Cause
Conjunctivitis is caused by an inflammation of the conjunctiva, the thin membrane that covers the whites of the eyes and lines the inner surface of the eyelids. About 80 percent of infectious conjunctivitis cases are caused by bacteria, and the rest are caused by viruses. Allergies or exposure of the eyes to chemicals or other irritants can also be causes.
Symptoms
Symptoms include discomfort or the sensation that something is in the eye, followed by redness and inflammation of the conjunctiva. After a day or so, there may be a discharge from the eye. In bacterial conjunctivitis, the discharge is thick and pus-like; in viral conjunctivitis, the discharge usually is watery. The eyelashes may be matted and stuck together when the child wakes in the morning.
How It Spreads
It is spread through contact with discharge or secretions from the infected eye of someone else.
Incubation Period
For bacterial conjunctivitis, the incubation period is a few days; for viral, it is up to a week.
How Long Symptoms Last
Bacterial conjunctivitis lasts 7 to 10 days if untreated. Viral conjunctivitis can last as long as two weeks.
When to Call Your Child’s Doctor
If your child—particularly your newborn—has any of the symptoms of conjunctivitis, call your child’s doctor. Also, call the doctor if your child complains of severe pain, a change in vision, or sensitivity to light, or if your child’s condition does not get better in four to five days.
How the Diagnosis Is Made
The doctor will examine your child’s eye and in some cases may take a swab of the discharge for lab analysis.
Treatment
Often infectious conjunctivitis will resolve by itself, but doctors usually prescribe antibiotic drops or ointment to decrease the possibility of spreading it to others. Drops are usually prescribed for a week, about four doses a day. Ointment, usually prescribed for infants, is given two times daily and can temporarily blur vision. Children with prolonged or repeated bouts of reddened, itchy, and watery eyes may benefit from treatment for allergies or removal of irritants (such as cigarette smoke) from their environment.
Home Treatment
Warm compresses (a clean washcloth soaked in water) can help loosen crusts on eyelids and lashes. Gauze or cotton balls dipped in warm water can be used to carefully clean the infected eye.
Prevention
Your child should wash her hands after touching the infected eye. Others touching the child’s infected eye should also wash hands. Gauze or cotton balls used to clean the eye should be thrown away; child’s towels, washcloths, and pillowcases should be washed in hot water.
Contagious Periods
Children with bacterial conjunctivitis are contagious as soon as symptoms appear; the child will remain contagious as long as there is discharge or with bacterial conjunctivitis, until antibiotics have been given for 24 hours. Viral conjunctivitis is contagious before the onset of symptoms and for as long as the symptoms last. Children should not be in school or a child-care center while they have visible symptoms of conjunctivitis.
Complications
Some bacteria can cause both conjunctivitis and middle ear infection (otitis media) at the same time.