The common disorder known as vasomotor rhinitis must be distinguished from true allergic rhinitis. This condition shares many of the same symptoms with its allergic counterpart, including stuffy nasal passages, runny nose, and sneezing, but the underlying cause is believed to be, as the name suggests, a vasomotor problem that is, an abnormality of nerve control over blood vessel dilation and constriction. Not uncommonly, it is triggered by physical factors, such as sharp changes in temperature or humidity, as well as by smoke, room odors, and pollution. For some reason even sunshine may precipitate bouts of reflex sneezing in some victims with this condition. Increased nervous tension can likewise play an aggravating role.

Unfortunately, vasomotor rhinitis is chronic and may persist year-round. Treatment is difficult, although in many instances relief may be obtained with the same remedies used to treat its allergic counterpart (as discussed below). Unfortunately, some individuals may have both problems, making matters that much worse.

What Is "Sinus"?
People often refer to sinus, or sinus trouble, to denote chronic headache problems or pain and pressure behind the eyes or cheeks. Others use these terms to describe the nasal stuffiness of hay fever. Sinusitis is the correct medical term for all forms of inflammation involving any of the sinuses.

Everyone has four pairs of sinuses: The frontal sinuses are located above the eyes; the ethmoid sinuses are on the sides of the nose; the sphenoid sinuses are behind the ethmoids; and the maxillary sinuses are behind the cheekbones. All are mucous membrane-lined, air-filled cavities within the skull that lead into the nasal passages. Although their precise function is not known, they are believed to play a role in aerodynamically lightening the skull and in the reception of smells and sounds.

Experts estimate that nearly 70 percent of all chronic sinusitis cases are caused by allergies. Compounding the problem, many of these cases become secondarily infected by bacteria. Contrary to conventional wisdom, sinusitis is not just an adult problem. Children, too, may suffer from "sinus" conditions and their complications.

The headaches characteristic of sinus allergies are believed to be due to a blockage of the openings of the sinuses into the nose, caused by swollen nasal tissue, and the subsequent buildup of pressure in the sinuses. The pain is severest directly over the sinuses, and depending on which of the sinuses is most affected, it may be experienced in the forehead or directly behind or under the eyes. Due to the overnight accumulation of secretions within the sinus cavities and to the diminished ability to clear them, sinus headaches are typically worse when rising in the morning.

To complicate the picture, conditions within chronically allergic sinuses are ripe for bacterial invasion and pus formation. A change from clear to yellowish or greenish nasal secretions suggests bacterial infection. When this happens, sinus symptoms worsen. Postnasal dripping at the back of the throat may occur, additionally giving rise to throat irritation and coughing. More severe cases of sinusitis may be accompanied by fever, muscular aches, and even swelling and tenderness of the skin above the affected areas.