Upper Airway Disease
Upper airway disease incorporates rhinitis, sinusitis, and rhinosinusitis, all of which are associated with postnasal drip. Allergic rhinitis is the most common form of rhinitis, affecting approximately 20% of adults and over 30% of children. Nonallergic rhinitis also affects a large number of people, usually adults more than children. The lack of specific diagnostic criteria for nonallergic rhinitis limits epidemiologic studies. Overlap of allergic and nonallergic rhinitis is also common and is termed mixed rhinitis by some authors. Sinusitis is more likely in individuals with rhinitis, and chronic sinusitis is coincident with nasal inflammation, leading to the term rhinosinusitis.
Upper airway symptoms also may result from anatomic issues related to the upper airway, such as adenoid hypertrophy and nasal septal deviation. In addition, symptoms may result from nasal polyposis, usually with rhinosinusitis. Polyposis is generally associated with nonallergic rhinitis, though not exclusively.
Relationship With Asthma
Asthma is almost always associated with nasal disease, in up to 95% of cases in some studies. This association is allergic rhinitis in individuals with allergic asthma and nonallergic rhinitis in nonallergic asthma. Chronic rhinosinusitis is frequently linked to persistent, severe asthma, as is nasal polyposis.[7,9,10] Treatment of the upper airway disease improves asthma for a variety of reasons. Ideal management of asthma is generally not achieved without control of upper airway disease.
Rhinitis may also precede the diagnosis of asthma with the relative risk of subsequent asthma development increased by 2.7–3.5 in a study of 6461 adults, aged 20–44 years. Rhinitis also may precede severe rhinosinusitis, nasal polyposis, and asthma associated with nonsteroidal anti-inflammatory drugs. The mechanism linking the development or exacerbation of asthma in individuals with upper airway disease may be multifactorial, including release of systemic immune mediators from the upper airway, drainage of inflammatory mediators from the upper airway into the lower airway, neurogenic responses resulting in more generalized airway inflammation or common inhalant mechanisms with allergens causing inflammation initially in the upper airway followed by lower airway involvement. Inflammation develops in the nasal airway following select allergen bronchial challenge in allergic patients and vice versa.[12,13] All of these mechanisms may be involved or the mechanism may vary with differing types of rhinitis or rhinosinusitis.
Diagnostic and Therapeutic Considerations
The primary symptom of rhinitis or rhinosinusitis likely confused with asthma is cough. This is a particular challenge because almost all persistent asthmatic patients have rhinitis or rhinosinusitis and cough is a frequent problem with asthma as well. Persistent asthma can suggest that greater consideration be given to optimal management of the upper airway disease. Utilization of systemic therapies, such as oral leukotriene modifiers, allergen immunotherapy or omalizumab, and allergen avoidance, may simultaneously address the treatment of both the upper airway and asthma. Sleep disturbance, a common comorbidity with asthma, is also a complication of persistent nasal obstruction.
Curr Opin Allergy Clin Immunol. 2013;13(1):78-86. © 2013 Lippincott Williams & Wilkins