In recent years, allergic rhinitis (also known as allergic rhinitis) has undergone profound changes in etiology, epidemiology, incidence, clinical manifestations, etc. The medical profession has also gained a new understanding of the relationship between allergic rhinitis and bronchial asthma (hereinafter referred to as “asthma”) and has put forward some new concepts.
Allergic rhinitis and asthma are common combined diseases. The upper and lower respiratory tracts are connected and the mucous membranes are continuous, so any part of the respiratory tract that suffers some kind of stimulation, such as allergens, pollutants, viruses, bacteria, etc., can produce similar reactions.
Allergic rhinitis and asthma are not separate diseases; they often coexist in an interdependent manner in the same patient. Upper respiratory tract allergic diseases and asthma represent aspects of a “single inflammatory airway syndrome”, so it has been suggested that they be called “allergic rhinosinus-sinus-pharyngeal-ear-bronchitis” or “allergic rhinotracheitis “. Respiratory allergic disease may be a systemic disease, because the upper or lower respiratory excitation test with pollen can lead to an inflammatory response at the other end of the respiratory tract, i.e., the lower respiratory tract (bronchial) excitation test can cause inflammation of the nasal mucosa, while the nasal mucosa excitation test can cause inflammation of the lower respiratory tract. Therefore, it is also believed that such patients should be called as suffering from respiratory allergic reactions without the need to distinguish whether they suffer from allergic rhinitis or asthma.
The upper respiratory tract is the first line of defense of the respiratory system against airborne particles and irritants. The nasal cavity is the “guardian” of the lower respiratory tract, like an air filter and regulator, providing the most appropriate air for the lower respiratory tract. When the nasal mucosa is irritated or diseased, changes in nasal function can have a direct or reflex effect on the lower respiratory tract, triggering asthma.
Most patients with allergic rhinitis do not have asthma, while most asthmatic patients have allergic rhinitis. About 80% of case reports with both asthma and allergic rhinitis show that allergic rhinitis precedes or coincides with asthma, suggesting that asthma is an extension of allergic rhinitis or that allergic rhinitis can “advance” to asthma.
Given that allergic rhinitis and asthma are different manifestations of the same disease in the upper and lower airways, most scholars classify allergic rhinitis and asthma as a disease taxonomy of total airway inflammatory hyperresponsive syndrome. They can be divided into three stages: 1) allergic rhinitis without bronchial hyperreactivity or asthma; 2) allergic rhinitis with bronchial hyperreactivity, but without asthma; 3) allergic rhinitis with asthma.
These three stages only reflect the different severity of the syndrome. Once asthma is established, the bronchial hyperreactivity manifests itself in a persistent form.
Rhinitis – a risk factor for asthma The prevalence of asthma in patients with allergic rhinitis is 20% to 40%, which is considerably higher than the 2% to 5% in the normal population; therefore, the risk of asthma in patients with allergic rhinitis is 8 to 20 times higher than in the normal population. A significant number of asthma patients have allergic rhinitis symptoms before asthma attack, and if effective treatment measures for allergic rhinitis are taken in time, asthma attack can be avoided.
Since allergic rhinitis is a risk factor for asthma, allergic rhinitis is no longer an isolated disease but a complex syndrome, which is a systemic disease and is caused by abnormal immune function of the body. Therefore, treatment should be systemic and localized, so as to prevent asthma and control nasal inflammation.