The nose, often hailed as the "king of facial features," plays a crucial role not only in one's appearance but also in their health as the gateway to the respiratory system and the starting point of interaction between the body and the external environment.
The seemingly inconspicuous nasal cavity actually constructs multiple lines of defense when facing external stimuli. Dr. Wang Min, Chief Physician of the Department of Otolaryngology Head and Neck Surgery at Peking University People's Hospital, explains that the first line of defense is nasal hair, which prevents dust, insects, and other foreign objects from entering the nasal cavity. The second line of defense is the mucociliary clearance system, where hair-like structures on the nasal mucosa act like brushes, sweeping dust, haze, harmful substances, viruses, bacteria, and other pathogenic microorganisms out of the nasal cavity in an orderly manner. The third line of defense is the sneeze reflex, similar to the cough reflex, which is a defensive command from the central nervous system to expel foreign objects from the nasal cavity. The fourth line of defense is the nasal cavity's immune function, which eliminates harmful substances and protects the nasal cavity through the secretion of specific immunoglobulins and nonspecific lysozymes.
"Breathing is indeed a vital function of the nose, but more importantly, when encountering cold, dry, or polluted air, the nose automatically functions to warm, humidify, or filter and clean the air, thus protecting the overall health of the body," Dr. Wang Min told Chinese Science News.
Inescapable Allergic Rhinitis
When it comes to common nasal diseases, allergic rhinitis is an unavoidable hurdle. Whether in adults or children, allergic rhinitis is increasingly "capturing" more individuals, becoming their "prisoner."
China has as many as 240 million allergic rhinitis patients. According to the "Chinese Guidelines for the Diagnosis and Treatment of Allergic Rhinitis," from 2005 to 2011, the prevalence of allergic rhinitis in Chinese adults increased from 11.1% to 17.6% over six years, with approximately 100 million more people affected. "The population affected by allergic rhinitis is quite extensive and may become more common in the future," said Dr. Wang Min.
Is the culprit behind this primarily environmental or inherent to individuals? Dr. Wang Min believes it might not be singularly attributed. Firstly, allergic rhinitis is somewhat related to genetics. "If there is a history of asthma, allergies, eczema, urticaria, or other allergic conditions in family members, other members are also more likely to develop allergic rhinitis," Dr. Wang Min explained. However, genetic background does not undergo significant changes in the short term and remains a relatively stable social condition. Lifestyle changes are important factors contributing to the increase in incidence.
"There's a hygiene hypothesis suggesting that people are more prone to allergic diseases in overly clean environments, while those who experienced infectious diseases in childhood are less likely to develop allergic diseases. In simple terms, having a germ phobia is not advisable," Dr. Wang Min said. Allergic diseases were previously considered "diseases of the elite," but now, with the improvement of living standards, they are becoming increasingly common. However, he added that corresponding to overly clean environments, exposure to polluted environments, such as contact with PM2.5 and other atmospheric particulate matter, could also trigger allergic reactions.
Dr. Wang Min also mentioned the biodiversity hypothesis. "We should be exposed to various pathogenic microorganisms throughout our entire lifecycle to train our immune system to maintain a balanced state. However, phenomena such as being an only child, overuse of antibiotics, feeding formula milk instead of breastfeeding, and an increasing proportion of cesarean sections have reduced opportunities for individuals to come into contact with pathogenic microorganisms, inadvertently increasing the likelihood of developing allergic diseases," he said, adding that psychological factors such as high-pressure situations are also relevant factors in developing allergic diseases.
"An individual may exhibit different allergic manifestations at different ages, which we call the 'allergy march.' For example, infants may develop eczema and food allergies, while as they age, they may develop asthma and allergic rhinitis," Dr. Wang Min explained. Allergic diseases affect multiple systems, organs, and parts of the body, and may manifest as different target organ symptoms in different environments. Even if a person has genetic predispositions, it does not mean they will be allergic from birth. Rather, it is the disruption of immune balance caused by postnatal lifestyle changes that gradually leads to the onset of allergic diseases at a certain point in time.
Indistinguishable Nasal Inflammation
Allergic rhinitis, sinusitis, and the common cold often leave people unable to distinguish between them, leading to delayed diagnosis and treatment or even misdiagnosis and mistreatment. Many patients end up with minor illnesses turning into major ones, acute conditions becoming chronic, and their lives greatly disrupted.
In this regard, Dr. Wang Min said, "Comparatively, sinusitis is easier to distinguish, mainly presenting as nasal congestion, purulent rhinorrhea, headache, and reduced sense of smell. Allergic rhinitis and the common cold both involve sneezing, runny nose, and nasal congestion symptoms, making them more easily confused."
