinitis:
- Overuse of decongestant sprays used to treat nasal congestion can, over time (3 - 5 days) cause inflammation in the nasal passages and worsen rhinitis.
- Other medications that may cause rhinitis include oral contraceptives, hormone replacement therapy, anti-anxiety drugs (particularly alprazolam), some antidepressants, drugs used to treat erectile dysfunction, and some blood pressure medications, including beta-blockers and vasodilators.
- Sniffing cocaine damages nasal passages and can cause chronic rhinitis.
Estrogen in Women. Elevated levels of estrogen appear to increase mucus production and swelling in the nasal passages and can cause congestion. This effect is most apparent in women during pregnancy. In such cases the condition usually clears up after delivery. Oral contraceptives and hormone replacement therapies that contain estrogen have also been associated with nasal congestion in some women.
Allergic rhinitis affects about 50 million Americans of all ages. As with asthma and many upper respiratory infections, the incidence in allergic rhinitis is increasing. Allergies most often appear first in childhood, and allergic rhinitis is the most common chronic condition in childhood, although it can develop at any age. About 20% of allergic rhinitis cases are due to seasonal allergies, 40% to perennial (chronic) rhinitis, and the rest are mixed.
Allergic rhinitis appears to have a genetic component. People with a parent who has allergic rhinitis have an increased risk of developing allergic rhinitis themselves. The risk increases significantly if both parents have allergic rhinitis.
Home or workplace environments can increase the risk for exposure to allergens (mold spores, dust mites, animal dander) associated with allergic rhinitis.
Exclusively breastfeeding for the first 4 months of life can help prevent or delay wheezing and atopic dermatitis in high-risk infants. Some types of infant formulas that are made without cow's milk may possibly help prevent allergies. (There is no evidence that soy-based formulas are helpful.) Solid foods should not be introduced until an infant is 4 - 6 months old. Alterations in a mother's diet do not appear to affect her baby's risk for developing allergies.
Seasonal allergic rhinitis tends to diminish as a person ages. The earlier the symptoms start, the greater the chances for improvement. People who develop seasonal allergic rhinitis in early childhood tend not to have the allergy in adulthood. In some cases, allergies go into remission for years and then return later in life. People who develop allergies after age 20, however, tend to continue to have allergic rhinitis at least into middle age.
Quality of Life
Although allergic rhinitis is not considered a serious condition, it nonetheless can interfere with many important aspects of life. Surveys of nasal allergy sufferers report that symptoms such as feeling tired, miserable, or irritable are present in 50 - 75% of patients. Allergic rhinitis can interfere with work or school performance.
People with allergic rhinitis, particularly those with perennial allergic rhinitis, may experience sleep disorders and daytime fatigue. Often they attribute this to medication, but studies suggest congestion may be the culprit in these symptoms. Patients who have severe allergic rhinitis tend to have worse sleep problems, including snoring, than those with mild allergic rhinitis.
Higher Risk for Asthma and Other Allergies
Asthma and allergies often coexist. Patients with allergic rhinitis often have asthma or are increased risk of developing it. Allergic rhinitis is also associated with eczema (atopic dermatitis), an allergic skin reaction characterized by itching, scaling, and red swollen skin. Chronic uncontrolled allergic rhinitis can worsen asthma attacks and eczema.
Chronic Swelling in the Nasal Passages (Turbinate Hypertrophy)
Any chronic rhinitis, whether allergic or nonallergic, can cause swelling in the turbinate, which may become persistent (turbinate hypertrophy). The turbinate is a tiny shelf-like bony structure that protrudes in the nasal passageways. It helps warm, humidify, and clean the air that passes over it. If turbinate hypertrophy develops, it causes persistent nasal congestion and, sometimes, pressure and headache in the middle of the face and forehead. This condition may require surgery.
Other possible complications of allergic rhinitis include:
- Middle ear infections (otitis media)
- Nasal polyps
- Sleep apnea
- Dental overbite
- Palate malformations caused by mouth breathing
The general symptoms of rhinitis are congestion, runny nose, and postnasal drip, in which mucus drips into the throat from the back of the nasal passage, especially when lying on the back. Symptoms may vary depending on the cause of rhinitis. Symptoms of influenza and sinusitis must also be differentiated from allergies and colds.
