I. What are the common allergic diseases of the eye? The eye surface is directly exposed to the external environment and can come into direct contact with allergic substances, making it prone to various allergic diseases. There are five main types of common allergic diseases of the eye: 1. Allergic conjunctivitis: the most common, accounting for about 50% of allergic diseases of the eye. 2, spring catarrhal conjunctivitis: mostly seen in adolescents, often occurring or aggravated in spring and summer, with a male to female ratio of 2:1, with a higher incidence in hot flush areas, and severe patients can affect vision. 3, giant papillary conjunctivitis: with the wearing of corneal contact lenses, prosthetic eyes, exposed sutures, 15% of patients wearing soft corneal contact lenses can occur giant papillary conjunctivitis. 4, atopic keratoconjunctivitis: is a kind of keratoconjunctivitis associated with atopic dermatitis, congenital allergy is the main factor, the peak age of onset is mostly in 30-50 years old. 5. Contact allergic conjunctivitis: Patients often have a clear history of exposure, such as a history of exposure to drugs, cosmetics or hair dyes, and symptoms are relieved after avoiding exposure. Second, what causes eye allergy? Allergic reactions can occur when the conjunctiva on the surface of the eye comes into contact with particles of an allergenic substance suspended in the air, which are medically known as “allergens”. When these allergens enter the eye, they bind to the mast cells of the conjunctiva, resulting in the release of histamine from the mast cells and producing symptoms of redness, swelling and itching. If the allergen is removed in time, the symptoms can be relieved or even disappear. If the exposure continues, other cells in the conjunctiva also participate in the allergic reaction, causing the patient’s symptoms to persist or worsen. What are the common allergens of allergic conjunctivitis? Allergic conjunctivitis is the most common ocular allergic disease, divided into 2 types according to performance: 1. Seasonal allergic conjunctivitis: the most common, seasonal onset, mainly related to outdoor airborne pollen, grass pollen, mold, etc., mostly seen in spring and summer; 2. Perennial allergic conjunctivitis: perennial onset, can be seasonally aggravated, mainly related to dust mites, mold, animal dander, cosmetics, cotton and linen products, etc. Indoor perennial allergy far related. Fourth, how to find and find allergens? Individuals vary greatly, and allergens vary from person to person, so you can go to the hospital to find allergens further. What are the manifestations of allergic conjunctivitis? The typical manifestations of seasonal allergic conjunctivitis are sudden onset of unbearable eye itching, tearing, redness and swelling, and in severe cases, burning sensation and conjunctival edema. The symptoms disappear within a few hours after removal from the allergen, but reappear immediately if the allergen is re-exposed. These symptoms come and go during the allergy season and recur, depending on the climate and the patient’s activities. Some patients also have allergic rhinitis and asthma in addition to eye discomfort. Patients with perennial allergic conjunctivitis may also experience these symptoms, but they are less severe than seasonal allergic conjunctivitis. Does allergic conjunctivitis affect my eyesight? Allergic conjunctivitis usually has no effect on vision, but in order to relieve the itchy symptoms, some patients (especially children) rub their eyes, which may cause damage to the corneal epithelium and affect their vision. In some patients with severe spring catarrhal keratoconjunctivitis, the giant papillae formed on the conjunctiva have a damaging effect on the corneal epithelium, even causing corneal ulcers that can seriously affect vision. 7. How to treat allergic conjunctivitis? The most important thing in treatment is to be able to identify and immediately avoid contact with the allergen, and the symptoms can be relieved quickly even without medication. If the allergen cannot be identified or removed immediately, further medication is required. The main purpose of medication is to relieve symptoms. If the symptoms are mild, topical artificial tears can be used to flush and dilute the allergen, but if they are not relieved, further medication under medical supervision is required. Medication mainly includes mast cell stabilizers, the main role is to stabilize the cell membrane of mast cells and reduce the release of histamine and other factors that cause allergy, these drugs are slow to work, but have the effect of relieving symptoms and preventing allergies; secondly, H1 receptor blockers, mainly to reduce histamine caused by allergic reactions, has a significant anti-itch effect; after treatment if the symptoms are not relieved, you can use glucocorticoid eye drops for a short period of time. If the symptoms are not relieved, glucocorticoid eye drops can be used for a short time. Why does allergic conjunctivitis persist? Allergic conjunctivitis is caused by contact with one or more allergens in the conjunctival tissues of the eye, and the symptoms are relieved or disappear when the allergens are removed. However, most patients are not able to identify the exact allergen, or have identified the allergen and are unable to avoid contact in their lives, thus making allergic conjunctivitis recurrent and not easily cured. In addition, the main purpose of the current drug treatment is to relieve symptoms, after stopping the drug if you continue to contact allergens can still relapse, resulting in allergic conjunctivitis is not cured. How to prevent allergic conjunctivitis? First of all, to improve the living environment, thorough cleaning of indoor hygiene, reduce dust, pay attention to indoor ventilation, diligent change of bed sheets, pillowcases, do not keep pets, so that the impact of allergens to reduce. For those who are allergic to outdoor antigens such as pollen, try to reduce outdoor activities or use goggles during pollen-rich seasons. Secondly, exercise, strengthen the body, regular life and rest, and pay attention to a healthy and appropriate diet, all of which can increase the body’s potential to fight allergy attacks and reduce and slow them down. For patients with allergic conjunctivitis, especially seasonal allergic conjunctivitis, some mast cell stabilizer eye drops, such as sodium cromoglycate, can be used before the onset of spring and summer, which can play a preventive role.