Aberrant immunity

Extremely common allergic rhinitis is an inadequate immune response. At the origin of these often very troublesome conditions, many allergens may be involved. Mites, cockroaches, pollens ... who are our enemies?

Causes of allergic rhinitis

You sneeze and you blow your nose as soon as spring arrives? Or maybe your nose runs throughout the year without you having a cold? You are probably suffering from allergic rhinitis. In 30 years, the frequency of these allergies has doubled and it is now estimated that 10 to 15% of people in industrialized countries suffer to varying degrees from this disorder. This upsurge seems not so much related to external pollution as to the increasing confinement of dwellings. Insulation of homes has the effect of increasing the density of domestic allergens, such as cleaning agents or dust mites, inside dwellings.

Like all allergies, allergic rhinitis is linked to an abnormal immune response of the organism to a substance (allergen) to which the person has become sensitive. During this first phase of sensitization, the individual produces specific antibodies, IgE, which specifically recognize the allergen involved.

These antibodies will bind to certain cells of the mucous membranes, in particular nasal. Then, during a new contact with the allergen, this one will be able to meet the cells carrying these IgE (the mast cells) and to stimulate them, causing the release of inflammatory factors. It is this inflammatory reaction which causes the characteristic disturbances: aqueous nasal discharge, tingling, sneezing, sometimes associated with tearing and loss of smell.

The condition usually begins in childhood or early adulthood, and can disappear with aging. It is not serious in itself, but can become very troublesome, resulting in insomnia and fatigue.

There are two forms of allergic rhinitis

However, polysensitizations are frequent and one person may very well have a perennial allergy to cat hair and a seasonal allergy to pollens. In children, allergic rhinitis can also be linked to food allergens.

All chronic rhinitis is far, however, from being allergic. More than half of them are related to another cause. In particular, vasomotor rhinitis is often linked to the abuse of certain drugs (especially nasal vasoconstrictor).

This condition reflects an allergic (or atopic) terrain, as evidenced by the frequent association of rhinitis with other allergic diseases, such as asthma or eczema. The origin of this allergic predisposition is certainly multifactorial, with an hereditary genetic component. Thus, people with one or both parents with an allergic disease are more likely to develop an allergy in the form of a rhinitis in particular.

The seasonal rhinitis (the classic "hay fever") very often due to a pollen allergy The perennial rhinitis persist throughout the year and are generally related to domestic allergens such as mites, cockroaches or hairs of domestic animals .