Pollen brings spring troubles. Experts teach you protective tricks.

　　Plant pollen can be divided into wind-borne pollen and insect-borne pollen. The pollen of brightly-blooming flowers pollinated by insects is insect-borne flower powder, and this kind of pollen is generally not allergic. What makes people allergic is wind-borne flower powder, which can drift away for several kilometers or even more than ten kilometers with the wind.

　　— — Cheng Lei, Director of Otolaryngology Department of jiangsu province hospital, Chairman-designate of Allergy Branch of Chinese Medical Association.

　　◎ Science and Technology Daily reporter Jin Feng

　　In today’s beautiful spring when everything is recovering, there are always faces that frequently raise cameras and mobile phones among the flowers and trees. However, not everyone can accept the generous gift of nature with peace of mind.

　　For some special friends, not to mention entering the flowers to enjoy the flowers, as long as they enter the pollen "range", they will turn red, and erythema and papules on their skin will "come one after another"; Or rhinitis and asthma induced by pollen, with symptoms such as sneezing, coughing, runny nose and tears.

　　Recently, the "National Early Warning Map of Pollen Allergy" made by China Weather Network became popular. This map, based on the data of China Meteorological Bureau at 8: 00 on March 25th, shows that most of the central and eastern parts of China are in areas that are easy to induce pollen allergy, and the allergy index of Shanxi, Shaanxi, Henan, Jiangsu, Hubei and other provinces continues to rise. However, the pollen allergy index in most areas of Hunan and Jiangxi affected by rainfall decreased significantly. Pollen-free areas are mainly concentrated in the three northeastern provinces, Inner Mongolia and Tibet.

　　So, why is pollen allergic? How can we prevent and relieve allergic symptoms? In response to the above problems, the Science and Technology Daily reporter interviewed a number of experts to reveal the secrets for you.

　　Not all allergies are caused by flowers.

　　Jiangsu, which is in the early warning area in the "National Pollen Allergy Early Warning Map", has recently seen an increase in the number of allergic people.

　　"I was on duty on March 27, and there were 8 patients with facial allergies, basically women." On March 29th, when interviewed by the reporter of Science and Technology Daily, Zhou Lin, the attending physician of dermatology in Jiangsu Hospital of Integrated Traditional Chinese and Western Medicine, was as busy as a bee in the outpatient clinic. "Every year, the number of patients with facial allergies will increase significantly in this season and in August and September."

　　Data show that pollen is the male cell of plants in nature, and its size, shape and structure vary widely due to different species, and most of them are measured in microns. In the spring when the grass grows and the warbler flies, the plants bloom and leave loose, and the pollen is scattered into the air with the help of breeze, butterflies and bees, so that the plants can thrive.

　　When it comes to pollen allergy, many people think that "this is all caused by flowers", but it is not.

　　"There are three main types of pollen allergy: one is tree pollen in spring, the other is gramineous pollen in spring and summer, and the other is weed pollen in autumn." Cheng Lei, director of the Department of Otolaryngology, jiangsu province hospital and chairman-designate of the Allergy Branch of the Chinese Medical Association, told the Science and Technology Daily reporter that plant pollen can be divided into wind-borne pollen and insect-borne pollen. The pollen of brightly-blooming flowers pollinated by insects is insect-borne flower powder, and this kind of pollen is generally not allergic. What makes people allergic is wind-borne flower powder, which can drift away for several kilometers or even more than ten kilometers with the wind.

　　Relevant experts said that the wind-borne flower powder is small, too small to be seen by the naked eye, very light and large in quantity. When the wind blows, pollen floats in the air in large quantities, and people are easily sensitized after contact and inhalation.

　　Pollen is a frequent visitor in the air. "In spring, tree pollen generally begins to drift from March to April, and then gramineous pollen comes on stage. In autumn, weed pollen generally appears in August and September, and pollen still drifts in some areas even in November." Cheng Lei said.

　　These pollen with different "identities" have different sources.

