The best way to fight pink eye is with hygiene

Itchy eyes from allergies or infection

Dear Doctors: Our 7-year-old came home from school with an itchy eye. A few days later, all three of our kids, plus my husband and I, had pink eye. Our family doctor gave us antibiotic eyedrops, and it was gone in a few days. What causes pink eye? What can you do to keep it from spreading?

Dear Reader: Pink eye is the common name for an infection known as conjunctivitis. It’s the most frequent cause of eye inflammation and occurs in an area of the eye known as the conjunctiva. That’s a thin, clear membrane that covers the white of the eye and lines the inner eyelid. The conjunctiva protects the eye from potential irritants and pathogens. It is nourished by a dense network of minute blood vessels, and it is the site of numerous lymphatic vessels, which are involved in immune response. The conjunctiva also plays a role in producing tears and mucus, which keep the exposed surfaces of the eye moist and lubricated.

Viral infection accounts for about 80% of cases of conjunctivitis. The cause is usually an adenovirus. Bacterial conjunctivitis is seen more often in children than in adults. While not as common, fungi and parasites can also cause infectious conjunctivitis.

Once the infection is present, it can spread easily and quickly. If someone touches the contaminated fluid or discharge from an infected person’s eye and then touches their own eye, they can transfer the bacterium or virus. As with a cold or the flu, the microbes can also be spread via respiratory droplets.

Conjunctivitis can also be caused by noninfectious agents, such as irritants to the eye, as well as allergies. In those instances, the condition is not contagious.

Pink eye gets its name from its most prominent symptom. When someone develops this type of infection, that network of tiny blood vessels that we mentioned becomes inflamed. This causes the whites of the eye to turn pink, or even red. The inner eyelid often becomes swollen, the membranes of the eyes begin to itch or burn, and the eyes may begin to tear. When the cause of conjunctivitis is bacterial, a discharge is often present.

Elizabeth Ko, MD and Eve Glazier, MD

Treatment for all types of conjunctivitis begins with managing the symptoms. This includes using a warm compress every few hours to keep the eyelid and lashes clean and moist and artificial tears to ease itching and dryness. People who wear contact lenses should pause their use until the infection has cleared. When the source of the infection is bacterial, as occurred in your family, antibacterial eyedrops may be prescribed. But antibiotics don’t affect viruses. In viral cases of conjunctivitis, the infection must run its course. Conjunctivitis typically clears up in seven to 14 days.

Prevention hinges on hygiene. Wash hands before and after touching your eye. Change pillowcases daily while infection is active. Don’t share personal items, such as washcloths, medications, makeup or eyeglasses. Be sure to throw away eye drops, solutions or eye makeup that were used while the family was infected. If symptoms persist -- or if they are accompanied by pain, sensitivity to light or blurred vision -- it is important to see a doctor.

(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)