Hay fever

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What is hay fever

What is hay fever

Hay fever, also known as seasonal allergic rhinitis, is an allergic reaction to allergens like molds, pollens, dust mites, insects and animal dander. Hay fever affects millions of people worldwide. Symptoms of hay fever are seasonal. You will feel worse when the pollens that affect you are at their highest levels. Symptoms include sneezing, stuffiness, a runny nose and itchiness in your nose, the roof of your mouth, throat, eyes or ears. These allergic reactions are most commonly caused by pollen and mold spores in the air, which start a chain reaction in your immune system.Sometimes symptoms are caused by molds or flakes of animal skin (dander) from pets. If pollen is the cause, you will feel worse when pollen levels are high.

Pollen comes from flowering trees, grass, and weeds. If you are allergic to pollen, you will notice your symptoms are worse on hot, dry days when wind carries the pollen. On rainy days, pollen often is washed to the ground, which means you are less likely to breathe it.

Allergies that occur in the spring (late April and May) are often due to tree pollen.
Allergies that occur in the summer (late May to mid-July) are often due to grass and weed pollen.
Allergies that occur in the fall (late August to the first frost) are often due to ragweed.

Allergens that can cause perennial (year-round) allergic rhinitis include:

Mold. Mold is common where water tends to collect, such as shower curtains and damp basements. It can also be found in rotting logs, hay, and mulch. This allergy is usually worse during humid and rainy weather.
Animal dander.Proteins found in the skin, saliva, and urine of furry pets such as cats and dogs are allergens. You can be exposed to dander when handling an animal or from house dust that contains dander.
Dust. Many allergens, including dust mites, are in dust. Dust mites are tiny living creatures found in bedding, mattresses, carpeting, and upholstered furniture. They live on dead skin cells and other things found in house dust.

Is hay fever contagious?

Hay fever, also called allergic rhinitis, causes cold-like signs and symptoms, such as a runny nose, itchy eyes, congestion, sneezing and sinus pressure. But unlike a cold, hay fever isn’t caused by a virus. Hay fever is caused by an allergic response to outdoor or indoor allergens, such as pollen, dust mites or tiny flecks of skin and saliva shed by cats, dogs and other animals with fur or feathers (pet dander).

Hay fever lasts longer than a cold or the flu—up to several weeks—and does not cause fever. With hay fever, the fluid from your nose is thin, watery, and clear. With a cold or the flu, the fluid tends to be thicker. Itching (mostly eyes, nose, mouth, throat, and skin) is common with hay fever but not with a cold or the flu. Sneezing happens more with hay fever. Hay fever does not cause fever.

Besides making you miserable, hay fever can affect your performance at work or school and generally interfere with your life. But you don’t have to put up with annoying symptoms. You can learn to avoid triggers and find the right treatment.

Figure 1. Hay fever rash

What causes hay fever?

Allergens cause your body to respond with an allergic reaction. When you are exposed to something you are allergic to, your body releases chemicals. One of theses chemicals is histamine, which is your body’s defense against the allergen. The release of histamine causes swelling, itching, sneezing, runny nose, and watery eyes.

If you are allergic to pollen, you will notice that your symptoms are worse on hot, dry days when wind carries the pollen. On rainy days, pollen often is washed to the ground, which means you are less likely to breathe it.

Hay fever symptoms are most often triggered by tree pollen in the early spring. Grasses are often the culprit during the late spring and early summer. Weeds are most often the cause of late summer and fall hay fever symptoms.

What is pollen?

The word pollen is derived from the Greek word meaning ‘fine flour’. Pollen is the male fertilizing agent (male gametes or sperm cells) of flowering plants, trees, grasses and weeds and the role of the pollen grain is to fertilize the female flower to reproduce plant species. Pollen is also a major allergen that causes symptoms of seasonal allergic rhinitis (hay fever).

Pollen from plants with colorful flowers, like roses, usually do not cause allergies. These plants large, waxy pollen are carried from plant to plant by bees and other insects for fertilization. On the other hand, many trees, grasses and low-growing weeds have small, light, dry powdery pollen that are easily spread by wind. These are the pollen that trigger allergy symptoms.