How to differentiate between allergic rhinitis and the common cold? Dr. Wang Min pointed out that, in terms of etiology, allergic rhinitis is an immune response of the body to external allergens, while the common cold is an infectious disease. In terms of the course of the illness, allergic rhinitis is relatively longer, divided into seasonal and perennial types, while the common cold typically lasts for about a week and is self-limiting. Clinically, allergic rhinitis is characterized by frequent sneezing, sometimes numbering in the hundreds, with thinner nasal discharge, while the common cold has fewer sneezes, and the nasal discharge becomes thicker and more viscous later on. Additionally, allergic rhinitis may be accompanied by other allergic diseases such as allergic conjunctivitis, asthma, food allergies, and skin allergies, while the common cold usually is not. However, allergic rhinitis does not have systemic symptoms, whereas the common cold may present with fever, sore throat, and fatigue.
"The common cold is clinically referred to as acute rhinitis and generally resolves within 7 to 10 days, but some patients may experience prolonged illness, leading to sinusitis. Sinuses are air-filled cavities within the skull bones surrounding the nasal cavity, located above the orbits, medially to the orbits, below the orbits, and below the base of the skull. When the sinus openings are blocked, and pus or secretions accumulate inside, sinusitis occurs. Failure to actively treat allergic rhinitis can also lead to sinusitis, otitis media, asthma, or obstructive sleep apnea," Dr. Wang Min said, emphasizing the interrelatedness and mutual influence among these diseases. Therefore, he advises patients to seek early diagnosis and treatment to avoid life-threatening complications. The increasingly prominent adenoid hypertrophy
With parents paying more attention to children's health and the increasing number of patients with allergic rhinitis, adenoid hypertrophy and adenoid facies are receiving more and more attention.
"Children are in a stage of development where oxygen supply is crucial, but adenoid hypertrophy can block the posterior nasal cavity, leading to difficulties in breathing, symptoms such as mouth breathing, snoring during sleep, breath-holding spells, and even developing adenoid facies characterized by thick upper lips, irregular dental alignment, high arched palate, and vacant expression," said Wang Min. Adenoid hypertrophy not only exacerbates allergic rhinitis but also affects children's attention and hearing due to prolonged oxygen deprivation, leading to secretory otitis media, upper airway cough syndrome, and even impeding their growth in height and weight, severely affecting children's physical and mental health. "Some parents may think their children are just being naughty or unwilling to study, but in fact, this is a state of illness."
However, not all children with adenoid hypertrophy need adenoidectomy. Surgery is only considered for children whose symptoms are not effectively controlled by medication and whose nasal obstruction exceeds two-thirds. Wang Min explained, "Adenoid development is related to age, with adenoids reaching their maximum size around 6 to 7 years old and gradually shrinking thereafter. Therefore, children aged eight or nine with mild symptoms may not necessarily need surgery, as adenoids will continue to shrink with age. However, for children aged four or five with significant clinical symptoms and poor response to conservative treatment, adenoids will continue to grow with age, and we would consider surgical removal at this point."
Healthy noses for a healthy life
The second Saturday of April is National Nasal Health Day in China. However, compared to cancer or trauma, there is a noticeable lack of attention, initiative in seeking medical care, and compliance with treatment for "minor illnesses" such as nasal inflammatory diseases.
In response to this, Wang Min said, "A small nose means big health. The more common and prevalent a disease is, the more attention it deserves. Failure to treat allergic rhinitis in a timely manner can lead to other diseases, such as asthma, which can be life-threatening during acute attacks. Hypertension can also be a trigger for other more serious diseases, so even though the nose is small, the health hazards it can cause are not insignificant."
For healthy individuals, Wang Min recommends proper nasal care. For example, avoid plucking nose hairs, as this cosmetic practice can irritate the nasal cavity and lead to nasal inflammation, potentially causing intracranial infections. Avoid picking the nose, as it disrupts the nasal microenvironment and affects its warming, humidifying, filtering, and cleaning functions. When there is nasal discharge, saline solution can be used, and professional nasal irrigators can be used to clean the nasal cavity and relieve inflammation. Wang Min specifically pointed out that it is not advisable to cup tap water in the palm and inhale it through the nose to clean, as tap water lacks osmotic pressure, which can cause discomfort to the nasal mucosa and is not hygienic enough. Additionally, in polluted environments or where allergens are present, wearing masks is recommended to prevent inhalation of dust, haze, or allergens.
"In fact, many common nasal diseases can be prevented and controlled as long as they are treated early and properly. But ultimately, prevention is better than late treatment, and early treatment is better than early prevention," Wang Min concluded.