Symptoms of allergic rhinitis occur in two phases, early and late.
Early Phase Symptoms. The early phase occurs within minutes of exposure to the allergens and includes:
- Runny nose
- Frequent or repetitive sneezing
- Watery or itchy eyes
- Itching in the nose, throat, or roof of the mouth
Late-Phase Symptoms. The late phase occurs 4 - 8 hours later and may include one or more of these symptoms:
- Nasal congestion and possibly plugged ears. Children may push their nose upward with the palm of their hand or twitch their nose rabbit-like to clear the obstruction.
- Mental changes can include irritability, a slight decrease in attention span, worsened memory, and slower thinking.
- Other common physical symptoms include a decreased sense of smell or taste, plugged ears, sinus headache, postnasal drip or some combination. In severe allergies, dark circles may develop under the eye. The lower eyelid may be puffy and lined with creases.
To determine the cause of allergic rhinitis, the doctor will ask a number of questions about:
- Time of day and year of rhinitis episodes. Rhinitis that appears seasonally is typically due to pollens and outdoor allergens. If symptoms occur throughout the year, the doctor will suspect perennial allergic or non-allergic rhinitis.
- Family history of allergies.
- History of medical problems.
- In women, if they are pregnant or taking drugs that contain estrogen (oral contraceptives, hormone replacement therapy).
- Use of other medications including decongestants, which can cause a rebound effect.
- Any additional unusual symptoms. As examples, bloody nasal discharge and obstruction in only one nasal passage could suggest a tumor. Fatigue, sensitivity to cold, weight gain, and depression may be signs of hypothyroidism.
The doctor will examine the inside of the nose with an instrument called a speculum. This is a painless examination allowing the doctor to check for redness and other signs of inflammation. The doctor will also usually check the eyes, ears, and chest.
Possible physical findings may include:
- Redness and swelling of the eyes
- Swollen mucus membranes in the nose
- Swollen nasal turbinates or nasal polyps
- Evidence of fluid behind eardrum
- Skin rashes
Allergy Skin Tests
A skin test is a simple method for detecting common allergens. Patients are usually tested for a panel of common allergens. Skin tests are rarely needed to diagnose mild seasonal allergic rhinitis, since the cause is usually obvious. The skin test is not appropriate for children younger than age 3.
The procedure is as follows:
- Patients should not take antihistamines for at least 12 - 72 hours before the test. Otherwise an allergic reaction may not show up.
- Small amounts of suspected allergens are applied to the skin with a needle prick or scratch or are injected a few cells deep into the skin. The injection test may be more sensitive than the standard prick test.
- If an allergy is present, a hive (a swollen reddened area) forms within about 20 minutes.
The test is not completely accurate. In most situations, before testing occurs, patients will have tried to avoid any of their known allergens, as well as tried medications, often including nasal corticosteroid sprays. However, patients with more severe symptoms, particularly those with asthma, significant eczema, or nasal polyps, may benefit from earlier skin testing.
Nasal Smear. The doctor may take a nasal smear. The nasal secretion is examined microscopically for factors that might indicate a cause, such as increased numbers of white blood cells, indicating infection, or high counts of eosinophils. High eosinophil counts indicate an allergic condition, but low counts do not rule out allergic rhinitis.
Tests for IgE. Blood tests for IgE immunoglobulin production may also be performed. One test is called the radioallergosorbent Test (RAST), used to detect increased levels of allergen-specific IgE in response to particular allergens. Blood tests for IgE may be less accurate than skin tests. They should be performed only on patients who cannot undergo skin testing or when skin test results are uncertain.
In people with chronic rhinitis, the doctor may also check for sinusitis. Imaging tests may be useful if other tests are ambiguous. CT scans may be useful for some cases of suspected sinusitis or sinus polyps.
In certain cases of chronic or unresponsive seasonal rhinitis, a doctor may use endoscopy to examine for any irregularities in the nose structure. Endoscopy uses a tube inserted through the nose that contains a miniature camera to view the passageways.
If rhinitis symptoms are caused by non-allergic conditions, particularly if there are accompanying symptoms indicating a serious problem, the doctor should treat any underlying disorders. If rhinitis is caused by medications, such as decongestants, the patient may need to stop taking them or find alternatives.