　　According to Cheng Lei, as far as tree pollen in spring is concerned, the sensitized pollen in the northern region mainly comes from poplar, willow, birch and hazel, while the sensitized pollen in the southern region mostly comes from poplar, willow, cypress and pine. As for Nanjing and even East China, the main allergenic pollen comes from Platanus acerifolia, which generally drifts from mid-April until early May. Gramineae pollen in spring and summer mainly comes from grass such as duck grass.

　　"The pollen of the most common allergic weeds in autumn in China mainly comes from wormwood, ragweed and humulus scandens, among which wormwood is more common in the northern region north of the Yellow River and also in the southern region, but it is relatively rare." Cheng Lei said.

　　Environmental factors aggravate pollen allergy symptoms.

　　Looking closely at the "National Pollen Allergy Warning Map", the pollen allergy index in different regions is not the same. The reasons for the different allergic indexes in different places are not only the different distribution of plants from which sensitized pollen comes, but also the differences in climate and temperature.

　　Cheng Lei said that the flowering time of plants is closely related to the temperature. "For example, in a certain year, the temperature warms up late, and the average temperature is more than 1 degree Celsius lower than that in the same period of last year. At this time, the time when pollen begins to drift will be late, which will be delayed by 5 to 8 days or even 10 days. However, if the temperature difference is within 0.5 degrees Celsius, the impact will be small. " Cheng Lei said.

　　"In addition, some studies have shown that air pollution will aggravate the symptoms of pollen allergy." Cheng Lei said that in recent years, due to air pollution in some areas, the incidence of seasonal pollen allergy and perennial respiratory allergic diseases have shown an obvious upward trend, and some people even superimpose the two diseases.

　　"Overall, the incidence of respiratory allergic diseases has increased by more than 100% in the past 20 years, such as allergic rhinitis and asthma. Changes in the environment and the interaction between the environment and genes have led to an increase in the number of people suffering from such diseases. " Cheng Lei said that in addition, the increase in work and life pressure will also lead to an increase in the number of people suffering from allergic diseases.

　　"If the pollen drifts for a long time, some patients’ respiratory allergic symptoms may last for 1 to 3 months, especially in the two or three weeks when the pollen concentration is high, and the symptoms will be very serious." Cheng Lei said.

　　These susceptible people with allergies will be even more miserable if they encounter the help of "God" again. "If you encounter a sunny windy day, the pollen will drift faster and the number of allergic people will be more. The allergic reaction is manifested in the face, that is, erythema and papules, and the skin has an itchy feeling. " Zhou Lin said.

　　Wearing masks and goggles can prevent

　　In the face of this slightly challenging gift from nature, allergic people don’t have to be afraid of everything, but they should also take precautions.

　　Cheng Lei suggested that we should pay attention to the monitoring and forecasting information of pollen spread as much as the weather forecast. When pollen spreads, we should wear a good mask when going out, preferably N95 or KN95 mask, to block some pollen with smaller particles.

　　"Conjunctivitis patients should also wear goggles. Ordinary glasses are not good, and the glasses need to be sealed around." Cheng Lei said.

　　Zhou Lin suggested that allergic people should wear hats and long-sleeved coats when they go out, wash their clothes in time when they get home, try not to dry them outdoors, and keep doors and windows open as little as possible. "You can also try to use a pollen barrier and apply it to the nasal cavity before going out, which can form a protective film in the nasal mucosa to prevent pollen from contacting the mast cells of the human body and induce allergies. Patients with facial allergies can also wet the face with normal saline for 15 minutes each time, once in the morning and evening. " Zhou Lin said.

　　Zhou Lin suggested that people should eat more vitamin C and take more exercise to enhance their resistance. "In the outpatient clinic, we found that proper exercise can reduce the recurrence probability of allergic symptoms." She said.

　　"Prevention first, prevention first." Cheng Lei said that patients with pollen allergy can also start taking related drugs or using nasal spray hormones two to three weeks before onset according to their onset time in previous years. For example, many patients in Nanjing will have nose and eye symptoms around April 20, so during the period from early April to early April, people with allergies in need will start preventive treatment to relieve symptoms or suppress symptoms.