Acute conjunctivitis in children, also known as “pink eye,” is a contagious eye disease caused by bacterial or viral infections, and the season for this disease is high with the onset of autumn and winter. Children’s resistance is weak, and they are prone to colds and coughs in the fall and winter, which allows bacteria and viruses to take advantage of the situation. Once infected, the disease can develop within a few hours. Acute conjunctivitis in children is characterized by significant conjunctival congestion and a large amount of mucopurulent discharge. In the early stages of the disease, the child may have a foreign body sensation and photophobia, followed by redness and swelling of the eyes and face, conjunctival congestion, bright red color, and large amounts of mucopurulent secretions, and when waking up in the morning, the eyelashes of the upper and lower lids are often stuck together by the secretions, making it difficult to open the eyes. In severe cases, children may also have systemic symptoms such as fever and fatigue. Sometimes, due to the large amount of mucopurulent secretions adhering to the surface of the cornea, temporary blurring of vision may occur, which will disappear immediately after wiping it away. How can we analyze what kind of infection a child has from the symptoms? First of all, according to the nature of the conjunctival secretions, they can be classified as: aqueous secretions, mucous secretions, and purulent secretions. The secretions mainly come from the lacrimal gland, the paracrine gland, the cupped cells, and are mixed with exuded inflammatory cells, pathogenic microorganisms and necrotic tissue. In general, aqueous secretions are seen in viral conjunctivitis, mucous secretions are seen in allergic conjunctivitis, spring cicatricial conjunctivitis or conjunctivitis with impaired tear production, and purulent secretions are often characteristic of acute bacterial conjunctivitis. Next, look for subconjunctival hemorrhage, which is the rupture of small vessels in the subconjunctiva resulting in blood entering the subconjunctival tissue space as subconjunctival hemorrhage, which can be punctate or lamellar, usually bright red, or dark red when there is a lot of bleeding, and the local conjunctiva can be elevated, and small vessel bleeding close to the corneal limbus can form a limited subconjunctival hematoma. Subconjunctival hemorrhage is most often seen in epidemic hemorrhagic conjunctivitis and severe adenoviral conjunctivitis. So to briefly summarize: if a child has red eyes with more purulent discharge and no conjunctival hemorrhage, it is most likely a bacterial infection; if a child has red eyes with watery discharge and subconjunctival hemorrhagic plaques, it is mostly a viral infection. How to treat acute conjunctivitis in children? If it is a bacterial infection, it is usually treated with antibiotic eye drops or eye ointment, such as: tobramycin eye drops, tobramycin eye ointment, etc. Symptoms usually disappear within 1-2 weeks after the medication is administered. Severe bacterial infections such as keratitis have to be treated with oral antibiotics for a short period of 3-5 days along with vitreous acid sodium drops to repair the corneal epithelium. If the infection is viral, it can be treated with ganciclovir ophthalmic ointment along with oral antiviral oral solution. Most viral infections cause keratitis, so early use of sodium glacial drops is necessary. The child’s towels, pillows, and toys should be disinfected and sterilized, and the child should wash his hands regularly and not rub his eyes. Although acute conjunctivitis in children is a common eye disease, it should not be ignored. Because it is contagious, treatment should be aggressive and thorough. Once the disease is present, it should be treated immediately and without interruption, and treatment should be consolidated for about 1 week after the symptoms have completely disappeared to prevent recurrence.