Chapter 14: Nonallergic rhinitis.

Rhinitis is characterized by one or more of the following nasal symptoms: congestion, rhinorrhea (anterior and posterior), sneezing, and itching. It is classified as allergic or nonallergic, the latter being a diverse syndrome that is characterized by symptoms of rhinitis that are not the result of IgE-mediated events. Excluding infectious rhinitis and underlying systemic diseases, clinical entities that can be classified among the disorders that make up the nonallergic rhinitis syndromes include gustatory rhinitis, nonallergic rhinitis with eosinophilia syndrome (NARES), atrophic, drug-induced (rhinitis medicamentosa), hormone induced, senile rhinitis (of the elderly), rhinitis associated with chronic rhinosinusitis with or without nasal polyps, and the idiopathic variant formerly known as vasomotor rhinitis but more accurately denoted as nonallergic rhinopathy (NAR). The prevalence of nonallergic rhinitis has been observed to be one-third that of allergic rhinitis, affecting ~7% of the U.S. population or ~22 million people. NAR is the most common of the nonallergic rhinitis subtypes, comprising at least two-thirds of all nonallergic rhinitis sufferers. Although certain precipitants such as perfume, strong odors, changes in temperature or humidity, and exposure to tobacco smoke are frequently identified as symptom triggers, NAR may occur in the absence of defined triggers. The diagnosis of nonallergic rhinitis is purely clinical and relies on a detailed history and physical exam. Skin testing or in vitro testing to seasonal and perennial aeroallergens is required to make the diagnosis of nonallergic rhinitis. Because of the heterogeneous nature of this group of disorders, treatment should be individualized to the patient's underlying pathophysiology and/or symptoms and is often empiric.