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What is conjunctivitis?

Conjunctivitis, also known as pink eye, is an inflammation of the conjunctiva of the eye. The conjunctiva is the membrane that lines the inside of the eye and also a thin membrane that covers the actual eye.


The most common symptoms are:

  • Gritty feeling in one or both eyes
  • Itchy, irritated eyes
  • Clear, thin drainage (usually seen with viral or allergic causes); increased tearing
  • Sneezing and runny nose (usually see with allergic causes)
  • Stringy discharge from the eyes (usually seen with allergic causes)
  • Thick, green drainage from the eyes (usually seen with bacterial causes)
  • Lesion with a blister or crusty appearance (usually seen with herpes infection)
  • Eyes that are matted together in the morning
  • Swelling of the eyelids
  • Pink or red discoloration of the whites of one or both eyes
  • Discomfort when the child looks at a light
  • Burning in the eyes

The symptoms of conjunctivitis may look like other medical conditions or problems. Always consult your health care provider for a diagnosis.


There are many different causes of conjunctivitis. The following are the most common causes:

  • Bacteria
  • Viruses
  • Allergies
  • Immune system problem
  • Chemicals
    • Seen sometimes in the newborn period after the use of medicine in the eye to prevent other problems
    • Seen shortly after contact with an irritating substance, such as chlorinated water in swimming pools, chemical vapors, fumes, ammonia and air pollution

How is it diagnosed?

Conjunctivitis is usually diagnosed based on a complete medical history and physical exam of your eye. Cultures of the eye drainage are usually not required, but may be done to help confirm the cause of the infection.


Conjunctivitis is usually divided into at least two categories—newborn conjunctivitis and childhood conjunctivitis—with different causes and treatments for each.

Newborn conjunctivitis

The following are the most common causes and treatment options for newborn conjunctivitis:

  • Chemical conjunctivitis—This is related to an irritation in the eye from the use of eye drops that are given to the newborn to help prevent a bacterial infection. Sometimes, the newborn reacts to the drops and may develop a chemical conjunctivitis. The eyes are usually mildly red and inflamed, starting a few hours after the drops have been placed in the eye, and lasts for only 24 to 36 hours. This type of conjunctivitis usually requires no treatment.
  • Gonococcal conjunctivitis—This is caused by a bacteria called Neisseria gonorrhea. The newborn obtains this type of conjunctivitis by the passage through the birth canal from an infected mother. This type of conjunctivitis may be prevented with the use of eye drops in newborns at birth. The newborn eyes usually are very red, with thick drainage and swelling of the eyelids. This type usually starts about two to four days after birth. Treatment for gonococcal conjunctivitis usually will include antibiotics through an intravenous (IV) catheter.
  • Inclusion conjunctivitis—This is caused by an infection with chlamydia trachomatis, obtained by passage through the birth canal from an infected mother. The symptoms include moderate thick drainage from the eyes, redness of the eyes, swelling of the conjunctiva, and some swelling of the eyelids. This type of conjunctivitis usually starts five to 12 days after birth. Treatment usually will include oral antibiotics.
  • Other bacterial causes—After the first week of life, other bacteria may be the cause of conjunctivitis in the newborn. The eyes may be red and swollen with some drainage. Treatment depends on the type of bacteria that has caused the infection. Treatment usually will include antibiotic drops or ointments to the eye, warm compresses to the eye and proper hygiene when touching the infected eyes.

Childhood conjunctivitis

Childhood conjunctivitis is a swelling of the conjunctiva and may also include an infection. It is a very common problem in children. Also, large outbreaks of conjunctivitis are often seen in daycare settings or schools. The following are the most common causes of childhood conjunctivitis:

  • Bacteria
  • Viruses
  • Allergies
  • Herpes

Types of treatment

Your child's health care provider will consider your child's age, overall health, medical history and other factors when advising treatment. Specific treatment depends on the underlying cause of the conjunctivitis.

  • For bacterial causes—The doctor may order antibiotic drops to put in the eyes.
  • For viral causes—Viral conjunctivitis usually does not require treatment. However, it may be difficult to know whether the cause is viral or bacterial, so the health care provider may prescribe drops to cover a bacterial infection as well.
  • For allergic causes—Treatment for conjunctivitis caused by allergies usually will involve treating the allergies. The doctor may order oral medications or eye drops to help with the allergies.
  • For herpes—If your child has an infection of the eye caused by a herpes infection, the doctor may refer you to an eye care specialist. Your child may be given both oral medications and eye drops. This is a more serious type of infection and may result in scarring of the eye and loss of vision.
  • For chemical (irritant) in children—Treatment for conjunctivitis caused by mild chemical exposure usually will involve flushing of the eyes with saline. The doctor may order steroid eye drops. Exposure of harsh chemical, such as alkali and acids, to the eyes are medical emergencies and can lead to serious injuries. Call 911 immediately.

Other instructions

Infection can be spread from one eye to the other, or to other people, by touching the affected eye or drainage from the eye. Proper hand washing is very important. Also avoid touching your eyes with your hands, change pillowcases frequently and do not reuse tissues or hand towels on your face. Drainage from the eye is contagious for 24 to 48 hours after beginning treatment. 

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