Conjunctivitis Health Article

Conjunctivitis

Conjunctivitis is an infection or inflammation of the conjunctivae, the thin layer of cells which covers the surface of the sclerae (whites) of the eye and also the inside of the lids.

Conjunctivitis can be caused by a number of conditions, varying with the age of a child. In the newborn period, several types of conjunctivitis can be acquired through the birth canal, most commonly gonorrheal conjunctivitis and chlamydial conjunctivitis. Gonorrheal conjunctivitis generally produces a profuse, pus-like discharge. Left untreated, it can lead to blindness. Chlamydial conjunctivitis in the newborn period produces symptoms which are much more subtle, namely a mild redness and eye discharge several days or weeks after birth. Chemical (silver nitrate) or antibiotic eye drops are routinely administered in most hospital nurseries to prevent gonorrheal and chlamydial conjunctivitis. The silver nitrate drops used to prevent gonorrheal conjunctivitis often produce a mild chemical conjunctivitis of their own, characterized by redness of the conjunctivae and swelling of the lids. This form of conjunctivitis is harmless and usually clears up on its own.

A common type of conjunctivitis in the later new-born period is associated with lacrimal duct stenosis (blocked tear duct). If the tear duct (which drains tears from the eye into the nose) is congenitally blocked or not formed, the tears will drain poorly, and that eye will be more prone to minor conjunctival infections. Most blocked tear ducts open on their own in the first year of life. If they do not, they can be opened surgically in the second half of the first year. In preschool-age children, bacterial conjunctivitis can sometimes occur with ear infections.

The causes of conjunctivitis in school-age and older children are similar to those in adults, most commonly allergies and viruses. Allergic conjunctivitis—whose primary symptoms are itchiness of the eyes, redness of the lids, and a stringy, clear discharge—can be present year-round (perennial allergic conjunctivitis) or only when spring or fall pollens are in the air (seasonal allergic conjunctivitis). Direct infection with viruses, especially a group of viruses called adenoviruses, constitutes the other major cause of conjunctivitis in older children. Sometimes these can become secondarily infected. Styes of the lid can also cause a secondary conjunctival irritation. A less common cause of conjunctivitis is herpes simplex virus, which is usually introduced to the eye after touching an active herpes lesion. In addition, severe chemical conjunctivitis can result from alkaline detergents in the eye.

The lay term for conjunctivitis, "pinkeye," is very nonspecific. A number of diseases can cause "pinkeye" that is not technically conjunctivitis. Danger signs requiring prompt medical attention are eye irritation in a contact lens wearer (especially one who wears soft contact lenses), severe swelling of the eye or eyelids, severe pain, photophobia (sensitivity to light), a foreign body sensation in the eye, persistent blurred vision, a bulging eye, a pupil that is unreactive to light, or symptoms that become worse despite several days of treatment.

—Marta M. Vielhaber, M.D.
Kaiser-Permanente, Cleveland