Allergic rhinitis (sometimes called “hay fever”) is one of the most common allergic diseases, affecting about 20-25% of people. It results from an allergic reaction in the nose due to inhaled allergens. Common airborne allergens include pollens from trees, grasses, and weeds, mold spores, or indoor allergens such as pet dander or dust mites. The allergic reaction causes inflammation in the nose that leads to symptoms.
Symptoms of allergic rhinitis are similar to those of a common cold, but unlike the common cold they last more than a few days. The symptoms can last for several weeks during pollen seasons, or can be year-round for people with indoor allergies.
Symptoms vary person to person, but often include:
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A runny nose
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Nasal stuffiness or congestion
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Itching of the nose or eyes
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Post-nasal drip, which is drainage down the back of the throat
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Sneezing
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Children especially may have dark circles under their eyes (allergic shiners) or rub their noses constantly by pushing the nose upward (allergic salute)
Causes of Allergic Rhinitis
There is no way to predict who will develop allergic rhinitis, but young children with eczema (atopic dermatitis) or asthma are at higher risk for eventually developing allergic rhinitis. Allergy is due to a combination of genetic predisposition and environmental triggers.
Allergens are substances that trigger allergies. Pollen is a common allergen. It is a powdery substance produced by flowering plants that is essential for plant reproduction. Most plants are insect-pollinated by bees and these plants do not typically cause allergies. However, 10% of plants are wind-pollinated and these are the plants that cause allergies. Pollen can travel in the air for hundreds of miles and is difficult to avoid.
In Alaska we have a short growing season and the plants have to take advantage of every hour of sunlight. Tree pollen explodes in the spring. Birch is a particularly potent allergen. Other common allergenic trees include alder and cottonwood.
Following trees, grasses pollinate in the summer. Rye and timothy are common Alaskan grasses. Interestingly, many blame summertime allergies on visible cotton flying from the cottonweed trees, but allergic symptoms are actually due to grass pollen in the summer.
Weeds pollinate in the fall, along with increased levels of mold spores due to decaying plant matter.
Indoor allergens, like cat, dog, and dust mites, can cause year-round symptoms.
Our doctors will take a careful history, perform a physical exam, and recommend testing to determine exactly what you are allergic to.
Treatment of Allergic Rhinitis
Avoidance of allergens is the first step for treating your symptoms. Your allergist will offer specific guidance based on what you are allergic to.
Medications are often the next step. Antihistamines work well for those with milder symptoms. Patients with more severe symptoms may need to try a prescription nasal spray.
Finally, allergen immunotherapy (“allergy shots”) is often recommended for patients with moderate to severe symptoms. Other reasons for immunotherapy include: patients who cannot tolerate medications, patients who desire to reduce medication use, or those who are interested in long term control of their symptoms.
Avoidance of Indoor Allergens
Common allergens in the home include dust mites, cats, dogs, and mold. Reducing exposures to these allergens is an important, first step in the treatment of allergies and asthma.
Dust Mites
Dust mites are tiny insects that are invisible to the naked eye that live with people. They are eight-legged arachnids, in the same family as spiders and ticks. They survive by eating organic matter, including human skin flakes. Dust mites are found wherever people reside, especially in our beds, upholstered furniture, and carpets. For water, they require ambient humidity and prefer relative humidity of 50% or greater.
Dust mite allergy is common and is not a sign of having a dirty house. Normal cleaning techniques are not enough to effectively reduce levels of dust mite allergen. The following are some strategies to reduce exposure to dust mites:
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Obtain “dust mite encasements” for the mattress, box spring, and pillows. These covers are specially woven to have a pore size small enough to encase the mites and their allergenic proteins (which are found in their fecal matter).
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Vacuum carpets with a vacuum cleaner that has HEPA filtration.
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Replace carpets with hard floors, if possible.
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Replace upholstered furniture with leather furniture, if possible.
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Reduce indoor humidity, if possible.
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Wash bedding in hot water once a week (130°F will kill dust mites, but it’s dangerous to turn the water heater up this high if children are in the house).
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Minimize stuffed animals – putting the stuffed animals in the freezer periodically kills dust mites.
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Consider a HEPA room air purifier, but dust mite allergen is a larger particle that tends not to be airborne unless disturbed.
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Pets
Many people derive a great deal of enjoyment from their pets. Dogs and cats provide companionship and are often considered a part of the family. However, they are a frequent trigger for allergic rhinitis. People with frequent symptoms of nasal allergies do not realize how much pet allergen contributes to their symptoms.
Cat and dog allergens are proteins secreted from the animal’s skin. There is not really such a thing as a hypoallergenic breed of cat or dog. However, cats produce allergen more consistently than dogs. There can be individual variation on how allergenic a particular dog is, but this is impossible to predict. Cat allergen especially is a very small, sticky protein and studies show that it is present in public places.
The most effective way to avoid cat or dog allergen is to find another home for the pet, but this is often not practical for families. After an animal is removed, allergen still persists in the carpet and furniture for several months.
Other methods of avoiding pet allergen in the home are not terribly effective for preventing symptoms, but it is recommended to keep the pets out of bedrooms, vacuum with a vacuum cleaner with HEPA filtration regularly, obtain a HEPA-filtered air purifier for the bedrooms, and consider removing carpet and putting in hard flooring.
Allergen immunotherapy (“allergy shots”) is a treatment option for cat and dog allergy.
Molds (Fungi) – The most important strategy for avoidance of indoor molds is to avoid water damage, and if it occurs, to remediate it in a timely fashion. Also, avoid having too many houseplants and keep indoor humidity low. HVAC equipment should be inspected regularly.