Patient Education - The Rhinitis-Asthma
by Neil Gershman, M.D.
At the Miami Allergy Journal Club, Dr. Harold Nelson of National Jewish Medical and Research Center gave an update on the Rhinitis-Asthma Link. That is, there is a growing appreciation that rhinitis (inflammation of the nose leading to typical symptoms of runny nose, congestion, sneezing, etc.) is intimately associated with the development and persistence of asthma. Rhinitis, sometimes jokingly referred to as the "Rodney Dangerfield" of chronic diseases, turns out to be a disease to be reckoned with. The following is a brief summary of Dr. Nelson's presentation.
Rhinitis and asthma often occur in the same person. In two long-term studies, rhinitis patients were three times more likely to develop asthma in the future. About 20-30% of rhinitis patients have asthma, while more than 90% of asthmatics have rhintis symptoms.
The first point is that the nasal tissue is very similar to lung tissue. The lining is similar, and the same types of inflammatory blood cells and chemicals collect in both areas. So, it would make sense that the same types of inflammatory or allergic processes might occur in both the nose and lung. But we have the "chicken or the egg" question here, and it seems likely that the nose begets the lung. This is a very important concept, since, if it is true, we should be treating rhintis more aggressively. There are four theories how disease in the nose (rhinitis) can lead to diseases in the lung (asthma).
The first theory is that drainage from the nose, containing inflammatory blood cells and chemicals, drip down into the lungs through the epiglottis. There is some science to back this up, with one x-ray study showing radioactively labeled material (very low, safe amounts) traveling from the nose into the lungs of humans. The amount was very small, however.
The second theory is that an inflamed nose cannot properly condition the air that gets to the lung. That is, the normal process of warming, filtering, and humidifying air is not working as well. This, in turn, can affect the lung.
The third theory involves a reflex connecting the nose and lung, whereby an irritating situation in the nose is transferred by the nervous system to the lung. This is called the vagal reflex.
The last theory is that the inflammatory cells and chemicals in the nose leave the area and travel through the blood to the lungs. There are certain homing mechanisms (like a pigeon) involved that send these materials to there destination in the lung. The truth probably lies in some combination of the above processes.
Lastly, there are a few good scientific studies showing that treatment specific for the nose (nasal steroid sprays, especially) can be quite beneficial for asthma symptoms.
So, the conclusion of all this is that patients and doctors need to appreciate the importance of rhinitis. Not only can rhinitis significantly affect a person's quality of life on it's own, but it can also lead to asthma. It is important that rhinitis is treated aggressively. This should involve both medication and the treatment of allergies if they are present.
Published in May 2002 Newsletter of the Florida Asthma, Allergy & Immuniology Society