Conjunctivitis

What is it?

Conjunctivitis, commonly known as "pinkeye," is an irritation of the conjunctiva. The conjunctiva is the moist, delicate membrane that lines the inside of the eyelids and covers the whites of the eyes. Conjunctivitis can be caused by a bacterial or viral infection, or it can be the result of an allergic reaction or chemical irritation of the eye.

In newborns, conjunctivitis that develops in the first two days of life can be caused by irritation from silver nitrate eyedrops. This irritation is not an eye infection - silver nitrate eyedrops are given at birth to prevent eye infections. Silver nitrate conjunctivitis usually begins within six hours to 12 hours after birth and resolves within two days.

Silver nitrate eyedrops are used in newborn babies because of possible exposure to bacteria during birth. Bacteria from the mother's vagina may pass into the infant's eyes during birth and cause bacterial conjunctivitis. In this case, the most common are the sexually transmitted bacteria Chlamydia trachomatis and Neisseria gonorrhoeae (the bacteria that cause gonorrhea). Both of these bacteria can cause symptoms of conjunctivitis in infants within the first two weeks of life, and both can cause serious eye damage. Herpes simplex virus from a mother's vagina can also pass to an infant during delivery. Besides causing viral conjunctivitis, herpes simplex virus can cause serious complications, including encephalitis (inflammation of the brain).

Many types of chemicals can irritate the conjunctiva and cause conjunctivitis. Spray perfumes, deodorants, household cleaners, smog, and industrial pollutants are some of the causes of chemical conjunctivitis.

Conjunctivitis can also be an allergic reaction. Allergic conjunctivitis can be due to something in the air, such as pollen or dust; something put into the eye, such as contact lens solutions; or something that a child has touched and then accidentally transferred to the eye.

Many types of bacteria and viruses can cause conjunctivitis in children. The most common bacterial cause of conjunctivitis is Haemophilus influenzae. Bacteria can pass from person to person through contact with infected body fluids and can also spread on a child's hands if she rubs or wipes her infected eyes.

Viral conjunctivitis can be caused by a number of different viruses, and it usually spreads through contact with contaminated tears or nasal fluids. Viral conjunctivitis can also be part of a broader group of symptoms when a child has one of the viral childhood infections, such as measles.

What are the symptoms?

All types of conjunctivitis cause redness of the eye (a "bloodshot" appearance), usually with itchiness or irritation.

In allergic conjunctivitis, the conjunctiva usually appears swollen and red. The eyes are also very watery, and itching is usually severe. In chemical conjunctivitis, depending on the chemical irritant, there can be severe eye irritation and pain.

In bacterial conjunctivitis, in addition to redness and itching of the eyes, there is usually a thick, sticky, yellowish discharge. The discharge may accumulate into crusts on the child's eyelids and may make the eyelids stick together after the child has been sleeping. In viral conjunctivitis, the eye discharge is usually clear and watery.

How is it treated?

Doctors can often determine the type of conjunctivitis by taking a careful history of when and how the child's eye symptoms began and by examining the child's eyes to look for specific signs, such as swelling or discharge.

Some cases of chemical conjunctivitis can be medical emergencies that require immediate action to prevent eye damage. If a chemical has gotten into your child's eye, flush the eye gently with cool, running water for at least 15 minutes. After covering the injured eye with a clean pad, take the child to the nearest hospital emergency department immediately. For some chemicals, flushing the eye alone may be sufficient to prevent eye damage, but it is important to follow up with your doctor.

If your child has allergic conjunctivitis, your doctor may treat her irritated eyes with decongestants or with eyedrops containing antihistamines. Cold compresses may also help relieve irritation. In some cases, your child may need to be referred to an ophthalmologist (eye doctor), who may prescribe stronger eye medications.

Bacterial conjunctivitis is treated with antibiotics, usually given as either eyedrops or as an ointment. With certain types of bacteria, oral antibiotics may be given. If you are caring for a child with bacterial conjunctivitis, it is important to give these medications for as many days as your doctor has prescribed, even if eye symptoms clear several days before the end of the treatment. This will prevent your child's conjunctivitis from coming back. If your child's eyelids are very sticky with yellowish discharge, you can use a clean cotton ball soaked in warm water to gently wipe the eyelids. Ask your doctor when your child can return to school.

Viral conjunctivitis cannot be treated with antibiotics effectively, but it usually clears on its own after a few days. As with bacterial conjunctivitis, viral conjunctivitis is contagious, so follow your doctor's advice about when your child can return to school.

How long does it last?

How long chemical conjunctivitis will last depends on the particular chemical irritant causing the problem and how it is treated. Simply flushing out the irritant with water can treat some types of chemical conjunctivitis; other types can cause severe or permanent eye damage.

Allergic conjunctivitis can sometimes be cured simply by eliminating exposure to the allergen. For example, reactions to a contact lens solution might be avoided by switching to a brand that doesn't include the irritating chemical. On the other hand, allergic conjunctivitis caused by seasonal allergies to pollen can last a whole season and return every year.

Bacterial conjunctivitis clears after a few days of antibiotic treatment, and there is rarely any permanent damage to the eye. (Eye infections caused by Chlamydia trachomatis and Neisseria gonorrhoeae need immediate medical attention to prevent permanent eye problems.) Viral conjunctivitis usually goes away on its own in a few days without further problems.

How can conjunctivitis be prevented?

Since there are multiple causes of conjunctivitis, there is no single way to prevent it. You can help prevent chemical conjunctivitis by keeping all chemicals, including perfumes and deodorants, safely out of your young child's reach. If your older child is working with chemicals at home or at school, make sure that she wears safety goggles to protect her eyes.

If your child has seasonal allergies, ask your doctor about ways to manage her symptoms. If your child's symptoms are severe, your doctor may suggest that your child be treated by an allergy specialist or an ophthalmologist.

To help prevent bacterial and viral conjunctivitis, remind your child to wash her hands frequently, especially if her school has an outbreak of "pinkeye." To prevent conjunctivitis from spreading among family members, make sure that an infected child never shares washcloths, towels, or pillowcases with anyone else. Wash these items well in hot water and detergent after your child uses them.

Conjunctivitis that occurs as part of other childhood viruses, especially measles, can be prevented by immunizing your child against these illnesses.

Pregnant women should ask their obstetricians to check that they have no active sexually transmitted diseases that might infect their infants, either before birth or during delivery.

When should the doctor be called?

Chemical conjunctivitis may be a medical emergency, depending on the chemical involved. If your child has gotten a chemical in her eyes, flush the area gently with cool, running water for at least 15 minutes. Then call your doctor or, if the irritation looks severe, take your child to the nearest hospital emergency department. Since most products containing dangerous chemicals are required to have emergency first-aid instructions on their labels, check the product's package for first-aid information, or call your local poison control center.

For other forms of conjunctivitis, call your doctor if your child has any of the following symptoms: eyes that are unusually red, itchy, or watery; eyes that look puffy or swollen; a thick, sticky, yellowish discharge from the eyes; or eyelids that look crusty or stick together when your child awakens.