Rhinitis, commonly known as a runny nose, is the medical term describing irritation and inflammation of some internal areas of the nose. The primary symptom of rhinitis is nasal dripping. It is caused by chronic or acute inflammation of the mucous membrane of the nose due to viruses, bacteria or irritants. The inflammation results in the generating of excessive amounts of mucus, commonly producing the aforementioned runny nose, as well as nasal congestion and post-nasal drip. According to recent studies completed in the United States, more than 50 million Americans are current sufferers. Rhinitis has also been found to adversely affect more than just the nose, throat, and eyes. It has been associated with sleeping problems, ear conditions, and even learning problems. Rhinitis is caused by an increase in histamine. This increase is most often caused by airborne allergens. These allergens may affect an individual's nose, throat, or eyes and cause an increase in fluid production within these areas.

Types

Rhinitis is categorized into three types: infective rhinitis includes acute and chronic bacterial infections; Nonallergic (vasomotor) rhinitis includes autonomic, hormonal, drug-induced, atrophic, and gustatory rhinitis, as well as Rhinitis medicamentosa; allergic rhinitis, the most common of the three, is an allergic reaction triggered by pollen, mold, animal dander, dust and other similar inhaled allergens.

Vasomotor rhinitis

Vasomotor rhinitis is also known as non-allergenic rhinitis, because it often has the same symptoms as allergies, but has different causes. Whereas allergenic rhinitis conditions (such as hayfever) are the result of the immune system overreacting to environmental irritants (pollen, etc), vasomotor rhinitis is believed to be caused by oversensitive or excessive blood vessels in the nasal membrane. These blood vessels (which are controlled in turn by the autonomic nervous system) contract or dilate in order to regulate mucus flow and congestion. But in the vasomotor rhinitis sufferer, oversensitive or excessive blood vessel dilation or contraction causes an overreaction to such stimuli as changes in weather, temperature, or barometric pressure, chemical irritants such as smoke, ozone, pollution, perfumes, and aerosol sprays, psychological stress and emotional shocks, certain types of medications, alcohol, and even spicy food. Thus, while a normal person's nose may run on a very cold day, a vasomotor rhinitis sufferer's nose may start running (or go completely dry) simply by walking into a slightly colder (or slightly warmer) room, or from eating food that is slightly warmer or cooler than room temperature. While a normal person may tolerate a certain degree of cigarette smoke, the vasomotor rhinitis sufferer may experience significant discomfort from the same level of smoke, etc.

The pathology of vasomotor rhinitis is in fact not very well-understood and more research is needed. Vasomotor rhinitis appears to be significantly more common in women than men, leading some researchers to believe hormones to play a role. In general, age of onset occurs after 20 years of age, in contrast to allergic rhinitis which generally appears before age 20. Individuals suffering from vasomotor rhinitis typically experience symptoms year-round, though symptoms may exacerbate in the spring and fall when rapid weather changes are more common.