Pink eye affects the conjunctiva, the membrane lining the exposed surface of the eye and the inside surface of the eyelids, causing its namesake irritation.

Overview

Pink eye, medically known as conjunctivitis (kun-junk-te-VI-tis) is an infection or inflammation of the conjunctiva, the thin, protective membrane that covers the surface of the eyeball and inner surface of the eyelids. It is caused by bacteria, viruses and other germs that are transmitted to the eye through contaminated hands, towels, and eye makeup or extended wear contacts; by exposure to irritants such as chemicals, smoke or dust; or by pollen and other allergens. It is not uncommon for conjunctivitis eye to accompany a cold or flu.

Conjunctivitis is highly contagious -– and tends to be prevalent in daycare centers and schools -– spreading by direct person-to-person contact, in airborne droplets that are coughed or sneezed, or from sharing makeup, towels and washcloths. Its telltale sign is redness in the white of the eye that may be accompanied by increased tearing and/or a discharge that is watery or thick with mucus and pus and causes the eyelids to stick together.

Although usually a minor eye infection that improves within two weeks, some types can develop into serious corneal inflammation and vision loss if not treated quickly. If you wear contact lenses and suspect you have conjunctivitis, discontinue wearing your contacts until the condition clears; you may also need to replace your contact lenses to prevent recurrence.

There are four primary types:

• Bacterial conjunctivitis is the most common and serious type. It can affect one or both eyes and is usually accompanied by a heavy, yellow discharge. Caused by a variety of bacteria, including, staphylococci (staph) and streptococci (strep) and pneumococci, bacterial conjunctivitis is treated with antibiotic eye drops and typically resolves within 5 days. Children who are born to mothers with vaginal gonorrhea or chlamydia infections can develop conjunctivitis if contaminated secretions in the birth canal during vaginal delivery infect their eyes.

  Antibiotics are prescribed to help prevent the infection from spreading to the inner eye or other parts of the body, and impede infection to others. Warm compresses also help soothe the eye, and use of artificial tears will help clear discharges and dilute the bacterial toxins. Your eyecare provider may also recommend you scrub your eyelids with a solution made by adding 6 drops of tearless baby shampoo in 6 ounces of water.

• Viral conjunctivitis is usually caused by one adenoviruses, the family responsible for upper-respiratory illnesses such as colds, but can also result from herpes simplex, the rubeola virus that causes measles, Varicella-Zoster and other viruses. This type can also affect either one or both eyes, and usually causes a lighter discharge. Although viral conjunctivitis usually produces a superficial case that often clears on its own within two weeks, you should still see your eyecare provider to ensure it doesn’t lead to a more serious infection (keratoconjunctivitis) that can cloud the cornea.

  Antibiotics should not be used for this type -- they are ineffective and, in fact, could be dangerous. Your eyecare provider may recommend a topical and oral anti-herpetic medication that can help suppress herpes viral infections. A warm compress, with or without diluted baby shampoo, may relieve some of the discomfort. Artificial tears or over-the-counter decongestant eye drops can also be used.

• Allergic conjunctivitis results from a response to airborne pollen, dust, smoke, or environmental agents. Both eyes are usually affected and may itch, tear excessively and discharge a stringy mucous. You may also have other allergic reactions, such as a runny or itchy nose. Allergy tests can identify specific causes, and repeated injections may desensitize you to the allergens.

  Topical eye drops are available to relieve symptoms, and depending on the severity, you eyecare provider or physician may also recommend oral medications such as over-the-counter or prescription decongestant-antihistamines. Eyecare products such as contact lens solutions or eye drops can cause allergic reactions as well. Discontinue use if you notice allergic conjunctivitis symptoms following the use of a particular product.

• Chemical conjunctivitis is caused by exposure to irritating liquids, powders, or fumes and requires immediate action. Common irritants in include chlorine, detergents, fuels, ammonia, smoke and pesticides. First, flush the eye with cold water continuously for 15 minutes. Then, apply an over-the-counter product such as Visine for minor irritants such as chlorine from a swimming pool; for chemicals such as ammonia or bleach, emergency medical treatment is needed.

Symptoms

The primary symptom is redness and inflammation in the white part of the eye. In addition, you may experience:

• Swelling, burning and/or itching in one or both eyes
• Excessive tearing or water
• An eye discharge that forms a crust, especially at night. In viral conjunctivitis, the discharge is usually thin and watery; in bacterial cases, it tends to be green or yellow and sticky.
• Blurred vision or sensitivity to light
• A gritty feeling in your eye

Prevention

The best way to prevent viral and bacterial conjunctivitis is to wash your hands frequently and avoid touching your eyes. It’s also advised to never share towels, washcloths or eye makeup. If you are pregnant, you should get tested for sexually transmitted diseases such as gonorrhea and chlamydia to avoid eye infections of your newborn (although as a preventative measure, they are treated with antibiotic eye drops following delivery).

To prevent allergic or chemical conjunctivitis, you need to be aware of possible irritants. Besides tests to can determine allergic triggers, take steps to avoid exposure to irritants by keeping your environment well-ventilated, particularly when using products that produce smoke, chemicals or fumes, and by wearing protective eyewear and clothing when handling chemicals.

Treatment

If you suspect conjunctivitis, see your eyecare provider. Often, a culture checking for bacterial growth is performed. If it is positive, you’ll be prescribed antibiotic eye drops or ointment and likely experience relief within a few days; cases of viral conjunctivitis may take a week or longer to heal, and your doctor may suggest over-the-counter eye drops, although many cases clear on their own. Allergic conjunctivitis tends to take longer unless exposure to the allergen is identified and eliminated.

Prior to applying eye drops, wipe pus off the eyelids with a cotton ball dipped in warm water. If you are giving drops to a child, gently pull the lower lid down and place one drop (or a 1/4 inch ribbon of ointment) into the small pouch that this forms. Avoid touching the dropper or tube to the eye.

In addition to medication, you can treat the symptoms with warm compresses to relieve itching and burning and help remove the discharge. Applying a clean washcloth to your eyelids for 10 to 20 minutes, several times a day. Your doctor may also suggest you gently scrub your eyelids with a solution made by adding 6 drops of tearless baby shampoo into 6 ounces of water. Avoid swimming until the condition has healed.