Overall Approaches to Treating Allergic Rhinitis
A variety of items must be considered in selecting a treatment approach. These include:
- Severity of the symptoms
- Frequency (seasonal versus all year, how often during the week)
- Age of patient
- Presence of other related illnesses, such as asthma, atopic eczema, sinusitis, and polyps
- Patient preference regarding types of treatment
- Association with allergens
- Potential and known side effects of medications
- In children, it is important for parents to determine if the child is actually under severe distress and that the parent is not simply responding to their own anxiety when they hear their child snorting or snoring.
Patients with allergic rhinitis have a variety of treatment options available to them:
- Environmental control measures
- Nasal washes may provide good symptomatic relief for some patients.
- Drugs that reduce the inflammatory response are important for preventing moderate or severe allergic rhinitis. Nasal corticosteroids (commonly called steroids) are now considered to be the most effective measure for preventing allergy attacks. Other anti-inflammatory drugs, including leukotriene antagonists and nasal cromolyn, may be tried as second-line medications.
- Antihistamine tablets relieve sneezing and itching and can prevent nasal congestion before an allergy attack, or may be used to treat symptoms. Many brands are available by prescription and over-the-counter.
- Decongestant pills may be used by patients to relieve symptoms. Antihistamine pills may be combined with decongestants. DO NOT USE OVER THE COUNTER DECONGESTANT SPRAYS FOR MORE THAN THREE DAYS AT A TIME.
- Ipratopium bromide nasal spray (Atrovent) does not help with congestion, but may help relieve runny nose.
- Immunotherapy ("allergy shots") may be considered for patients with more severe seasonal allergies that do not respond to treatment. It may also prevent or help manage asthma and the development of new allergies in children.
All drug treatments have side effects, some very unpleasant and, in rare cases, serious. Patients may need to try different drugs until they find one that relieves symptoms without producing excessively distressing side effects.
Treating Seasonal Allergies
Because seasonal allergies generally last only a few weeks, most doctors do not recommend the stronger prescription treatments for children.
- Prescription drugs are required only in severe cases. However, in children with both asthma and allergies, treatments for allergic rhinitis may also improve asthmatic symptoms.
- Patients with severe seasonal allergies should start medications a few weeks before the pollen season and continue taking them until the season is over.
- Immunotherapy ("allergy shots") may be considered for patients with severe seasonal allergies that do not respond to treatment.
Treating Mild Allergy Attacks. Treating mild allergy attacks usually involves little more than reducing exposure to allergens and using a nasal wash. Dozens of treatments are available for allergic rhinitis. Many are available over-the-counter, but some require a prescription. They include:
- Nasal washes
- Intermittent usage of second-generation, nonsedating antihistamines
- Decongestants that relieve nasal congestion and itchy eyes for children over the age of 2 and adults
- Decongestant/antihistamine combinations
Treating Moderate-to-Severe Allergic Rhinitis. Patients with chronic allergic rhinitis or those who have bothersome symptoms that active during most of the year (particularly if they also have asthma) may require daily medications. These drugs include:
- Anti-inflammatory drugs. Nasal corticosteroids are recommended for patients with moderate-to-severe allergies, either alone or in combination with second-generation antihistamines.
- Antihistamines. The second-generation, non-sedating antihistamines -- such as cetirizine (Zyrtec), loratadine (Claritin), fexofenadine (Allegra), or desloratadine (Clarinex) -- cause less drowsiness than older antihistamines, such as Benadryl. They are recommended alone or in combination with nasal corticosteroids for treatment of moderate-to-severe allergic rhinitis.
- Leukotriene-antagonists and nasal cromolyn may be beneficial in specific cases of allergies.
- Immunotherapy ("allergy shots") works well for many patients with severe allergies. It is also proving to reduce asthma symptoms and the use of asthma medications in patients with known allergies.
For mild allergic rhinitis, a nasal wash can be helpful for removing mucus from the nose. You can purchase a saline solution at a drug store or make one at home (2 cups of warm water, a teaspoon salt, pinch of baking soda). Over-the-counter saline nasal sprays that contain benzalkonium chloride as a preservative may actually worsen symptoms and infection.
Simple method for administering a nasal wash:
- Lean over the sink head down.
