Allergic conjunctivitis, also known as allergic conjunctivitis, is a hypersensitivity reaction of the conjunctiva to external allergens. It mainly includes type I allergic reaction and type IV allergic reaction, among which allergic conjunctivitis due to type I allergic reaction is the most common. Specific treatment methods are as follows: 1. General treatment Removal of allergens is the most ideal and effective treatment. Contact with possible allergens should be avoided as much as possible. For example, remove rags and blankets from the room, pay attention to bed hygiene, use insecticides to eliminate insect mites in the room, avoid contact with grass and tree flowers during the pollen spreading season, and stop wearing or replace quality contact lenses and care solutions. Cold compresses on eyelids can temporarily relieve symptoms. 2. Medication (1) Antihistamines: Antihistamines are usually used topically, and commonly used eye drops include 0.1% Emedastine, 0.05% Levocabastine, 0.1%? If extraocular symptoms are present, they can be used orally, although they are not as effective as topical medications. Commonly used oral medications include Benadryl, Chlorpheniramine, and Promethazine. The combination of antihistamines and vasoconstrictors can often achieve better therapeutic results such as Ruminative. (2) Mast cell stabilizers: commonly used disodium colored glycolate and nedolomide, etc. The overall therapeutic effect of mast cell stabilizers is not as good as antihistamines, but they seem to be more effective in suppressing lacrimation. They are best used before exposure to allergens. (3) Non-steroidal anti-inflammatory drugs: They can be used in both the acute and intermittent phases of allergic attacks, and have shown some therapeutic effect on relieving eye itching, conjunctival congestion, lacrimation and other ocular signs and symptoms, and it can also reduce the dose of hormones, commonly used are indomethacin (diclofenac sodium), aspirin, etc. (4) vasoconstrictors: commonly used drugs for local use include epinephrine naphthazoline, hydroxymetazoline, tetrahydrozoline, etc., which can improve eye discomfort and reduce ocular surface congestion. (5) Glucocorticoids: Severe allergic conjunctivitis should only be considered when other medications are ineffective and should not be used for too long to avoid complications such as cataract, glaucoma monocytic virus infection, fungal infection and delayed corneal epithelial healing. Commonly used are dexamethasone, betamethasone and flumetron. (6) Immunosuppressants: mainly cyclosporine A and FK506 For some severe cases of springtime keratoconjunctivitis requiring hormone use, topical application of 2% cyclosporine A can quickly control local inflammation and reduce the amount of hormone use. However, it is easy to recur after stopping the drug. Desensitization therapy This method is mainly used for seasonal allergic conjunctivitis. For other subtypes of allergic conjunctivitis, the therapeutic effect is often unsatisfactory and therefore rarely used. Cryotherapy This method is mainly used for springtime keratoconjunctivitis. Cryotherapy is commonly used on the upper lid conjunctiva, where the temperature is lowered to -80°C to -30°C for 30 seconds. Cryotherapy can be repeated 2 to 3 times. 5. Psychotherapy Ocular allergic disease is an acute or chronic recurrent disease, and complete cure is often very difficult. Therefore it causes greater psychological stress to some patients. In particular, some children with springtime keratoconjunctivitis may develop certain psychological disorders that should be noted.