Hay Fever / Allergic Rhinitis

Allergic rhinitis is a collection of symptoms, mostly in the nose and eyes, which occur when you breathe in something you are allergic to, such as dust, dander, or pollen.

This article focuses on allergic rhinitis due to outdoor triggers, such as plant pollen. This type of allergic rhinitis is commonly called hay fever.

Causes

An allergen is something that triggers an allergy. When a person with allergic rhinitis breathes in an allergen such as pollen or dust, the body releases chemicals, including histamine. This causes allergy symptoms such as itching, swelling, and mucus production.
Hay fever involves an allergic reaction to pollen. (A similar reaction occurs with allergy to mold, animal dander, dust, and similar inhaled allergens.)
The pollens that cause hay fever vary from person to person and from region to region. Large, visible pollens are seldom responsible for hay fever. Tiny, hard to see pollens more often cause hay fever. Examples of plants commonly responsible for hay fever include:

• Trees (deciduous and evergreen)
• Grasses
• Ragweed

The amount of pollen in the air can play a role in whether hay fever symptoms develop. Hot, dry, windy days are more likely to have increased amounts of pollen in the air than cool, damp, rainy days when most pollen is washed to the ground.
Some disorders may be associated with allergies. These include eczema and asthma.
Allergies are common. Your genes and environment may make you more prone to allergies.
Whether or not you are likely to develop allergies is often passed down through families. If both your parents have allergies, you are likely to have allergies. The chance is greater if your mother has allergies.

Symptoms

Symptoms that occur shortly after you come into contact with the substance you are allergic to may include:

• Itchy nose, mouth, eyes, throat, skin, or any area
• Problems with smell
• Runny nose
• Sneezing
• Tearing eyes

Symptoms that may develop later include:

• Stuffy nose (nasal congestion)
• Coughing
• Clogged ears and decreased sense of smell
• Sore throat
• Dark circles under the eyes
• Puffiness under the eyes
• Fatigue and irritability
• Headache
• Memory problems and slowed thinking

Exams and Tests

The health care provider will perform a physical exam and ask you questions about your symptoms. Your history of symptoms is important in diagnosing allergic rhinitis, including whether the symptoms vary according to time of day or the season, exposure to pets or other allergens, and diet changes.
Allergy testing may reveal the specific substances that trigger your symptoms. Skin testing is the most common method of allergy testing. See the article on allergy testing for detailed information.
If your doctor determines you cannot undergo skin testing, special blood tests may help with the diagnosis. These tests can measure the levels of specific allergy-related substances, especially one called immunoglobulin E (IgE).
A complete blood count (CBC), specifically the eosinophil white blood cell count, may also help reveal allergies.

Treatment

The best treatment is to avoid what causes your allergic symptoms in the first place. It may be impossible to completely avoid all your triggers, but you can often take steps to reduce exposure.
There are many different medications available to treat allergic rhinitis. Which one your doctor prescribes depends on the type and severity of your symptoms, your age, and whether you have other medical conditions (such as asthma).
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 using one cup of warm water, half a teaspoon of salt, and pinch of baking soda.
Treatments for allergic rhinitis include:
ANTIHISTAMINES
Antihistamines work well for treating allergy symptoms, especially when symptoms do not happen very often or do not last very long.

• Antihistamines taken by mouth can relieve mild to moderate symptoms, but can cause sleepiness. Many may be bought without a prescription. Talk to your doctor before giving these medicines to a child, as they may affect learning.
• Newer antihistamines cause little or no sleepiness. Some are available over the counter. They usually do not interfere with learning. These medications include fexofenadine (Allegra), and cetirizine (Zyrtec).
• Azelastine (Astelin) is a antihistamine nasal spray that is used to treat allergic rhinitis.

CORTICOSTEROIDS

• Nasal corticosteroid sprays are the most effective treatment for allergic rhinitis.
• They work best when used nonstop, but they can also be helpful when used for shorter periods of time.
• Many brands are available. They are safe for children and adults.

DECONGESTANTS

• Decongestants may also be helpful in reducing symptoms such as nasal congestion.
• Nasal spray decongestants should not be used for more than 3 days.
• Be careful when using over-the-counter saline nasal sprays that contain benzalkonium chloride. These may actually worsen symptoms and cause infection.

OTHER TREATMENTS

• The leukotriene inhibitor Singulair is a prescription medicine approved to help control asthma and to help relieve the symptoms of seasonal allergies.

Specific illnesses that are caused by allergies (such as asthma and eczema) may require other treatments.
ALLERGY SHOTS
Allergy shots (immunotherapy) are occasionally recommended if the allergen cannot be avoided and if symptoms are hard to control. This includes regular injections of the allergen, given in increasing doses (each dose is slightly larger than the previous dose) that may help the body adjust to the antigen.

References

Updated by: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Stuart I. Henochowicz, MD, FACP, Associate Clinical Professor of Medicine, Division of Allergy, Immunology, and Rheumatology, Georgetown University Medical School (5/25/2009).

References

Wallace DV, Dykewicz MS, Bernstein DI, Blessing-Moore J, Cox L, Khan DA, et al. The diagnosis and management of rhinitis: an updated practice parameter. J Allergy Clin Immunol. 2008 Aug:122(2).

Promote my blog