- Pour some solution into the palm of the hand and inhale it through the nose, one nostril at a time.
- Spit the remaining solution out.
- Gently blow the nose.
Neti pots have also become popular in recent years for prevention and treatment of allergic rhinitis. Nasal irrigation with a saline solution through a neti pot involves:
- Lean over the sink with your head tilted to one side.
- Insert the spout of the neti pot in the upper nostril.
- Slowly pour the salt water into your nose while continuing to breathe through your mouth.
- The water will flow through the upper nostril and out through the lower nostril.
- When the water finishes dripping out, blow your nose.
- Reverse the tilt of your head and repeat the process with the other nostril.
Treating Itchy Eyes
Itching and redness in the eyes sometimes respond to oral antihistamines. Eye drops, however, provide faster relief, and a combination of the two may be best. The following are eye drops for itchy eyes. Others are also available. Individual responses vary, and patients need to find which specific treatment works best for them.
- Antihistamine eye drops: azelastine (Optivar), olopatadine (Patanol), ketotifen (Zaditor), levocabastine (Livostin) for relief of both nasal symptoms and itchy red eyes
- Decongestant eye drops: phenylephrine (Allergan Relief), naphazoline (Naphcon, Opcon-A, VasoClear), tetrahydrozoline (Murine Plus, Visine)
- Combination decongestant/antihistamine: Visine A
- Corticosteroids: loteprednol (Lotemax, Alrex), pemirolast (Alamast)
- Non-steroidal antiinflammatory eye drops: ketorolac (Acular)
General Side Effects and Warnings.
- All eye drops can cause stinging, and some may result in headache and congestion.
- No one should continue taking eye drops if they experience pain, changes in vision, worsened redness, or irritation, or if the condition lasts more than 3 days.
- Do not touch the tip of the device to the eye or touch other surfaces with it. Replace the cap after using. Discard any solution that changes color or becomes cloudy.
- People who have heart disease, high blood pressure, an enlarged prostate gland, or glaucoma should talk to their doctor before taking these types of eye drops.
Histamine is one of the chemicals released when antibodies overreact to allergens. It is the cause of many symptoms of allergic rhinitis. Antihistamines can help relieve:
- Itching, sneezing, and runny nose (unless combined with a decongestant, antihistamines do not work well for relieving nasal congestion).
- Other allergy symptoms unrelated to rhinitis, including hives and some rashes
If possible, patients should take antihistamines before an anticipated allergy attack.
Many antihistamines are available. They include short-acting and long-acting forms, and come in oral pill and nasal spray forms.
Antihistamines are generally categorized as first- and second-generation. First-generation antihistamines, which include diphenydramine (Benadryl) and clemastine (Tavist) cause more severe side effects (such as drowsiness) than most newer second-generation antihistamines. For this reason, second-generation antihistamines are generally preferred and recommended over first-generation antihistamines.
There are some notes of caution when taking any antihistamine:
- Antihistamines may thicken mucus secretions and can worsen bacterial rhinitis or sinusitis.
- Antihistamines can lose their effectiveness over time, and a different one may need to be tried.
Second-generation antihistaminesare sometimes referred to collectively as nonsedating antihistamines. However, cetirizine (Zyrtec) and the nasal spray antihistamines (Astelin, Patanase) can cause drowsiness when taken at recommended doses. Loratidine (Claritin, Alavert) and desloratadine (Clarinex) can cause drowsiness when taken at doses exceeding the recommended dose.
Brand Names. Second-generation antihistamines in pill form include:
- Loratadine (Claritin, Alavert). Claritin is available over-the-counter and is approved for children ages 2 and older. Claritin-D combines the antihistamine with a the decongestant pseudoephedrine. Desloratadine (Clarinex) is similar to Claritin but stronger and longer-lasting. It is available only by prescription.
- Cetirizine (Zyrtec). Zyrtec is approved for both indoor and outdoor allergies. It is the only antihistamine to date approved for infants as young as 6 months. It is available over-the-counter. Zyrtec-D is a pill that combines the antihistamine with the decongestant pseudoephedrine.
- Fexofenadine (Allegra) is also available over-the-counter.
- Acrivastine and pseudoephedrine (Semprex-D) is a pill that combines an antihistamine and decongestant.
