Allergic rhinitis is the set of symptoms that occurs when you breathe in substances you are allergic to. These substances are called allergens and are small proteins.

• Seasonal (intermittent) allergic rhinitis (sometimes called hay fever or rose fever)—This occurs during times of the year when allergens are in the air. Spring and Fall are the most common times. The most common allergen are tree, grass or weed pollens..
• Perennial (persistent) allergic rhinitis—This condition is caused by allergens, such as chemicals, dust, dust mites, cockroaches, animal dander, mold spores, or, occasionally, foods. It may occur any time of year that you encounter these allergens.

An allergic reaction occurs when your body's immune system overreacts to an allergen. When you breathe in an allergen, cells in your nasal passages make a chemical called histamine. Histamine causes your nose to feel itchy and also causes swelling and mucus production in the nasal passages.

These factors increase your chance of developing allergic rhinitis. Tell your doctor if you have any of these risk factors:

• Family members with allergic rhinitis, eczema , or asthma
• Eczema
• Asthma
• Food allergies

Allergic rhinitis can cause the following symptoms:

• Sneezing
• Itching in the nose, eyes, throat, ears
• Red, watery eyes
• Runny nose, nasal congestion
• Sinus pressure
• Postnasal drip and cough
• Headache
• Dark circles under your eyes

Your doctor will try to find out which allergens you are allergic to. You may be referred you to an allergist, if necessary.

Tests may include:

A tiny bit of an allergen is placed under the skin with a needle. The doctor watches to see if the skin in that area becomes red, raised, and itchy. This can be done for multiple allergens at the same time.

To diagnose you, your doctor may ask about your medical history and do the skin prick test. These two diagnostic techniques may

A small sample of blood is taken and tested for different allergens.

You breathe in air containing an allergen. The doctor will watch to see if you have an allergic reaction, such as wheezing or trouble breathing. This test is usually reserved for research settings.

The most effective way to treat allergies is to avoid the allergen. Since this can sometimes be difficult or impossible, other treatments are available.

Treatments may include:

• Antihistamines—stop the interaction between histmamine and the receptors; block the action of histmaine; usually taken as pills or syrup
• Decongestants—decrease congestion by constricting blood vessels, taken as pills or as a nasal spray; use of the nasal spray may lead to rebound congestion
• Mast cell inhibitors—nasal sprays that interfere with the chemical reactions leading to histamine release
• Topical corticosteroids—nasal sprays that decrease swelling in the nasal passages

With immunotherapy, very small amounts of allergens are injected over weeks, months, or even years. The goal is to make your body's immune system less sensitive to those allergens.

There's another, similar type of treatment called sublingual immunotherapy . It involves placing small amounts of allergens under the tongue. This treatment is more popular in Europe. While it has shown to reduce symptoms in some studies, more research is needed.

If you are diagnosed with allergic rhinitis, follow your doctor's instructions .