Conjunctivitis

Definition

Conjunctivitis is the inflammation of the conjunctiva (the membrane that lines the eyelids and covers the exposed surface of the eyeball).

Conjunctivitis can be caused by allergies, bacteria, viruses, chemicals, or underlying health conditions.

Description

The eyes are susceptible to infection because they are not sterile. They rely on lysozyme (an enzyme found in the tears) to destroy bacteria. Bacteria line the surface of the eyelids (all the way down into the shaft of the eyelashes), which makes the conjunctiva predisposed to germs and conjunctivitis.

Causes and Risk Factors

Conjunctivitis can be classified as infectious or noninfectious.

Infectious conjunctivitis (pinkeye) accounts for 70 percent of all cases and is caused by either a bacteria (usually staphylococci, pneumococci, streptococci or chlamydia trachomatis) or a virus.

Bacterial conjunctivitis occurs in 50 percent of all cases, and viral conjunctivitis occurs in 20 percent. Infectious conjunctivitis is very contagious.

Noninfectious conjunctivitis (which accounts for the remaining 30 percent of all cases), can be caused by allergies (such as pollen or grass), chemicals (such as air pollutants, smoke or household cleaners), or underlying diseases (such as rheumatoid arthritis, cytomegalovirus (CMV), lupus, Kawasaki's disease, ulcerative colitis or Crohn's disease.

Additionally, conjunctivitis can be caused by hemorrhaging from trauma or changes in pressure within the head (subconjunctival hemorrhage).

An incompletely opened tear duct or herpetic conditions (such as herpes simplex or herpes zoster) also can cause conjunctivitis.

Symptoms

The symptoms of infectious conjunctivitis caused by a bacteria or viruses are:

• Eye pain

• Swelling of the eyes

• Redness in the eyes

• Yellow, green or watery discharge from the eyes which collects overnight and crusts over the eye

• A gritty feeling in the eye

• Itching of the eye

• An enlarged lymph gland in front of the ear

The symptoms of conjunctivitis caused by allergies are:

• Intense itching of the eye

• Excessive tearing of the eye

• Swelling of the eye

• Redness of the eye

• Sneezing

• Runny nose

Symptoms for the other causes of noninfectious conjunctivitis are dependent on the circumstances (i.e., if the conjunctivitis is caused by smog, the person may experience itchy, red eyes; if the conjunctivitis is caused by a chemical in the eye, the person may experience burning, red eyes and blurred vision).

Treatment

A physical examination usually reveals redness and swelling of blood vessels in the conjunctiva. The doctor may take a specimen of conjunctival scrapings to determine if the conjunctivitis is bacterial, viral or caused by other sources, such as allergies or chemicals.

Treatment of conjunctivitis varies with the cause.

Infectious Conjunctivitis

For bacterial conjunctivitis, most ophthalmologists recommend the use of mild, broad-spectrum antibiotics, such as trimethoprim sulfate/polymyxin B sulfate ophthalmic solution (Polytrim), polymyxin B sulfate/zinc bacitracin ophthalmic ointment (Polysporin), or sodiumsulfacetamide 10 percent ophthalmic ointment or solution (AK-Sulf, Bleph-10, Sodium Sulamyd). Additionally, the ophthalmologist may prescribe ciprofloxacin HCL (Ciloxan) and norfloxacin (Chibroxin) for more serious ocular disorders.

Viral conjunctivitis usually disappears on its own. However, doctors may prescribe antibiotics to prevent a secondary bacterial infection.

To soothe the irritation and combat the symptoms, the doctor will prescribe medicated drops.

In addition to medications for the treatment of infectious (bacterial or viral) conjunctivitis, the person also needs to:

• Keep hands away from eyes.

• Wash hands frequently.

• Do not share eye medications, towels or washcloths.

• Remove discharge with moist cotton balls or a warm, wet washcloth and discard after using.

• Use cool compresses to help relieve the symptoms.

• Change towel and washcloth daily.

• Wear clothes only once before washing.

• Change pillowcase each night.

Noninfectious Conjunctivitis

Allergic conjunctivitis can be treated by:

• Removing the allergens that are causing the problem.

• Applying cool compresses to the eyelids to alleviate symptoms.

• Using drops (such as Artificial Tears).

  If these are not effective, use topical nonsteroidal eye drops (such as Acular) or topical antihistamine drops (such as Vasocon-A or Livostin).

Oral antihistamines and topical corticosteroids also have been effective in managing allergic conjunctivitis.

Chemical conjunctivitis, caused by industrial or household cleaners entering the eye, is treated with prompt and thorough washing of the eyes with very large amounts of water and going to the doctor for examination.

For conjunctivitis caused by smog or pollutants, treatment consists of using over-the-counter eye drops to relieve the red and irritated eyes.

Disease-based conjunctivitis is treated according to the treatment methods outlined for the particular disease.

Subconjunctival hemorrhage will disappear on its own. This condition is usually caused by forceful laughing, vomiting, diving under water or bending upside down.

If any of the symptoms outlined on these pages persist or worsen, see an ophthalmologist immediately.

Questions to Ask Your Doctor

Can a regular doctor treat conjunctivitis or should I see an ophthalmologist?

Will any tests or smears need to be done to identify the cause?

What type of conjunctivitis is it?

What is the best treatment?

How long will it take for relief of symptoms?

How long is the child with conjunctivitis contagious? Should she or he stay home from school?