Second-generation antihistamines in nasal form are as good as or better than the oral forms for treatment of seasonal allergic rhinitis. However, they can cause drowsiness, and are not as effective for allergic rhinitis as nasal corticosteroids. Nasal spray antihistamines are available by prescription and include:
- Azelastine (Astelin, Astepro)
- Oloptadine (Patanase)
Side Effects and Precautions.
- Common side effects include headache, dry mouth, and dry nose. (These are often only temporary and go away during treatment.)
- Drowsiness occurs in about 10% of adults and in 2 - 4% of children. The nasal spray forms of second-generation antihistamines cause more drowsiness than the pill forms.
- Uncommon side effects include rapid heart beat and chest tightness. Tell your doctor if these effects occur.
- Extended-release forms of Claritin and Zyrtec have other ingredients that can cause other symptoms, including nervousness, restlessness, and insomnia.
Corticosteroids help reduce the inflammatory response associated with allergic reactions. Nasal-spray corticosteroids (commonly called steroids) are considered the most effective drugs for controlling the symptoms of moderate-to-severe allergic rhinitis. They are often used either alone or in combination with second-generation oral antihistamines. The benefits of nasal spray steroids include:
- Reducing inflammation and mucus production
- Improving night sleep and daytime alertness in patients with perennial allergic rhinitis
- Treating polyps in the nasal passages
Nasal-Spray Brands. Corticosteroids available in nasal spray form include:
- Triamcinolone (Nasacort). Approved for children over age 2.
- Mometasone furoate (Nasonex). Approved for use in patients age 3 and older.
- Fluticasone (Flonase, Flounce, Veramyst, generic). Approved for children over age 2.
- Beclomethasone (Beconase, Vancenase). Approved for children over age 6.
- Flunisolide (Nasalide)Approved for children over age 6.
- Budesonide (Rhinocort). Approved for children over age 6.
- Ciclesonide (Omnaris). Approved for patients age 12 and older.
Side Effects. Corticosteroids are powerful anti-inflammatory drugs. Although oral steroids can have many side effects, the nasal-spray form affects only local areas and has less risk for widespread side effects unless the drug is used excessively. Side effects of nasal steroids may include:
- Dryness, burning, stinging in the nasal passage
- Headaches and nosebleed (uncommon but should be reported to your doctor immediately)
Possible Long-Term Complications. All corticosteroids suppress stress hormones. This effect is known to produce some serious long-term complications in people who take oral steroids. Researchers have found far fewer concerns with nasal administration or inhaled forms, but there may be certain problems:
- Effect on growth. The major concern for children is whether nasal steroids, like other forms of steroids, will adversely affect growth. Different steroids may be absorbed differently or may stay longer in the body. Growth impairment from nasal corticosteroid sprays taken at correct dosages has not been demonstrated. Most children who take only recommended dosages of nasal sprays, and do not also take inhaled corticosteroids for asthma, will not have any problems.
- Effect on eyes. Glaucoma is a known side effect of oral steroids. Some ophthalmologists have observed higher pressure in the eye (a sign of glaucoma) in some patients taking nasal steroid sprays, particularly those taking higher dosages or those who also take inhaled corticosteroids for asthma. However, studies to date have not shown an increased risk for glaucoma. Periodic eye examinations are advised.
- Use during pregnancy. Steroids are most likely safe during pregnancy, but pregnant women should talk to their doctors before taking them.
- Nasal passage injury. Steroid sprays may injure the nasal septum (the bony area that separates the nasal passage) if the spray is directed onto it. This complication is very rare.
- Lower resistance to infection. People with any infectious disease or injury in the nose should not take these drugs until the disease or wound has been treated and cured.
Cromolyn serves as both an anti-inflammatory drug and a specific blocker for allergens. The standard cromolyn nasal spray (Nasalcrom) is not as effective as steroid nasal sprays but does work well for many people with mild allergies. It is one of the preferred first-line therapies for pregnant women with mild allergic rhinitis. It may take up to 3 weeks to experience full benefit.
Side Effects. Cromolyn has no major side effects, but minor ones include nasal congestion, coughing, sneezing, wheezing, nausea, nosebleeds, and dry throat. The spray can cause burning or irritation.