Each plant has a period of pollination that does not vary much from year to year. However, weather conditions affect pollen levels. For instance, wind and humidity may affect pollen counts. Because pollen are small, light and dry, they can be easily spread by wind, which keeps pollen airborne and carries it over long distances. When the air is humid, such as during or after it rains, pollen becomes damp and heavy with moisture, keeping it still and on the ground. Seasonal allergic rhinitis is often caused by tree pollen in the early spring. During the late spring and early summer, grass pollen often cause symptoms. Late summer and fall hay fever is caused by weed pollen. In warmer places, pollination can be year-round.

Allergy symptoms are often minimal on days that are rainy, cloudy or windless, because pollen does not move about during these conditions. Hot, dry and windy weather signals greater pollen and mold distribution and therefore, increased allergy symptoms.

Pollen grains can be spread by birds, bees or wind:

Some plants (such as flowering plants, including wattle trees) produce small amounts of pollen which are distributed by birds and bees from one plant to another.
Other plants (such as pasture grasses and weeds) rely on the wind to spread their pollen. These pollen are produced in vast quantities, blow long distances and cause allergies in people, even if they live a long way from the source.

Most of the pollen that cause seasonal allergies is produced by airborne pollen from grasses, trees and weeds:

Improved pasture grasses are more allergenic than native grasses.
Pollen from exotic trees, which are planted for their autumn colors, is more allergenic than pollen from native trees.

How long does hay fever last

Pollen seasons can last for several months. For more information you may want to visit the American Academy of Allergy, Asthma & Immunology’s National Allergy Bureau (NAB™) to find information on the current pollen and mold spore levels in your area: http://www.aaaai.org/global/nab-pollen-counts

The National Allergy Bureau currently provides the most accurate and reliable pollen and mold levels from approximately 84 counting stations throughout the United States, one counting station in Canada, and six counting stations in Argentina. The stations use air sampling equipment to collect airborne pollen and spores which are then examined microscopically. This information is also used for research to aid in the diagnosis, treatment and management of allergic diseases.

Pollen counts from the National Allergy Bureau stations are based on actual counts, which reflect the real day to day weather events. Predicted counts reported on many websites may be based on pollen data from previous years and general weather forecasts.

Ragweed Pollen

Ragweed and other weeds such as curly dock, lambs quarters, pigweed, plantain, sheep sorrel and sagebrush are some of the most prolific producers of pollen allergens .

Although the ragweed pollen season runs from August to November, ragweed pollen levels usually peak in mid-September in many areas in the country.

In addition, pollen counts are highest between 5:00 a.m. – 10:00 a.m. and on dry, hot and windy days.

Preventive Strategies

Avoid the outdoors between 5:00 a.m. – 10:00 a.m. Save outside activities for late afternoon or after a heavy rain, when pollen levels are lower.
Keep windows in your home and car closed to lower exposure to pollen. To keep cool, use air conditioners and avoid using window and attic fans.
Be aware that pollen can also be transported indoors on people and pets.
Dry your clothes in an automatic dryer rather than hanging them outside. Otherwise pollen can collect on clothing and be carried indoors.

Grass Pollen

As with tree pollen, grass pollen is regional as well as seasonal. In addition, grass pollen levels can be affected by temperature, time of day and rain.

Of the 1,200 species of grass that grow in North America, only a small percentage of these cause allergies. The most common grasses that can cause allergies are:

Bermuda grass
Johnson grass
Kentucky bluegrass
Orchard grass
Sweet vernal grass
Timothy grass

Preventive Strategies:

If you have a grass lawn, have someone else do the mowing. If you must mow the lawn yourself, wear a mask.
Keep grass cut short.
Choose ground covers that don’t produce much pollen, such as Irish moss, bunch, and dichondra.
Avoid the outdoors between 5:00 a.m. – 10:00 a.m. Save outside activities for late afternoon or after a heavy rain, when pollen levels are lower.
Keep windows in your home and car closed to lower exposure to pollen. To keep cool, use air conditioners and avoid using window and attic fans.
Be aware that pollen can also be transported indoors on people and pets.
Dry your clothes in an automatic dryer rather than hanging them outside. Otherwise pollen can collect on clothing and be carried indoors.

Tree Pollen

Trees can aggravate your allergy whether or not they are on your property, since trees release large amounts of pollen that can be distributed miles away from the original source.

Trees are the earliest pollen producers, releasing their pollen as early as January in the Southern states and as late as May or June in the Northern states.

