Allergic rhinitis is caused by the body’s immune response to an environmental trigger.
Other less common types of rhinitis include:
In atrophic rhinitis, the natural mucosal membrane is thinned out and the glands that secrete mucus and participate in mucus clearance are lost. This leads to secondary infections and persistent crusting of the nose.
This is a rare condition that occurs in those who have undergone aggressive surgery to the nasal cavities.
Vasomotor rhinitis is a condition where there is chronic rhinitis in the absence of an identifiable allergy.
Dilation of blood vessels in the nose is partly controlled by the autonomic nervous system. It is believed that an oversensitivity of this autonomic nervous system can cause vasomotor rhinitis. In some cases, the trigger may be a change of temperature or the presence of a chemical stimulant like strong perfume or chemical fumes.
These occur after exposure to the allergen. For example, walking into a dusty room may cause such symptoms to develop.
There is often a history of other allergies and sensitive skin and some people may also have asthma.
skin prick test may be able to identify the offending allergen (substance that triggers the allergic response). It is a simple test performed in the clinic.
In a skin prick test, a small area of skin, usually on the forearm is used to test for allergies to various allergens. A small amount of allergen is then applied to the skin and the area observed for a positive reaction.
By identifying the allergen, severe or recurrent attacks can be reduced by avoiding or minimising subsequent exposure to the allergen. Common allergens include dust mites and pollen.
Treatment of allergic rhinitis is aimed mainly at reducing the severity and frequency of attacks.
Methods of management can be divided into :
Changes to the living environment will have to be made to avoid the allergens that trigger attacks. For example, frequent cleaning of living areas and replacing items such as carpets or stuffed toys may reduce the amount of exposure to dust mites in the house.
Medical therapy is directed at controlling symptoms and reducing the allergic response.
In cases where symptoms are
intermittent, antihistamines may be
prescribed. Where attacks are frequent,
a nasal steroid may also be added.
Nasal steroids are widely used because
they are effective for long-term control
of symptoms and are safe for long-term
use as they have a topical action and
very little of the steroid actually gets
absorbed by the body.
Surgical therapy. Surgical therapy may
be useful where there are anatomical
abnormalities such as a deviated
nasal septum, or inferior turbinate
Surgery may improve the symptoms
of congestion and blockage, but may
not have any impact on the other
symptoms such as runny nose or itchy
eyes. Nasal steroids may still have to be
used to control these symptoms.
It is also suitable for a select group of people with severe, prolonged symptoms that do not respond to conventional therapy.
In immunotherapy, the body’s immune system is modulated to reduce the response to the allergen, thus reducing the severity of symptoms. This is a slow process and will require injections or self-administered drops taken regularly over a period of 1 to 3 years.