Leukotriene antagonists are oral drugs that block leukotrienes, powerful immune system factors that are important in causing airway constriction and mucus production in allergy-related asthma. They appear to work as well as antihistamines for treatment of allergic rhinitis, but are not as effective as nasal corticosteroids. Leukotriene antagonists include zafirlukast (Accolate) and montelukast (Singulair). These drugs are mainly used to treat asthma. Montelukast was approved in 2003 to treat seasonal allergies, and in 2005 to treat indoor allergies. The FDA is currently reviewing these drugs to see whether they are associated with behavior and mood changes, and suicidal thoughts. Patients who take these drugs should be monitored for signs of mood deterioration.
Decongestants work by shrinking blood vessels in the nose. Many over-the-counter decongestants are available, either in tablet form or as nasal or inhaled decongestants that are applied directly into the airways as sprays, drops, or vapors.
Nasal-Delivery Decongestants. Nasal-delivery decongestants are applied directly into the nasal passages with a spray, gel, drops, or vapors. Nasal decongestants come in long-acting or short-acting forms. The effects of short-acting decongestants last about 4 hours; long-acting decongestants last 6 - 12 hours. The active ingredients in nasal decongestants include oxymetazoline, xylometazoline, and phenylephrine. Nasal forms work faster than oral decongestants and may not cause as much drowsiness. However, they can cause dependency and rebound.
The major hazard with nasal-delivery decongestants, particularly long-acting forms, is a cycle of dependency and rebound effects. The 12-hour brands pose a particular risk for this effect.
- With prolonged use (more than 3 - 5 days), nasal decongestants lose effectiveness and can cause swelling in the nasal passages.
- The patient then increases the frequency of the dose. As the congestion worsens, the patient may respond with even more frequent doses.
- This causes dependency and increased nasal congestion.
The following precautions are important for people taking nasal decongestants:
- When using a nasal spray, spray each nostril once. Wait a minute to allow absorption into the mucosal tissues, and then spray again.
- Do not share droppers and inhalers with other people.
- Discard sprayers, inhalers, or other decongestant delivery devices when the medication is no longer needed. Over time, these devices can become reservoirs for bacteria.
- Discard the medicine if it becomes cloudy or unclear.
- DO NOT USE NASAL DECONGESTANTS FOR LONGER THAN THREE DAYS.
Oral Decongestants. Oral decongestants also come in many brands, which have similar ingredients. The most common active ingredients are pseudoephedrine (Sudafed, Actifed, Drixoral) and phenylephrine, sometimes in combination with an antihistamine. Oral decongestants can cause side effects such as insomnia, irritability, nervousness, and heart palpitations. Taking pseudoephedrine in the morning, as opposed to later in the day or before bedtime, can help patients avoid these side effects.
Individuals at Risk for Complications from Decongestants. People who may be at higher risk for complications are those with certain medical conditions, including disorders that make blood vessels highly susceptible to contraction. Such conditions include:
- Heart disease
- High blood pressure
- Thyroid disease
- Prostate problems that cause urinary difficulties
- Raynaud's phenomenon
- High sensitivity to cold
- Emphysema or chronic bronchitis. (Individuals with these conditions should particularly avoid high-potency, short-acting nasal decongestant.)
- Medications that increase serotonin levels, such as certain antidepressants, anti-migraine drugs, diet pills, St. John's wort, and methamphetamine. The combination of these medicines and decongestants can cause blood vessels in the brain to narrow suddenly, causing severe headaches and even stroke.
Anyone with these conditions should not use oral or nasal decongestants without a doctor's guidance. Other people who should not use decongestants without first consulting a doctor include:
- Pregnant women
- Children. Children appear to metabolize decongestants differently than adults. Decongestants should not be used at all in infants and children under the age of 4 years, and some doctors recommend not giving them to children under the age of 14. Children are at particular risk for central nervous system side effects, including convulsions, rapid heart rates, loss of consciousness, and death.
Ipratropium bromide (Atrovent) is a prescription nasal spray that can help relieve runny nose. It works best when given in combination with a nasal corticosteroid. Side effects include nasal dryness, nosebleeds, and sore throat. It should not be used by people who have glaucoma or men who have an enlarged prostate gland.
