When we think about chronic sinusitis and how it affects a patient, we typically think about the classic sinonasal symptoms associated with chronic sinusitis. Symptoms such as nasal blockage, nasal drainage, sinus pressure and decreased sense of smell. These sinonasal symptoms are also used to diagnose chronic sinusitis. However, chronic sinusitis can cause problems in the lungs as well. Most common and prominently are symptoms of asthma, such as cough and wheezing. Some studies have suggested that if chronic sinusitis is left inadequately treated, it may even lead to the development of asthma. More frequently, problems arise in patients who have both chronic sinusitis and asthma. First, it is worth understanding that chronic sinusitis and asthma frequently occur together. Some studies suggest that up to 40% of patients with asthma will also have chronic sinusitis. Similarly in patients with chronic sinusitis, around 30-40% of them will have asthma. The common overlap of asthma and chronic sinusitis makes sense from a physiology standpoint because chronic sinusitis and asthma have common inflammatory mechanisms causing them—in other words, if the inflammation is happening in one part of the airway, it would make sense that it could occur in a different part of the airway. I even frequently describe chronic sinusitis to my patients as “asthma of the sinuses”.
In theory, a flare up of either condition could cause a flare up of the other condition but experience suggests that it is more frequently the case that flare ups (or poor control) of chronic sinusitis is causing flare ups (or poor control) of asthma. Our research group is one of the leaders in studying the relationship between chronic sinusitis and asthma, and we have published many scientific studies on the topic. We’ve shown that the severity of chronic sinusitis symptoms very closely correlates with the severity of asthma symptoms that patients may experience. So much so that we can even use the severity of chronic sinusitis to predict which of our asthma patients are experiencing poor asthma control and in need of escalating asthma treatment. We’ve also shown that flares (or acute exacerbations) of chronic sinusitis are highly associated with flares of asthma as well, causing our asthmatic patients to need medications like prednisone that have many side effects and also to miss work and to visit the ER for their asthma. The bottomline is that asthma symptoms and asthma exacerbation is a symptom of chronic sinusitis. Some patients only experience the worsening of their asthma rather than experiencing or noticing the more classic sinonasal symptoms of chronic sinusitis. If you have asthma that is poor controlled or are experiencing frequent flares/exacerbations of your asthma, it is very possible that you also have chronic sinusitis which may be causing the problems with your asthma. On the other hand, if you know that you have chronic sinusitis, be aware that lung problems and asthma symptoms (such as cough, wheezing, shortness of breath, chest tightness) may be a symptom that is being caused by your chronic sinusitis. And finally, if you know that you have both asthma and chronic sinusitis, then understand that a flare up of either inflammatory condition can cause a flare up of the other. This is all the more reason to stay on top of both conditions with an appropriate maintenance treatment regimen.