Abstract
With the evolution of medicine, pathophysiological links among various disease states become increasingly appreciated. In respiratory medicine, epidemiological evidence strongly suggests that upper and lower airway disorders are closely related. The one-airway concept links the common inflammatory processes present in both rhinosinusitis and allergic rhinitis with those seen in asthma. Or to put it a different way, the upper and lower respiratory systems share similar pathophysiological mechanisms, with a linkage between inflammatory influences at both sites.
As otolaryngologists, we must be aware and knowledgeable about the role of inflammation in the nose and sinuses, as well as how disease states in both the upper and lower tract are related. Otolaryngologists need to be familiar with the symptoms and signs of asthma, especially as they relate to comorbid conditions traditionally managed in an otolaryngology clinic.
Epidemiologically, the comorbid conditions associated with allergic rhinitis are acute and chronic rhinosinusitis (with and without polyposis), pharyngitis, laryngitis, snoring and sleep apnea, otitis media with effusion, and asthma. Among rhinitis patients, up to 38% of these individuals are diagnosed with asthma.1 In contrast, up to 78% of asthma patients are diagnosed with rhinitis.1,2 Rhinitis occurs simultaneously or precedes asthma in up to 64% of patients.3 Additionally, the impact of nasal obstruction on asthma has been documented with impact on nasal and mouth breathing.
Prescription data (BCBS 1992–94) also support the link between upper and lower respiratory diseases. Among drugs used for respiratory diseases, in each class (inhaled β-agonists, intranasal steroids, oral steroids, nasal cromolyn), there was a higher percentage of prescription use in those patients with both asthma and allergic rhinitis than among asthma patients alone.
The pathogenesis of asthma involves chronic inflammation, with symptoms such as wheezing and bronchospasm common in acute exacerbation. Similarly, the inflammatory pathways in the upper respiratory tract are also affected by chronic inflammation, with acute symptoms such as sneezing and congestion worse during periods of acute change.
We, as otolaryngologists, commonly diagnose and treat patients with allergic and nonallergic rhinitis and acute and chronic rhinosinusitis. Unfortunately, we routinely underestimate the prevalence of asthma among these patients. It is unusual for us to inquire about symptoms, signs, and behaviors that would suggest the presence of asthma in these individuals. Many of these patients, in fact, may not have a diagnosis to explain their symptoms of cough, shortness or breath, and night-time awakenings. We may be the first physicians that accurately characterize the patient's symptoms as asthma, leading to appropriate and effective treatment.
As specialists in the upper airway, otolaryngologists are therefore in a unique position to recognize, diagnose, and even initiate treatment among patients with lower respiratory diseases such as asthma. Competence in asthma diagnosis is an important component in the otolaryngologist's scope of knowledge. To assure optimal patient care, otolaryngologists need to become increasingly involved in the diagnosis of patients with asthma. We must continue to gain knowledge and expertise in this important area.