Immunotherapy (commonly referred to as "allergy shots") is a safe and effective treatment for patients with allergies. It is based on the premise that people who receive injections of a specific allergen will lose sensitivity to that allergen. The most common allergens for which shots are given are house dust, cat dander, grass pollen, and mold.
Immunotherapy benefits include:
- Targeting the specific allergen
- Reducing sensitivity in airways in the lungs as well as in the upper airways
- Preventing the development of new allergies in children
- Reducing asthma symptoms and the use of asthma medications in patients with known allergies. Research suggests it may also help prevent the development of asthma in children with allergies.
Candidates for Immunotherapy. Immunotherapy may be given to anyone over age 7 with allergies that do not get better with medication and who has had a positive allergy test to specific allergans. Immunotherapy is safe for pregnant women who are already receiving it, although half-strength doses are generally recommended, and it should not be started during pregnancy.
Individuals at Risk for Complications. People who should probably avoid immunotherapy include those who have:
- An extreme response to skin tests (this may predict an allergic reaction).
- Uncontrolled severe asthma or lung disease.
- Patients taking certain medications (such as beta-blockers).
- The health status of anyone should be determined before starting treatment.
The major downside to immunotherapy is that it requires a prolonged course of weekly injections. The process generally includes:
- Injections of diluted extracts of the allergen are given on a regular schedule, usually twice a week to weekly at first, then in increasing doses until a maintenance dose has been reached. It usually takes several months and may take up to 3 years to reach a maintenance dose.
- At that time, intervals between shots can be 2 - 4 weeks, and the treatment is continued for another 3 - 5 years.
- Patients can experience some relief within 3 - 6 months. If there is no benefit within 12 - 18 months, discontinue the shots.
After stopping immunotherapy, about a third of allergy sufferers no longer have any symptoms, a third have improved symptoms, and a third relapse.
The use of an injection series is effective, but patients often fail to comply with the regimens. Some other schedules and delivery methods are being investigated that might make the program easier and less distressing.
Rush Immunotherapy. Investigators are studying "rush immunotherapy," in which patients achieve the full maintenance dose with several shots a day over a period of 3 - 5 days. Rush therapy uses modifications that reduce the risk of severe reactions to excessive doses. Studies suggest that it is effective and safe, but anaphylaxis and severe reactions can occur. Patients must be selected carefully and must be monitored closely during this period for severe reactions.
Oral Forms. Trials are underway to test forms of immunotherapy taken by mouth as an alternative to allergy shots. These methods include using a pill taken by mouth or a sublingual (under-the-tongue) tablet. Although oral and sublingual immunotherapy is prescribed in many countries in Europe and South America, it is not approved in the United States and is not considered accepted therapy at this time.
Side Effects and Complications of Immunotherapy
Injections for ragweed and, sometimes, dust mites have higher risks for side effects than other allergy shots. If complications or allergic reactions develop, they usually occur within 20 minutes, although some can develop up to 2 hours after the shot is given.
Side effects of immunotherapy include:
- General itching, swelling, red eyes, hives, soreness at the injection site.
- Less common side effects are low blood pressure, asthma worsening, or difficulty breathing. This is due to an extreme hypersensitivity response called anaphylaxis. It can also occur if excessive doses are given.
- In rare cases, particularly because of excessive doses or if a patient has a serious lung problem, severe reactions can occur, which can be life threatening.
- Premedicating patients with antihistamines and corticosteroids may help reduce the risk of reactions to immunotherapy, although this could mask early warning signs.
People with existing allergies should avoid irritants or allergens. These triggers include:
- Pollen. This is the primary cause of allergic rhinitis.
- Dust mites, specifically mite feces, which are coated with enzymes that contain a powerful allergen. These are the primary allergens inside the home.
- Animal dander (flakes of skin) and hair from cats, house mice, and dogs. House mice are proving to be significant sources of allergens, particularly in urban children.
- Cockroaches are major asthma triggers and may reduce lung function even in people without a history of asthma.
- Some studies suggest that early exposure to some of these allergens, including dust mites and pets, may actually prevent allergies from developing in children.
Indoor Protection against Allergens
Controlling Pets. People who already have pets and are not allergic to them are probably at low risk for developing such allergies later on. When children are exposed to more than one dog or cat during their first year, they have a much lower risk for not only pet allergies but also seasonal allergies and asthma. (Pet exposure does not protect them from other allergens, notably dust mites and cockroaches).
