"Where is the best place to send children to school to avoid pollen?" With the arrival of "allergy season" again, Dr. Yin Jia, chief physician of the Allergy Department at Peking Union Medical College Hospital, encounters parents of allergic patients seeking advice in the outpatient clinic. Allergies can be so severe and persistent that some sufferers even consider relocating, highlighting how distressing allergies can be. But can moving solve allergies? Dr. Yin suggests that relocation can be effective, but she also warns that people who move due to pollen allergies may become allergic to the local pollen again after living in the new area for 5 years or more. According to statistics from the World Allergy Organization, the incidence of allergic diseases has at least tripled in the past 30 years, with a global prevalence rate of 22% currently. Allergies have been listed as one of the six major chronic diseases to be focused on for prevention and control by the World Health Organization in the 21st century. In China, the prevalence of allergies is as high as 27%, with 240 million sufferers of allergic rhinitis alone. Why do people have allergies? Why are there more and more allergy sufferers? How should allergic rhinitis and allergic conjunctivitis be treated? How should the relocation therapy choose a new place to live? Recently, several physicians were interviewed by the "China Science Daily" on these related issues.
The disruption of immune balance is the "culprit"
Is the "culprit" behind allergies the environment or the patients themselves? Dr. Wang Min, chief physician of the Otolaryngology Department at Peking University People's Hospital, believes it's not a simple matter. "Take allergic rhinitis, for example, it has a certain relationship with genetics. If there is a history of asthma, eczema, urticaria, or other allergies among family members, other members are more likely to develop allergic rhinitis." Dr. Wang says that the genetic background does not change significantly in the short term and is a relatively stable social status, but changes in lifestyle are an important factor driving the increase in incidence. "There is a hygiene hypothesis that suggests that people in overly clean environments are more susceptible to allergic diseases, while those who have had infectious diseases in childhood may have a reduced risk of disease. In simple terms, being too clean is not good." Dr. Wang says, "Previously, allergic diseases were considered 'diseases of the affluent,' but as people's living standards have improved, these diseases have become more common." He adds that, in contrast to overly clean environments, exposure to polluted environments, such as contact with PM2.5 and other atmospheric particulate matter, may also trigger allergic reactions in the body. Dr. Wang also mentioned the biodiversity hypothesis. "We should be exposed to various pathogenic microorganisms throughout our lives to train our immune systems to maintain a balanced state. However, phenomena such as being an only child, overuse of antibiotics, drinking formula milk instead of breastfeeding, and an increasing proportion of cesarean sections have reduced the opportunities for individuals to come into contact with pathogenic microorganisms, thereby increasing the likelihood of developing allergic diseases." In addition, he pointed out that psychological factors such as stress are also related factors in causing allergic diseases. "A person may have different allergic manifestations at different ages, which we call the 'allergic march.' For example, eczema and food allergies may occur in infancy, while asthma and allergic rhinitis may develop as one ages." Dr. Wang explains that allergic diseases involve 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 predisposition, it does not mean they will be allergic from birth, but rather that changes in lifestyle gradually disrupt their immune balance, leading to a qualitative change in allergic disease at a certain point in time.
Multiple diseases coexist, making life harder for allergy sufferers
Research has found that the probability of coexisting allergic rhinitis, allergic asthma, and atopic dermatitis, the three allergic diseases, has increased by 9.8 times in the past 40 years. Among adult allergic rhinitis patients, 28% have concomitant asthma, and 24.2% have concomitant atopic dermatitis/eczema, with similar observations in pediatric patients. "Due to the common feature of multiple diseases coexisting in allergic diseases, where multiple diseases influence, exacerbate, and develop with each other, it severely affects the quality of life of patients. This not only increases medical expenses and prolongs treatment periods but also affects the effectiveness of disease control." Dr. Wang says, for example, if allergic rhinitis is not treated promptly, it may trigger other diseases, such as sinusitis, otitis media, obstructive sleep apnea syndrome, as well as food allergies, skin allergies, asthma, and allergic conjunctivitis. Especially asthma, acute attacks may be life-threatening, and improper treatment may eventually develop into chronic asthma, emphysema, or cor pulmonale." For confirmed allergic rhinitis patients, Dr. Wang recommends early drug treatment, such as nasal corticosteroids, antihistamines, and leukotriene receptor antagonists, and also suggests trying desensitization therapy or avoiding allergens to control the condition. "If attacks occur regularly, prophylaxis with nasal spray antiallergic drugs two weeks in advance can be considered." "Ultimately, prevention is better than cure." For the general population, Dr. Wang suggests proper nasal care. For example, do not pluck nose hairs, as this may stimulate the nasal cavity, leading to inflammation and even intracranial infections; do not pick your nose, as this behavior may disrupt the nasal microenvironment and affect its warming, humidifying, filtering, and cleaning functions. When there is secretion in the nasal cavity, physiological saline can be used, and a professional nasal washer can be used to clean the nasal cavity to relieve inflammation. Dr. Wang specifically points out that it is not advisable to cup tap water in the palm and then inhale it through the nose, as tap water lacks osmotic pressure, which may cause discomfort to the nasal mucosa and is not hygienic enough. In addition, when in a polluted environment or in an environment with allergens, wearing a mask should be worn as much as possible to prevent inhaling dust, haze, or allergens. As for the treatment of allergic conjunctivitis, Dr. Tao Hai, chief physician of the Department of Ophthalmology at the People's Liberation Army General Hospital, suggests that patients should first try to identify the allergens as much as possible and then avoid contact with them, combined with drug treatment. He introduced the classification of eye drops currently used to treat allergic conjunctivitis and representative drugs. The first is antihistamine eye drops, such as levocabastine eye drops, etc.; the second is mast cell stabilizers eye drops, such as sodium cromoglicate, pemirolast potassium eye drops, etc.; the third is dual-effect drug eye drops, such as olopatadine eye drops, etc.; the fourth is nonsteroidal anti-inflammatory drug eye drops, such as ketorolac tromethamine eye drops, etc.; the fifth is glucocorticoid eye drops Transplant Therapy: A Boon for Allergy Sufferers?
Recently, during a clinic visit, Dr. Yin Jia encountered a question from a concerned parent: "Where is the best place to send my child to school to avoid pollen?" Dr. Yin explained that if the patient is solely allergic to Chinese juniper, relocating from Beijing might be beneficial, as other cities in China generally have lower densities of juniper trees. However, regions like North America and Japan boast a comparable number of juniper species. For those allergic to Chinese parasol tree pollen, avoiding cities like Nanjing, Shanghai, and Zhengzhou is advisable, as parasol tree pollen allergies can exacerbate asthma. Birch pollen allergy sufferers should steer clear of northern China, Europe, and North America, opting instead for southern China, Australia, Japan, or Singapore. Ragweed pollen allergies necessitate avoiding most northern Chinese cities, with relocation to areas south of the Yangtze River in China, Europe, North America, or Australia potentially alleviating or completely eliminating symptoms. Mugwort pollen allergy sufferers should avoid Korea and Japan, opting instead for southern China, Europe, North America, or Australia.
Dr. Yin also cautions that individuals relocating domestically or internationally due to pollen allergies may develop sensitivities to local pollen after five years or more of residency. For instance, Japanese cedar pollen in Japan, ragweed pollen in North America, grass pollen in Europe, and olive tree pollen in the Mediterranean region could induce symptoms as severe as those experienced previously. Therefore, whether to relocate permanently, semi-permanently, or seasonally depends on individual circumstances and requires careful consideration.
