Allergic Rhinitis

Allergic rhinitis (AR) affects approximately 400 million people worldwide. With prevalence rates between 10% and 30% among adults and over 40% among children.

Since the 1990s the prevalence of AR increased significantly.  The prevalence of AR increased over the years due to several risk factors including global urbanisation and increased levels of environmental pollutants (for example traffic-related pollutants).  Climate changes that prolong pollen season are also a contributing factor).

What is allergic rhinitis (AR)?

AR is a common condition where there is swelling and inflammation in the lining of the nose.  It happens when the nose gets irritated by something you’re allergic to, such as pollen, and the immune system overreacts to allergens.  It is associated with the production of immunoglobulin E (IgE) toward the allergens.  AR can affect the nose, eyes, eustachian tubes, middle ear, sinuses and pharynx.

Signs and symptoms

The word rhinitis means “inflammation of the nose.”

The nose produces fluid called mucus.  This fluid is normally thin and clear.  It helps to keep dust, debris and allergens out of the lungs.  Mucus traps particles like dust and pollen, as well as bacteria and viruses.  Mucus usually drains down the back of your throat.  You’re not aware of this most of the time because it is a small amount and is thin.  When the nose becomes irritated, it may produce more mucus.  The mucus may begin to flow from the front of the nose as well as the back.  Substances in the mucus may irritate the back of the throat and cause coughing.  Postnasal drip occurs when more mucus drains down the back of the throat.

Signs and symptoms of AR include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes.  The fluid from the nose is usually clear.

Types of allergic rhinitis

Allergic rhinitis is caused by allergies to substances called allergens.

Seasonal allergic rhinitis is sometimes called “hay fever.”  It is an allergic reaction to seasonal production of pollen from trees, grasses and weeds.  This type of rhinitis occurs mainly in the spring and fall, when pollen from trees, grasses and weeds are in the air.

Perennial allergic rhinitis is caused by allergens that are present all year long.  The primary causes of this type of rhinitis are allergies to dust mites, mould, animal dander and cockroach debris.

To determine the specific allergen that causes the production of IgE antibodies in AR, laboratory allergen specific tests can be requested.