For children who have an existing allergy to pets:
- If possible, pets should be given away or kept outside.
- If this isn't possible, they should at least be confined to carpet-free areas outside the bedroom. Cats harbor significant allergens, which can even be carried on clothing. Dogs usually present fewer problems.
- Washing animals once a week can reduce allergens. Dry shampoos, such as Allerpet, that remove allergens from skin and fur and are now available for both cats and dogs and are easier to use than wet shampoos.
Preventing Exposure to Cigarette and Cooking Smoke. Parents who smoke should quit. Studies show that exposure to second-hand smoke in the home increases the risk for asthma and asthma-related emergency room visits in children. [For help in quitting, see In-Depth Report # 41: Smoking.]
Controlling Dust. Spray furniture polish is very effective for reducing both dust and allergens. Air cleaners, filters for air conditioners, and vacuum cleaners with High Efficiency Particulate Air (HEPA) filters can help remove particles and small allergens found indoors. Neither vacuuming nor the use of anti-mite carpet shampoo, however, is effective in removing mites in house dust. Vacuuming actually stirs up both mites and cat allergens. People with these types of allergies should avoid having carpets or rugs in their homes. For children with allergies, vacuuming should be performed when the child is not around.
Bedding and Curtains.
- Replace curtains with shades or blinds, and wash bedding using the highest temperature setting.
- Encase mattress and pillow in special dust mite proof covers (however, washing is very important since impermeable covers alone do not help prevent allergies).
- Wash pillow in water hotter than 150 F, or in cooler water with detergent and bleach.
- Wash sheets in blankets weekly and hot water.
- Avoid sleeping or lying on cushions or furniture that is cloth covered.
- Stuffed toys should be kept away from the bed and washed weekly as described above. Placing toys in a dryer or freezer may help but is not considered enough.
- Children should sleep as high off the floor as possible (avoid the bottom bunk of a bunk bed).
Reducing Humidity in the House. Living in a damp environment is counterproductive.
- Humidity levels should not exceed 30 - 50%.
- Fix all leaky faucets and pipes, and eliminate collections of water around the outside of the house.
- Dehumidify basements, but empty and clean humidifier daily with a vinegar solution.
- Clean often any moldy surfaces in basement or in other areas of the home.
Exterminating Pests (Cockroaches and Mice).
- Use professional exterminators to eliminate cockroaches. (One study reported that ridding a home of cockroaches and cleaning the house using standard housecleaning techniques failed to eliminate the cockroach allergens themselves.)
- Exterminate mice and attempt to remove all dust, which might contain mouse urine and dander.
- Keep food and garbage in closed containers.
- Keep food out of bedrooms.
Avoiding Outdoor Allergens. The following are some recommendations for avoiding allergens outside:
- Start taking allergy medications 1 - 2 weeks before ragweed season begins. Be sure to take allergy medications before going outside. If regular medications do not work, ask your doctor about allergy shots.
- Camping and hiking trips should not be scheduled during times of high pollen count (May and June for grass pollen and September to October for ragweed).
- Patients who are allergic should avoid barns, hay, raking leaves, and mowing grass. (A mask can be worn during outdoor chores to help reduce pollen exposure.)
- Sunglasses can help prevent pollen from getting into eyes.
- After being outdoors, clean off pollen residue by bathing, washing hair and clothes, and using a nasal salt water rinse.
- Keep doors and windows closed during pollen season.
Some evidence suggests that people with allergic rhinitis and asthma may benefit from a diet rich in omega-3 fatty acids (found in fish, almonds, walnuts, pumpkin, and flax seeds) and fruits and vegetables (at least five servings a day). Investigators are also studying probiotics -- so-called good bacteria, such as lactobacillus and bifidobacterium, which can be obtained in supplements. Some studies have found that probiotics may help reduce allergic rhinitis symptom severity and medication use.
- www.aaaai.org -- American Academy of Allergy, Asthma & Immunology
- www.acaai.org -- American College of Allergy, Asthma & Immunology
- www.niaid.nih.gov -- National Institute of Allergy and Infectious Diseases
- www.njc.org -- National Jewish Medical and Research Center
- www.lungusa.org -- The American Lung Association
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Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.