• E-mail Page

• Animal dander
• Antihistamines
• Decongestants
• Grass
• Histamine
• Nasal corticosteroids
• Pollen
• Pollen count
• Ragweed
• Tree pollen
• Weed pollens

Animal Dander

Some people think that pet allergies are caused by a reaction to hair or fur. But it is actually a protein found in animal dander that causes an allergic reaction. Dander is small, dead skin flakes, or scales, that is shed by animals with fur or feathers.

Dander particles are very small and they travel through the air, where they can easily get into the lining of the eyes or nose, or be inhaled into the lungs. For people who are allergic to dander, symptoms will typically occur quickly, sometimes within minutes after exposure. However, for some people, symptoms become most severe 8 to 12 hours after contact with animals.

Animal dander is extremely common. In fact, a 2004 study found animal dander in 99.9 percent of American homes studied, even though 51 percent of these homes were dog- or cat-free households. Researchers believe this results from the several factors. First, animal dander is difficult to remove completely, as it adheres to surfaces like rugs and walls—so if a cat or dog ever lived in the home, the allergens are likely to still be present.

Second, animal dander is easily transported on clothing, so can be collected at other locations, and brought into a pet-free home. Other studies have found pet allergens in a number of typically pet-free places including schools, trains, buses, hospitals, shopping malls, cinemas, hotels, and even in an allergist's office.

Pet allergies can also be caused by animals' saliva and urine. See more.

Antihistamines

Antihistamine medication blocks the action of histamine during the allergic response. Antihistamines are available over the counter and by prescription. Antihistamines are often used to treat the symptoms associated with allergic rhinitis.

Dander

See Animal Dander.

Decongestants

Decongestants constrict nasal blood vessels, allowing air to more easily pass through the nasal passages, thus helping to relieve congestion. Decongestants can be taken orally or used as nose drops or sprays. Decongestants are used to treat a stuffy nose. Some prescription nasal allergy medicines contain both an antihistamine and a decongestant to treat a range of nasal allergy symptoms.

Grass

Grasses generally release pollen from late spring until early summer. In the southern US, the season begins in February and continues through December. In the North, the grass pollen season begins in May and ends in September. Although more than 1,200 species of grasses are native to North America, only a few are known to cause allergic reactions. Some common grasses that can trigger nasal allergy symptoms are Bermuda grass, Johnson grass, Kentucky bluegrass, Orchard grass, Sweet vernal grass, and Timothy grass. See more.

Histamine

Histamine, a substance released by certain body cells, dilates blood vessels and permeates nearby tissues. When this happens in nasal tissue in response to an allergen, it leads to nasal allergy symptoms.

Nasal Corticosteroids

When taken as prescribed by a doctor, nasal corticosteroids are an effective treatment for nasal allergy symptoms and have a proven safety profile. Natural corticosteroids are hormones secreted by the adrenal glands next to the kidneys. The corticosteroid given to people with nasal allergy symptoms is synthetic cortisol. Corticosteroids have anti-inflammatory properties. The precise mechanism in the treatment of allergic rhinitis is unknown. A nasal corticosteroid is applied directly to the nasal passage.

Pollen

Pollens are tiny reproductive cells found in flowering plants. These microscopic, powdery particles are an important part of plant fertilization, and they are a common trigger of seasonal nasal allergy symptoms. Different plant types have different types of pollen, and some are more problematic for people with allergies than others.

Pollens from plants with bright flowers typically don't trigger allergy symptoms. These larger pollens are carried from plant to plant by bees and other insects. It's the pollens that travel by wind that are the nasal allergy symptom triggers. Trees, grasses and weeds tend to have this type of pollen.

Each plant has a fairly standard timeframe for pollination that doesn't change too much from year to year. However, weather conditions, like wind, can affect the amount of pollen in the air on any particular day.

Depending on the geographical region, the pollen season may start as early as January or February, and typically lasts through October. Trees pollinate first, followed by grasses, and then weeds.

If you notice seasonal nasal allergy symptoms at the same time every year, you may have a pollen allergy. Talk to your doctor about treatment options.

Also see Tree pollens, Weed pollens

Pollen count

A pollen count is a measurement of the amount of pollen in the air, usually reported as grains of pollen per cubic meter of air. The count is typically taken by way of a spinning rod that moves through the air at certain intervals. The pollen grains stick to the rod, allowing researchers to study their types and amounts.

Ragweed

Ragweed is found throughout the US, but is most common in rural areas on the East Coast and in the Midwest. It is a member of the same plant family as the daisy, and flowers in late summer in 6-inch-long spikes at the end of its branches.

• 10-20 percent of Americans are allergic to ragweed, and 75 percent of people with pollen allergies are allergic to ragweed.
• One plant can deliver up to a billion pollen grains in a season.
• Ragweed pollen falls close to the source, but has been found to travel up to 400 miles.
• The plants usually release pollen in late summer to early fall.
• The amount of pollen increases during a warm, dry summer and decreases with a cooler, wet or humid summer.

See other types of weed pollens.

Tree pollen

Trees are the earliest of the seasonal pollen producers, beginning as soon as January in warmer climates, and as late as May or June in cooler areas.

Trees are often problems for people with seasonal nasal allergies, as they release large amounts of pollen, and their pollen can travel long distances.

There are approximately 50,000 types of trees in all, and only a very small number of these (around 100) have been shown to be associated with seasonal nasal allergy symptoms. Most people's allergies are specific to a particular type of tree. Talk to your doctor for help in identifying which one or ones you are reacting to.

Trees that are known to be nasal allergy triggers include the catalpa, elm, hickory, olive, pecan, sycamore, and walnut. See more.

Weed pollens

See Ragweed.