Allergic rhinitis is an allergy reaction affecting the lining of the nose that may be due to any one of several million different pollens, microscopic animals such as the house dust mite, skin scale or hair particles from animals.
When the sensitive moist membranes that line the nose first come into contact with the sensitizing particle ( an allergen), there is no reaction, but the body’s immune system is primed to react to the next invasion. On the second exposure the large immunoglobulin proteins, which act to defend the body against invasion by any foreign matter, react violently. They cluster around mast cells that rupture and release histamine into the nasal tissues. This causes the tissue to become inflamed. After a few hours or days, the body destroys the histamine released, and the tissues return to normal
When the sensitive moist membranes that line the nose first come into contact with the sensitizing particle ( an allergen), there is no reaction, but the body’s immune system is primed to react to the next invasion. On the second exposure the large immunoglobulin proteins, which act to defend the body against invasion by any foreign matter, react violently. They cluster around mast cells that rupture and release histamine into the nasal tissues. This causes the tissue to become inflamed. After a few hours or days, the body destroys the histamine released, and the tissues return to normal
Antihistamine tablets or nose sprays are used to counteract the histamine released into the tissue and ease the symptoms but some types of antihistamines may cause drowsiness. Steroid nasal sprays or anti-allergy sprays used regularly prevent the nose from reacting to allergens. Allergy shots (immunotherapy) are occasionally recommended if the allergen cannot be avoided and if symptoms are hard to control. Blood or skin tests are performed to determine which allergens cause the allergic symptoms. If a cause can be found, regular injections of the allergen are given in increasing doses (each dose is slightly larger than the previous dose) that may help the body adjust to the antigen. The last resort is surgery in which the anatomical abnormalities are corrected to improve the functions of the nose.
Prevention
Symptoms can sometimes be prevented by avoiding known allergens. During the pollen season, people with hay fever should remain indoors in an air-conditioned atmosphere whenever possible:
- Most trees produce pollen in the spring.
- Grasses usually produce pollen during the late spring and summer.
- Ragweed and other late-blooming plants produce pollen during late summer and early autumn.
