Conjunctivitis or pink eye

Inflammation - conjunctiva; Pink eye; Chemical conjunctivitis, Pinkeye; Pink-eye

The conjunctiva is a clear layer of tissue lining the eyelids and covering the white of the eye. Conjunctivitis occurs when the  conjunctiva becomes swollen or inflamed.

This swelling can be due to an infection, an irritant, dry eyes, or an allergy.


Tears most often protect the eyes by washing away the germs and irritants. Tears contain proteins and antibodies that kill germs.

Pink eye is most often caused by viruses and bacteria.

  • Certain forms of pink eye can spread easily among children.
  • Newborns can be infected by bacteria in the birth canal. It must be treated at once to preserve eyesight.

Allergic conjunctivitis occurs when the conjunctiva becomes inflamed due to a reaction to pollen, dander, mold, or other allergy-causing substances.

Anything which irritates the eye may cause pink eye also. These include:

  • Chemical exposure.
  • Smoke.
  • Use of contact lenses (often with extended-wear lenses).
  • Dry eyes, which can develop when the eye is unable to maintain a healthy coating of tears. Dry eyes may be caused by wind or sun, heat, problems with your eyelids, or certain rare immune disorders.


Symptoms include:

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 work well to treat pinkeye caused by bacteria. These are most often given in the form of eye drops. Viral pink eye will go away on its own without antibiotics. Mild steroid eye drops may help ease discomfort.

Dry eyes may be treated with artificial tears or ointments. There are other treatments or helpful steps you can take.

You can soothe your eyes by applying warm compresses. Press clean cloths soaked in warm water to your closed eyes.

Other helpful steps include:

  • DO NOT smoke and avoid secondhand smoke, direct wind, and air conditioning.
  • Use a humidifier, such as in the winter.
  • Limit medicines that may dry you out and worsen your symptoms.
  • Clean eyelashes regularly and apply warm compresses.

Outlook (Prognosis)

The outcome is most often good with treatment of infections. It can come back if you do not take steps to prevent it from spreading. Pinkeye caused by viruses or bacteria can spread through contact. These have been known to spread through entire households or classrooms.

Long-term (chronic) swelling of the outer lining of the eyes may occur in those with chronic allergies or asthma. It is called vernal conjunctivitis. It is most common in young males, and most often occurs during the spring and summer.

When to Contact a Medical Professional

Contact your provider if:

  • Your symptoms last longer than 3 or 4 days.
  • Your vision is affected.
  • You develop eye pain that is severe or becoming worse.
  • Your eyelids or the skin around your eyes becomes swollen or red.
  • You have a headache in addition to your other symptom.


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.


Alvarenga LS, Ginsberg B, Mannis MJ. Bacterial conjunctivitis. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins;2013:vol 4, chap 5.

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.

Centers for Disease Control and Prevention. Conjunctivitis (pink eye): prevention. Updated June 30, 2016. Accessed September 9, 2016.

Rubenstein JB, Tannan A. Conjunctivitis: infectious and noninfectious. In: Yanoff M, Duker JS, eds. Ophthalmology. 4th ed. Philadelphia, PA: Elsevier Saunders; 2014: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 Saunders; 2014:chap 22.


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Review Date: 8/20/2016

Reviewed 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.

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