Conjunctivitis

Conjunctivitis, commonly known as pinkeye, is an inflammation of the conjunctiva, the clear membrane that covers the white part of the eye and the inner surface of the eyelids.

While pinkeye can sometimes be alarming because it may make the eyes extremely red and can spread rapidly, it's a fairly common condition and usually causes no long-term eye or vision damage. But if your child shows symptoms of pinkeye, it's important to see a doctor. Some kinds of pinkeye go away on their own, but other types require treatment.

What Causes Pink Eye (Conjunctivitis)?

Pink eye may be triggered by a virus, bacteria, an allergic reaction (to dust, pollen, smoke, fumes or chemicals) or, in the case of giant papillary conjunctivitis, a foreign body on the eye, typically a contact lens. Bacterial and viral infections elsewhere in the body may also may induce conjunctivitis.

What are the symptoms of conjunctivitis?

See your ophthalmologist (a doctor trained to treat eye conditions) or family doctor if you have any of these persistent symptoms. Ear infections also commonly occur in children who have bacterial conjunctivitis. The ophthalmologist will examine your eyes and possibly take a sample of fluid from the eyelid with a cotton swab. Bacteria or viruses that may have caused conjunctivitis can then be seen through a microscope.

Causes of pink eye include:

• Viruses
• Bacteria
• Allergies
• A chemical splash in the eye
• A foreign object in the eye

Most cases of pink eye are caused by viruses. In newborns, pink eye may result from an incompletely opened tear duct.

Viral and bacterial conjunctivitis may affect one or both eyes. Viral conjunctivitis usually produces a watery or mucous discharge. Bacterial conjunctivitis often produces a thicker, yellow-green discharge and may be associated with a respiratory infection or with a sore throat. Both viral and bacterial conjunctivitis are associated with colds. Both viral and bacterial types are very contagious. Adults and children alike can develop both of these types of pink eye. However, bacterial conjunctivitis is more common in children than it is in adults.

Allergic conjunctivitis affects both eyes and is a response to an allergy-causing substance such as pollen. In response to allergens, your body produces an antibody called immunoglobulin E (IgE). This antibody triggers special cells called mast cells in the mucous lining of your eyes and airways to release inflammatory substances, including histamines. Your body's release of histamine can produce a number of allergy symptoms, including red or pink eyes. If you have allergic conjunctivitis, you may experience intense itching, tearing and inflammation of the eyes — as well as itching, sneezing and watery nasal discharge. You may also experience swelling of the membrane (conjunctiva) that lines your eyelids and part of your eyeballs, resulting in what may look like clear blisters on the whites of your eyes.

Irritation from a chemical splash or foreign object in your eye is also associated with conjunctivitis. Discharge tends to be mucus, not pus. Sometimes, flushing and cleaning the eye to rid it of the chemical or object causes redness and irritation. Signs and symptoms usually clear up on their own within about a day.