Health Encyclopedia

Conjunctivitis

Definition

Conjunctivitis is an inflammation or infection of the membrane lining the eyelids (conjunctiva).

Alternative Names

Inflammation - conjunctiva; Pink eye

Causes, incidence, and risk factors

The conjunctiva is exposed to bacteria and other irritants. Tears help protect the conjunctiva by washing away bacteria. Tears also contain enzymes and antibodies that kill bacteria.

There are many causes of conjunctivitis. Viruses are the most common cause. Other causes include bacteria, Chlamydia, fungi, and rarely, parasites.

"Pink eye" refers to a viral infection of the conjunctiva. These infections are especially contagious among children.

Bacteria are an uncommon cause of conjunctivitis. Conjunctivitis is also caused by allergies (allergic conjunctivitis), chemical exposure, and certain systemic (throughout the body) diseases.

Newborns can be infected by bacteria in the birth canal. This condition is called ophthalmia neonatorum, and it must be treated immediately to preserve eyesight. Use of contact lenses, particularly extended-wear lenses, can cause conjunctivitis.

Symptoms

Blurred vision
Crusts that form on the eyelid overnight
Eye pain
Gritty feeling in the eyes
Increased tearing
Itching of the eye
Redness in the eyes
Sensitivity to light

Signs and tests

Examination of the eyes
Swab of conjunctiva for analysis

Treatment

Treatment of conjunctivitis depends on the cause.

Allergic conjunctivitis may respond to treatment for the underlying allergies, or it may disappear on its own when the allergen that caused it is removed. Cool compresses may be soothing for allergic conjunctivitis.

Antibiotic medication, usually eye drops, is effective for bacterial conjunctivitis. Viral conjunctivitis will disappear on its own. Many doctors give a mild antibiotic eyedrop for pink eye to prevent bacterial conjunctivitis.

You can soothe the discomfort of viral or bacterial conjunctivitis by applying warm compresses (a clean cloth soaked in warm water) to your closed eyes.

Expectations (prognosis)

The outcome is usually good with treatment.

Complications

Reinfection within a household or school may occur if you don't follow preventive measures.

Calling your health care provider

Call for an appointment with your health care provider if your symptoms last longer than 3 or 4 days.

Prevention

Good hygiene can help prevent the spread of conjunctivitis:

Change pillowcases frequently
Do not share eye cosmetics
Do not share towels or handkerchiefs
Handle and clean contact lenses properly
Keep hands away from the eye
Replace eye cosmetics regularly
Wash your hands often

Review Date:11/13/2007
Reviewed By:Manju Subramanian, M.D., Assistant Professor in Ophthalmology, Vitreoretinal Disease and Surgery, Boston University Eye Associates, Boston, MA. Review provided by VeriMed Healthcare Network.

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