# Allergic Rhinitis

### (Hay Fever; Seasonal Allergies)

## Definition

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, like spring, summer, and fall. The most common allergens are tree, grass, or weed pollens.
  * Perennial (persistent) allergic rhinitis—This condition is caused by allergens that may be present year round. These may include chemicals, dust, dust mites, cockroaches, animal dander, or mold spores. Symptoms may be present any time of year.



## Causes

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 release a chemical called histamine. Histamine causes your nose to feel itchy. Histamine also causes swelling and mucus production in the nasal passages.

Site of Histamine Production  
---  
This area has swelling and increased mucus production after contact with an allergen.  
  
## Risk Factors

Factors that increase your chance of developing allergic rhinitis include:

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



## Symptoms

Allergic rhinitis can cause the following symptoms:

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



## Diagnosis

Your doctor will try to find out which allergens you are allergic to. You may be referred to an allergist or immunologist. This is a doctor who specializes in allergies.

Tests may include:

#### Skin Prick Test

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.

#### RAST Testing

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

#### Provocation Testing

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.

## Treatment

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:

#### Medications

Your doctor may advise: 

  * Nasal sprays 
    * **Note** : Using a nasal spray may lead to rebound congestion.


  * Antihistamines to block the action of histamine
  * Decongestants to decrease congestion 



#### Immunotherapy

With immunotherapy, 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. This treatment may be effective in reducing or eliminating the symptoms of allergic rhinitis.

Sublingual immunotherapy may also be used. This type of treatment involves putting the allergic substances under the tongue, rather than using allergy shots. 

## Prevention

The following strategies may help prevent allergic rhinitis : 

  * Stay inside during the morning hours when pollen counts are highest.
  * Avoid outside activities during the time of year when the trees, grasses, weeds, or molds are blooming.
  * Keep the windows of your house and car closed to keep pollen out.
  * Use an air conditioner to reduce indoor humidity and to prevent mold and mildew growth.
  * Clean your air conditioner's filters regularly.
  * Consider running an air purifier in your home, especially in your bedroom.
  * Use vacuum cleaners and air conditioners with HEPA filters to trap allergens.
  * Decrease or avoid outdoor activities on hot summer days, when ozone levels may make your symptoms worse.
  * Wash bedding weekly in very hot water.
  * Use fewer dust-collecting items, such as curtains, bed skirts, carpeting, and stuffed animals, especially in your bedroom.
  * If you can't avoid having a pet with fur, vacuum frequently and keep your pet out of bedrooms and other rooms with carpets.



## RESOURCES

American Academy of Allergy, Asthma, and Immunology http://www.aaaai.org 

Asthma and Allergy Foundation of America http://www.aafa.org 

## CANADIAN RESOURCES

Allergy Asthma Information Association http://aaia.ca 

Health Canada http://www.hc-sc.gc.ca 

## References

Allergic rhinitis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated October 24, 2012. Accessed October 31, 2012. 

Allergic rhinitis (hay fever). American College of Allergy, Asthma, & Immunology website. Available at: http://www.acaai.org/allergist/allergies/types/rhinitis/Pages/default.aspx. Accessed August 18, 2014. 

Rhinitis. American Academy of Allergy Asthma & Immunology website. Available at: http://www.aaaai.org/conditions-and-treatments/allergies/rhinitis.aspx. Accessed August 18, 2014. 

8/11/2006 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Durham SR, Yang WH, Pedersen MR, et al. Sublingual immunotherapy with once-daily grass allergen tablets: a randomized controlled trial in seasonal allergic rhinoconjunctivitis. J Allergy Clin Immunol. 2006;117:802-809. 

8/27/2013 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Kim JM, Lin SY, Suarez-Cuervo C, et al. Allergen-specific immunotherapy for pediatric asthma and rhinoconjunctivitis: a systematic review. Pediatrics. 2013 Jun;131(6):1155-67.