BEIJING, April 3 (Xinhua) -- As an allergist who also suffers from pollen allergies, Li Lisha is keenly aware of the arrival of pollen season. The blast of wind that makes the Associate Professor of the Allergy Department of Peking Union Medical College Hospital (PUMCH) sneeze reminds her that pollen season has come again.
Every year from early March onward, the consulting rooms and corridors echo with the sound of patients sneezing one after another. While administering medication to herself, Li also prescribes treatments for her patients.
"Over the years, I have clearly observed a growing number of patients suffering from pollen allergies," said Li. During each pollen season, 70 to 80 percent of patients in her clinic seek help for pollen allergy-related symptoms.
Research has shown that over the past two decades, the prevalence of pollen allergies in China has been steadily increasing, she said.
A community-based door-to-door survey led by the Allergy Department of PUMCH, in collaboration with 16 sub-centers across China, shows that the current prevalence of allergic rhinitis is 4.2 percent, the highest among the eight allergic diseases surveyed.
Among the patients Li has treated, the prevalence of pollen allergies can exceed 18 percent in regions north of the Yangtze River, particularly in the northwestern grasslands, with some localities reporting rates exceeding 30 percent.
In contrast, the prevalence remains relatively low in southern cities such as Shanghai and Guangzhou. This regional disparity is closely linked to the localized distribution of allergenic plant species.
It is of great significance to know the specific triggers of pollen allergies for both targeted protection and treatment, said Li. On the one hand, patients can more precisely avoid the pollen they are allergic to based on pollen forecasts. On the other hand, such knowledge also enables more tailored therapeutic interventions.
At present, PUMCH is leading the development of a large-scale data platform for clinical research on allergic diseases, aiming to support clinical decision-making.
To identify exactly which type of pollen a patient is allergic to, Li and her colleagues have been engaged in the research, development and production of allergen preparations. To date, they can perform skin-test diagnoses for more than 30 types of pollen.
Currently, eight types formulated for medical institutions have been distributed to more than 50 hospitals nationwide for clinical use.
Their findings indicate that simply doubling the dose of antihistamines is less effective than combining them with nasal spray hormones. In the later stage of the pollen season, appropriately reducing the dosage in response to declining pollen concentrations helps control symptoms.
Many patients become alarmed at the mere mention of "hormones" and would rather endure the symptoms than use nasal sprays, said Li.
"In fact, intranasal corticosteroids are a topical treatment with minimal systemic absorption and a strong safety profile, making them one of the most effective therapies for hay fever currently available," she explained. On the contrary, long-term avoidance of medication can lead to recurrent symptoms, which may in turn cause complications such as sinusitis and otitis media.
"For patients whose symptoms fluctuate rapidly, adjusting the treatment regimen every two to three days yields better outcomes than a fixed weekly adjustment," said Li.
In addition, they have recognized that starting preventive medication two weeks before the pollen season can significantly delay symptom onset and reduce severity, compared with initiating treatment only after symptoms have developed.
These seemingly minor adjustments in medication strategies can, in fact, greatly improve patients' quality of life and reduce unnecessary drug use, according to Li.
"Is there a way to cure it completely?" This is a question Li is frequently asked by patients. Currently, the approach that comes closest to addressing the root cause is allergen-specific immunotherapy, which is commonly known as desensitization therapy.
This method involves repeatedly exposing the patient to the vaccine, tiny amounts of pollen extracts, allowing the body to gradually adapt and eventually achieve a state of "peaceful coexistence" with the allergen.
However, desensitization therapy requires continuous year-round treatment for three consecutive years.
For those patients with severe symptoms that are not well controlled by conventional medications, biologic agents have brought new hope. These drugs target key steps in the allergic response and only require treatment during the pollen season, making them easier for patients to adhere to, said Li.
Li acknowledged that hay fever is not that frightening. It is a chronic condition, just like hypertension or diabetes, that requires long-term management. "We should neither panic excessively nor take it lightly," she said.
The allergist realized that there has been growing public attention to pollen allergies across society in recent years. For example, Beijing has taken measures such as pruning the male cone branches of sabina chinensis in advance during autumn and winter, and spraying tree canopies with pollen fixatives.
Meanwhile, cities in southern China have also begun comprehensive management of pollen and catkins.
"Spring is supposed to be a beautiful season," said Li. "When I see my patients step out of anxiety, and when I catch a whiff of floral scent by the window without sneezing, I believe that we are gradually gaining the upper hand in this battle against pollen." ■
