One of these involves specific protein and chemical reactions within the body and is called the allergic response. This specific mechanism can affect any area of the body where a foreign substance is encountered. One of the principal functions of the nose is to remove particles from the air before it goes into the lungs. These particles become trapped in the mucus lining of the nose and are subsequently destroyed. Because of the amount of foreign material processed in the nose, the allergic response can become quite noticeable and troublesome.
Histamine is one of the principal chemicals involved in the allergic response.
It is responsible for many of the symptoms of allergy, including swelling, itchiness, and sneezing. It can also cause the overproduction of mucus, leading to a runny nose. This is the reason that anti histamines, drugs that block the action of this chemical, are often used in treating allergies. Other methods of therapy include nasal steroid sprays or cromolyn nasal sprays. Common allergens are dust mites, proteins from pet fur called dander, molds, and pollen.