Conjunctivitis is swelling (inflammation) or infection of the conjunctiva. This is the membrane that lines the eyelids and covers the white part of the eye.
The conjunctiva is exposed to bacteria and other irritants. Tears help protect the conjunctiva by washing away bacteria. Tears also contain proteins and antibodies that kill bacteria.
Conjunctivitis is most often caused by a virus. Viral conjuctivitis is referred to as "pink eye." Certain forms of pink eye can spread easily among children.
Other causes include:
- Allergies (allergic conjunctivitis)
- Certain diseases
- Chemical exposure
- Parasites (rarely)
- Use of contact lenses (especially extended-wear lenses)
Newborns can be infected by bacteria in the birth canal. This condition is called ophthalmia neonatorum. It must be treated at once to preserve eyesight.
Exams and Tests
Your health care provider will:
- Examine your eyes
- Swab the conjunctiva to get a sample for analysis
Treatment of conjunctivitis depends on the cause.
Allergic conjunctivitis may improve when allergies are treated. It may go away on its own when you avoid your allergy triggers. Cool compresses may help soothe allergic conjunctivitis.
Antibiotic medicines most often in the form of eye drops work well to treat bacterial conjunctivitis. Viral conjunctivitis will go away on its own. Mild steroid eye drops may help ease discomfort. Many doctors give mild antibiotic eye drops for pink eye to prevent bacterial conjunctivitis.
You can soothe the discomfort of viral or bacterial conjunctivitis by applying warm compresses (clean cloths soaked in warm water) to your closed eyes.
The outcome is most often good with treatment.
The infection can come back if you do not take steps to prevent it from spreading.
When to Contact a Medical Professional
Call with your health care provider if your symptoms last longer than 3 or 4 days or if your vision is affected.
Good hygiene can help prevent the spread of conjunctivitis. Things you can do include:
- Change pillowcases often.
- Do not share eye makeup and replace it regularly.
- Do not share towels or handkerchiefs.
- Handle and clean contact lenses properly.
- Keep hands away from the eye.
- Wash your hands often.
Inflammation - conjunctiva; Pink eye
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Bhatt U, Lagnado R, Dua HS. Follicular conjunctivitis. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins;2013:vol 4, chap 7.
Rubenstein JB, Tannan A.. Conjunctivitis: Infectious and noninfectious. In: Yanoff M, Duker JS, eds. Ophthalmology. 4th ed. St. Louis, MO: Elsevier Mosby; 2013:chap 4.6.
Wright JL, Wightman JM. Red and painful eye. In Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Mosby; 2013:chap 22.
Yanoff M, Cameron D. Diseases of the visual system. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 431.
Update Date 9/2/2014
Updated by: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.