Most allergies are specific to one type of tree such as:

catalpa
elm
hickory
olive
pecan
sycamore
walnut

or to the male cultivar of certain trees. The female of these species are totally pollen-free:

ash
box elder
cottonwood
date palm
maple (red)
maple (silver)
Phoenix palm
poplar
willow

Some people, though, do show cross-reactivity among trees in the alder, beech, birch and oak family, and the juniper and cedar family.

Preventive Strategies

If you buy trees for your yard, look for species that do not aggravate allergies such as crape myrtle, dogwood, fig, fir, palm, pear, plum, redbud and redwood trees or the female cultivars of ash, box elder, cottonwood, maple, palm, poplar or willow trees.
Avoid the outdoors between 5:00 a.m. – 10:00 a.m. Save outside activities for late afternoon or after a heavy rain, when pollen levels are lower.
Keep windows in your home and car closed to lower exposure to pollen. To keep cool, use air conditioners and avoid using window and attic fans.
Be aware that pollen can also be transported indoors on people and pets.
Dry your clothes in an automatic dryer rather than hanging them outside. Otherwise pollen can collect on clothing and be carried indoors.

Hay fever causes

Your immune system controls how your body defends itself. For instance, if you have an allergy to pollen, your immune system identifies pollen as an invader or allergen. Your immune system overreacts by producing antibodies called Immunoglobulin E (IgE) ¹. These antibodies travel to mast cells that release histamine and other chemicals, causing an allergic reaction that leads to the signs and symptoms of hay fever — such as sneezing, stuffiness, a runny nose, itching and post-nasal drip.

Risk factors for hay fever

The following can increase your risk of developing hay fever:

Having other allergies or asthma
Having atopic dermatitis (eczema)
Having a blood relative (such as a parent or sibling) with allergies or asthma
Living or working in an environment that constantly exposes you to allergens — such as animal dander
Having a mother who smoked during your first year of life

Complications of hay fever

Problems that may be associated with hay fever include:

Reduced quality of life. Hay fever can interfere with your enjoyment of activities and cause you to be less productive. For many people, hay fever symptoms lead to absences from work or school.
Poor sleep. Hay fever symptoms can keep you awake or make it hard to stay asleep, which can lead to fatigue and a general feeling of being unwell (malaise).
Worsening asthma. Hay fever can worsen signs and symptoms of asthma, such as coughing and wheezing.
Sinusitis. Prolonged sinus congestion due to hay fever may increase your susceptibility to sinusitis — an infection or inflammation of the membrane that lines the sinuses.
Ear infection. In children, hay fever often is a factor in middle ear infection (otitis media).

Some people with allergic rhinitis also have asthma. Better control of allergic rhinitis has been shown to result in better asthma control in both adults and children. Emerging evidence shows that untreated allergic rhinitis can also increase the risk of developing asthma.

Prevention of hay fever

There’s no way to avoid getting hay fever. If you have hay fever, the best thing to do is to lessen your exposure to the allergens that cause your symptoms. Take allergy medications before you’re exposed to allergens, as directed by your doctor.

You can help your symptoms by avoiding the things that you are allergic, including:

Keeping windows closed. This is especially important during high-pollen seasons.
Washing your hands after petting animals.
Using dust- and mite-proof bedding and mattress covers.
Wearing glasses outside to protect your eyes.
Showering before bed to wash off allergens from hair and skin.

You can also avoid things that can make your symptoms worse, such as:

aerosol sprays
air pollution
cold temperatures
humidity
irritating fumes
tobacco smoke
wind
wood smoke.

Hay fever symptoms

They vary depending on how bad your allergies are.

Symptoms of hay fever include:

Sneezing and coughing
A runny or blocked nose
Itchy, red, swollen or watery eyes
Itchy throat, mouth, nose and ears
Loss of smell
Pain around your temples and forehead
Headache
Earache
Feeling tired
Dark circles under your eyes
Sore throat

If you have asthma, you might also:

have a tight feeling in your chest
be short of breath
wheeze and cough

Hay fever will last for weeks or months, unlike a cold, which usually goes away after 1 to 2 weeks.

Hay fever season

Your hay fever signs and symptoms may start or worsen at a particular time of year. Triggers include:

Tree pollen, which is common in early spring.
Grass pollen, which is common in late spring and summer.
Ragweed pollen, which is common in fall.
Dust mites, cockroaches and dander from pets can occur year-round (perennial). Symptoms to indoor allergens might worsen in winter, when houses are closed up.
Spoors from indoor and outdoor fungi and molds are considered both seasonal and perennial.

