Dongdong, a 6-year-old boy, always rubs his eyes with his hands or blinks his eyes every spring and fall, feeling like there is something in his eyes. Sometimes he also says his eyes are itchy and swollen. The doctor often told him that it was conjunctivitis and that he could get some relief after taking eye medication. In fact, this is typical of allergic conjunctivitis, where various allergens enter the eye and bind to immunoglobulin E (IgE) on the mast cells of the conjunctiva, resulting in the release of histamine from the mast cells, which causes small local blood vessels to dilate, producing redness, swelling and itching. Allergic conjunctivitis is not very serious, but frequent itchy eyes can have a major impact on life, and some children can develop amblyopia or even multiple twitching. Children’s weaving organs are not yet mature and the conjunctival mucosa is extremely permeable, making them a natural candidate for allergic conjunctivitis. Allergic conjunctivitis is a common condition in pediatric ophthalmology and is one of the most common symptoms of allergic children and one of the earliest allergy symptoms to occur. Many children start tearing and rubbing their eyes at the age of three months. Allergic conjunctivitis includes seasonal allergic conjunctivitis, contact allergic conjunctivitis, etc. It is when certain substances such as pollen, mold, mites, dust, bacterial proteins, animal proteins, plants, and vegetables cause allergic reactions in the conjunctiva of the eyes through various routes such as contact, inhalation, ingestion, and injection. Seasonal allergic conjunctivitis: Seasonal allergic conjunctivitis is an allergic reaction produced by airborne specific allergens, mainly spring pollen and autumn pollen, which are very small particles, airborne, spread over long distances, and affect a wide range of areas, and have a distinct seasonal onset. Seasonal conjunctivitis presents with sudden redness of the eyes, itching, tearing, burning sensation, eyelid edema, conjunctival edema, and a low and watery discharge. Unlike other infectious conjunctivitis where itching and tearing are uncomfortable, infectious conjunctivitis is dominated by pain, astringency, and burning sensation. Most patients have allergic rhinitis or asthma. If the allergen is removed, or if anti-allergy medication is given, the reaction resolves within a few hours without leaving a trace. The above symptoms appear again immediately upon re-exposure to the allergen. These symptoms can come and go during the allergy season, recurring until after the pollen season, and are closely related to the climate. Due to the airborne nature of the disease, symptoms are relatively worse on warm, dry days. On rainy and humid days, the symptoms are relatively mild. This allergy rarely invades the cornea, the allergy season is relatively short and has relatively little effect on vision. The prevention and treatment of allergic conjunctivitis is relatively simple, and avoidance of allergens is the fundamental approach. However, because allergens float in the air, the particles are so small that they are practically pervasive, which makes complete avoidance a moot point. Then reduce allergens becomes the best prevention method, followed by preventive medicine. 1, reduce the number of allergens: allergy season to reduce the number of times to open the window ventilation, open the window ventilation can open the humidifier, increase the humidity of the air, you can let the air floats land, deposition. When you return from an outing, you can rinse your eyes with artificial tears or saline to reduce the allergens that have entered your eyes. 2, preventive medicine: allergens enter the eye and combine with immunoglobulins on the mast cells of the conjunctiva, resulting in the release of histamine from the mast cells, which can make small blood vessels dilate and produce redness, swelling and itching. You can prevent allergic reactions by ordering drops containing mast cell stabilizers, such as sodium cromoglycate eye drops, before the allergy season. 3. Treatment: For the mild acute stage, ice packs and artificial tears or saline to flush the eyes can reduce the symptoms. For severe symptoms, antihistamine and decongestant eye drops are needed. If the symptoms are not relieved, a hospital visit may be necessary, perhaps with steroids, which should not be used long-term and need to be used as prescribed. Perennial allergic conjunctivitis: The main allergens of perennial conjunctivitis include molds, mites, pet fur and secretions, and dust. The main manifestation is eye discomfort, easy blinking and eye rubbing. As perennial does not heal, it can have an impact on the child’s vision and can aggravate amblyopia and myopia. Some children with amblyopia and myopia can be relieved or even cured by treating allergic conjunctivitis. The main prevention method is to reduce the number of allergens, to do the following: 1, away from pets, pet fur, dander, secretions can be allergens, resulting in children’s allergies, especially cats, even if the cat removed a year later, in the home will be measured to the cat’s allergens. 2, away from plants and animals that need water, mold is associated with moisture, water is the cornerstone of mold growth, turtles and flower pots are the best carrier of mold. 3, diligently wash and change bedding, mites are human dander as food, that is, mites are inseparable from people, mainly living in bed, to reduce the impact of mites should be diligently wash and change bed sheets and bedding, preferably with hot water above 50 degrees. Contact allergic conjunctivitis: This type of conjunctivitis has little to do with the season and occurs mainly through oral injection or direct contact, including medications, cosmetics, contact lenses, and toxins from pathogenic microorganisms, and is prevented by avoiding contact or washing after contact. Prognosis: Many allergic conjunctivitis are self-limiting and should not be stressed. The main goal of treatment is to reduce symptoms and avoid sequelae. However, because allergies are long-term, pharmacologic anti-allergy treatment can only control allergy symptoms and is hardly a complete cure for allergic conjunctivitis. Individual children with combined allergic rhinitis and airway hyperreactivity often have frequent eye blinking, nose shrugging and throat clearing due to eye discomfort, nose discomfort and throat discomfort, and over time, multiple twitching can occur. For children who do not heal for a long time, you can also consider changing the environment to prevent the occurrence of allergies.