Allergic Rhinitis and Asthma
• Asthma is defined as a heterogeneous disease characterized by chronic airway inflammation culminating in respiratory symptoms such as wheezing, shortness of breath, chest tightness, and cough.
• Studies have suggested that asthma and allergic rhinitis are connected, with over 80% of asthmatics concurrently diagnosed with rhinitis; patients with allergic rhinitis are three times more likely to develop asthma than the general population. These studies have shown that asthma patients who also have allergic rhinitis tend to have an increased disease burden; in addition, treatment of the rhinitis may inhibit or totally prevent the development of asthma.
• The World Health Organization has recommended in its guidelines that any patient diagnosed with allergic rhinitis be screened for asthma via history and physical exam; those found to have severe allergic rhinitis should be referred for formal pulmonary function evaluation.
• Even those found to have either allergic rhinitis or asthma have an increased eosinophilic infiltration in the other site.
• In addition, the sinonasal cavity mucosa and inflammatory process is similar to that of the respiratory mucosa; both of these processes involve similar cytokines such as IL-4, 5, and 13.
• Studies have revealed that topical nasal corticosteroids, such as fluticasone, will help to reduce bronchospasms and asthma-related ED visits and hospital admissions in asthmatics diagnosed with allergic rhinitis. Similarly, orally inhaled steroids will reduce eosinophilic inflammation of the nasal mucosa.
Chronic Rhinosinusitis and Asthma
• A relationship between chronic rhinosinusitis and asthma exists in that both diseases are characterized by a Th2 type immunologic response, in which inflammation in one location of the airway leads to increased inflammation in another.
• Samter’s triad is a notable example of the relationship between chronic rhinosinusitis, polyposis, and asthma. It has been shown that, in these patients, functional sinus surgery leads to improvement in asthma symptoms.