Hay fever diagnosis

If your symptoms interfere with your daily life, see your family doctor. Your doctor will ask you questions about your symptoms and medical history and perform a physical exam. Keeping a record of your symptoms over a period of time can help your doctor determine what triggers your allergies.

Your doctor may want to do an allergy skin test to help determine exactly what you are allergic to. During an allergy skin test, tiny amounts of allergens are applied to your skin. Your doctor will observe and record the way your skin reacts to each allergen.

Your doctor may also decide to do a blood test, such as the radioallergosorbent test (RAST). This test identifies antibodies in your blood that determine what you’re allergic to. Once your allergens are identified, you and your doctor can decide the best treatment.

Your doctor will possibly recommend one or both of the following tests:

Skin prick test. You’re watched for an allergic reaction after small amounts of material that can trigger allergies are pricked into the skin of your arm or upper back. If you’re allergic, you develop a raised bump (hive) at the site of that allergen. Allergy specialists usually are best equipped to perform allergy skin tests.
Allergy blood test. A blood sample is sent to a lab to measure your immune system’s response to a specific allergen. Also called the radioallergosorbent test (RAST), this test measures the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies.

Hay fever treatment

There’s currently no cure for hay fever and you can’t prevent it. But you can do things to ease your symptoms when the pollen count is high.

It’s best to limit your exposure to substances that cause your hay fever as much as possible. If your hay fever isn’t too severe, over-the-counter medications may be enough to relieve symptoms. For worse symptoms, you may need prescription medications.

Many people get the best relief from a combination of allergy medications. You might need to try a few before you find what works best.

If your child has hay fever, talk with your doctor about treatment. Not all medications are approved for use in children. Read labels carefully.

Hay fever medications

Nasal corticosteroids. These prescription nasal sprays help prevent and treat the nasal inflammation, nasal itching and runny nose caused by hay fever. For many people they’re the most effective hay fever medications, and they’re often the first type of medication prescribed.

Examples include fluticasone propionate (Flonase), triamcinolone (Nasacort AQ), mometasone (Nasonex) and budesonide (Rhinocort Aqua). An over-the-counter version (Flonase Allergy Relief) recently became available. A newer prescription nasal spray combines an antihistamine with a steroid (Dymista).

Nasal corticosteroids are a safe, long-term treatment for most people. Side effects can include an unpleasant smell or taste and nose irritation. Steroid side effects are rare.

Antihistamines. These preparations are usually given as pills. However, there are also antihistamine nasal sprays and eye drops. Antihistamines can help with itching, sneezing and a runny nose but have less effect on congestion. They work by blocking histamine, a symptom-causing chemical released by your immune system during an allergic reaction. Over-the-counter examples include loratadine (Claritin, Alavert), cetirizine (Zyrtec Allergy) and fexofenadine (Allegra Allergy). The prescription antihistamine nasal sprays azelastine (Astelin, Astepro) and olopatadine (Patanase) can relieve nasal symptoms. Antihistamine eye drops help relieve eye itchiness and eye irritation caused by hay fever.

Decongestants. These medications are available in over-the-counter and prescription liquids, tablets and nasal sprays. Over-the-counter oral decongestants include pseudoephedrine (Sudafed, Afrinol, others). Nasal sprays include phenylephrine (Neo-Synephrine) and oxymetazoline (Afrin). Oral decongestants can cause a number of side effects, including increased blood pressure, insomnia, irritability and headache. Don’t use a decongestant nasal spray for more than two or three days at a time because it can actually worsen symptoms when used continuously (rebound congestion).

Cromolyn sodium. This is available as an over-the-counter nasal spray that must be used several times a day. It’s also available in eye drop form with a prescription (Crolom). It helps relieve hay fever symptoms by preventing the release of histamine. Most effective when you start using before you have symptoms, Cromolyn sodium doesn’t have serious side effects.

Leukotriene modifier. Montelukast (Singulair) is a prescription tablet taken to block the action of leukotrienes — immune system chemicals that cause allergy symptoms such as excess mucus production. It’s especially effective in treating allergy-induced asthma. It’s often used when nasal sprays can’t be tolerated or when you have mild asthma. Montelukast can cause headaches. In rare cases, it has been linked to psychological reactions such as agitation, aggression, hallucinations, depression and suicidal thinking. Seek medical advice right away for any unusual psychological reaction.

