Rhinitis, Exercise-Induced

Nose Anatomy and Function

The nose has two passageways, which contain the superior, middle, and inferior turbinates, bones that are lined by the same mucosa that covers the rest of the respiratory system. The mucosal lining contains many blood vessels that help warm and moisten the air that is inspired through the nose. The sympathetic and parasympathetic nerves reach the blood vessels and mucosa of the nose, and according to the message they carry, the blood vessels dilate (parasympathetic) or constrict (sympathetic) and the glands in the lining of the nose secrete fluid (parasympathetic). Other important cells in the mucosa of the nose include mast cells and basophils, which can release the chemicals that cause the symptoms of nasal allergies. Antibodies can also participate in the same release of chemicals from the mast cells and basophils by binding to different allergens in the environment. Several sinuses (ethmoid, sphenoid, and maxillary) and the nasolacrimal duct drain into the nose, and any swelling or distortion of these openings can lead to obstruction of this drainage system so that fluid builds up in the involved sinus. The nose also acts as a filter for polluted air by removing many different-sized particles from the air inhaled.

Physiologic Response to Exercise

During exercise, the release of epinephrine and norepinephrine increases the sympathetic tone, causing constriction of the nasal vessels. This helps to make more room in the nose and decreases airway resistance. Exercise also decreases blood flow to the nose because more blood is redistributed to the working muscles. In addition, the alar dilator muscles (nose muscles) work with each inspiration to increase the opening of the nostrils to allow more inflow of air. Higher-intensity exercise speeds up these physiologic changes. Exercise can decrease airway resistance in the nose by as much as 50%.

Rhinitis in the Athlete

Athletes can complain of fluid draining from their nose for many different reasons. Three categories of rhinitis are allergic, nonallergic, and mimics of rhinitis. Allergic rhinitis is usually seasonal, perennial, or occupational. It involves the athlete being presensitized to a particular allergen. The nasal mucosa with specific antibodies comes into contact with the allergen, resulting in the release of chemicals from the mast cells and basophils. Many different chemicals including histamine are released, causing nasal secretions and postnasal drip, itching, and sneezing. Nonallergic rhinitis includes trauma, environmental triggers that act at the level of the blood vessels to increase permeability and thus cause rhinitis, and infections. There is no specific antibody to allergen needed to trigger the mast cells to release their chemicals. Environmental triggers that can cause rhinitis include temperature or weather changes, cold exposure, particulates in the air, ozone, glues, paints, and cleaners. The common cold is the usual culprit for the new development of rhinitis, which lasts for several days. Conditions that can mimic the symptoms of rhinitis include a deviated nasal septum, nasal tumors, enlarged turbinates, and even less common mimics such as sarcoidosis and Wegener granulomatosis.

...