Nonallergic rhinitis is characterized by sporadic or persistent perennial nasal symptoms that do not result from IgE-mediated immunopathologic events. This reference distinguishes between allergic and nonallergic rhinitis and spans methods to effectively identify, diagnose, and treat these conditions. This source also spans possible causes of nonallergic rhinitis such as fumes, odors, temperature, atmospheric changes, smoke, and other nasal irritants.