Nasal ipratropium. Available in a prescription nasal spray, ipratropium (Atrovent) helps relieve severe runny nose by preventing the glands in your nose from producing excess fluid. It’s not effective for treating congestion, sneezing or postnasal drip.

Mild side effects include nasal dryness, nosebleeds and sore throat. Rarely, it can cause more-severe side effects, such as blurred vision, dizziness and difficult urination. The drug is not recommended for people with glaucoma or men with an enlarged prostate.
Oral corticosteroids. Corticosteroid pills such as prednisone sometimes are used to relieve severe allergy symptoms. Because the long-term use of corticosteroids can cause serious side effects such as cataracts, osteoporosis and muscle weakness, they’re usually prescribed for only short periods of time.

Other treatments for hay fever include:

Allergy shots (immunotherapy). If medications don’t relieve your hay fever symptoms or cause too many side effects, your doctor may recommend allergy shots (immunotherapy or desensitization therapy). Over three to five years, you’ll receive regular injections containing tiny amounts of allergens. The goal is to get your body used to the allergens that cause your symptoms, and decrease your need for medications. Immunotherapy might be especially effective if you’re allergic to cat dander, dust mites, or pollen produced by trees, grass or weeds. In children, immunotherapy may help prevent the development of asthma.
Under-the-tongue (sublingual) allergy tablets. Rather than getting shots, you have tiny amounts of allergen in pill form dissolve in your mouth, usually daily.
Rinsing your sinuses. Rinsing your nasal passages with distilled, sterile saline (nasal irrigation) is a quick, inexpensive and effective way to relieve nasal congestion. Rinsing flushes out mucus and allergens from your nose. Look for a squeeze bottle or a neti pot — a small container with a spout designed for nose rinsing — at your pharmacy or health food store. Use water that’s distilled, sterile, previously boiled and cooled, or filtered using a filter with an absolute pore size of 1 micron or smaller to make up the saline irrigation solution. Also be sure to rinse the irrigation device after each use with similarly distilled, sterile, previously boiled and cooled, or filtered water and leave open to air-dry.

Hay fever home remedies

It’s not possible to completely avoid allergens, but you can reduce your symptoms by limiting your exposure to them. If you know what you’re allergic to, you can avoid your triggers.

Use over-the-counter hay fever medicines:

antihistamines may ease mild symptoms
a steroid nasal spray may ease a blocked or runny nose
eye drops may help relieve itchy or watery eyes.

Pollen or molds

Close doors and windows during pollen season.
Don’t hang laundry outside — pollen can stick to sheets and towels.
Shower and change your clothes after you’ve been outside to wash pollen off.
Wash your hands, then bathe your eyes with cold water if they are itchy or sore
Avoid smoking or breathing in other people’s smoke, as it can make symptoms worse – see our other article on quitting smoking,
Use air conditioning in your house and car.
Use an allergy-grade filter in your home ventilation system and change it regularly.
Avoid outdoor activity in the early morning, when pollen counts are highest.
Stay indoors on dry, windy days.
Use a dehumidifier to reduce indoor humidity.
Use a high-efficiency particulate air (HEPA) filter in your bedroom and other rooms where you spend a lot of time.
Avoid mowing the lawn or raking leaves.
Wear a dust mask when cleaning house or gardening.
Wear wraparound sunglasses to stop pollen getting into your eyes
Put Vaseline around your nostrils to trap pollen

Dust mites

Use allergy-proof covers on mattresses, box springs and pillows.
Wash sheets and blankets in water heated to at least 130 F (54 C).
Use a dehumidifier or air conditioner to reduce indoor humidity.
Vacuum carpets weekly with a vacuum cleaner equipped with a small-particle or HEPA filter.
Spray insecticide designed to kill dust mites (acaricides) and approved for indoor use on carpets, furniture and bedding.
Consider removing carpeting, especially where you sleep, if you’re highly sensitive to dust mites.

Cockroaches

Block cracks and crevices where roaches can enter.
Fix leaky faucets and pipes.
Wash dishes and empty garbage daily.
Sweep food crumbs from counters and floors.
Store food, including pet food, in sealed containers.
Consider professional pest extermination.

Pet dander

Keep pets out of your home, if possible.
Bathe dogs twice a week, if possible. The benefit of bathing cats hasn’t been proven.
Keep pets out of the bedroom and off furniture.