Allergic reactions are mediated by specific antibodies called IgE, which are mainly produced by B cells in the nasopharynx, tonsils, trachea and submucosa of the gastrointestinal tract, and can trigger local or systemic allergic reactions in patients when allergens invade these areas. Our eyes, nose, throat and bronchial tubes can be considered “neighbors” and often attack together if they develop. Clinically, many patients with allergic conjunctivitis often have itchy nose, sneezing and bronchial asthma. Patients have a history of allergic rhinitis or asthma, or are allergic themselves. Some patients even develop rash patches of varying sizes when their skin is touched. Episodes of allergic conjunctivitis tend to have a distinct seasonality. Many patients often have attacks at the turn of the seasons. In general, the incidence is higher in the spring and summer than in the fall and winter. Pollen, dust mites, seafood, and temperature differences are all important triggers. Some patients have an extremely clear history of allergen exposure and remission is achieved after removal from exposure to the allergen. Patients with allergic conjunctivitis often have congestion in the conjunctiva of both eyes, but this eye redness is different from the bright red congestion of “pink eye”, which appears as a dirty dark red color. The key words for “pink eye” are: sudden onset, cold fatigue, discharge or tears. There are many causes of pink eye, with bacterial, viral and Chlamydia trachomatis infections being the three most common types. Patients with bacterial conjunctivitis usually begin to develop within 1 to 2 days of infection with bacteria, and most develop in both eyes. Patients experience itchy, foreign body-like sensations in the affected eye and, in severe cases, heavy eyelids, photophobia and a burning sensation. Due to the inflammation of the conjunctiva, a large amount of mucopurulent yellowish-white discharge is produced, and the patient may wake up in the morning with the upper and lower lids stuck together with the discharge. If you have a recent history of colds, sore throat or excessive fatigue, red itchy eyes with little discharge, but heavy photophobia and tearing, significant eyelid edema, and swollen and painful preauricular lymph nodes, your doctor may have a high suspicion of viral conjunctivitis. In addition to red eyes caused by bacterial and viral infections, patients with the acute stage of trachoma can also have red, itchy eyes. Although 80-90% of people are infected with Chlamydia trachomatis, the incidence of severe trachoma has been decreasing with the economic development of people and the improvement of health care. Hormones are a dangerous elixir When a patient with allergic conjunctivitis has particularly itchy eyes or a patient with “pinkeye” has very marked conjunctival congestion and eyelid edema, hormonal eye drops may be administered at the doctor’s discretion. Hormones work very quickly, and many patients experience significant relief from discomfort within a short time of use. Some patients treat hormone drops as a “panacea” for ocular surface diseases and use them on their own whenever they have eye discomfort, even for a long time. Hormones are dangerous elixirs, and hormonal eye drops must be used under the guidance of a doctor. If used in excess, they can lead to a decrease in eye resistance and increase the risk of infection, and even cause an increase in eye pressure, glaucoma, optic nerve atrophy, etc.