Pink eye (Conjunctivitis)
Introduction
Pink eye (conjunctivitis) is an inflammation or infection of the transparent membrane (conjunctiva) that lines your eyelid and part of your eyeball. The cause of pink eye is commonly a bacterial or viral infection, an allergic reaction or — in newborns — an incompletely opened tear duct.
Pink eye may make you feel as if you've got something in one or both of your eyes that you just can't remove. When you wake up in the morning, your eyes may seem to be pasted shut from the discharge coming from your eyes. The whites of your eyes may begin to have a pink discoloration, and you may not see as clearly as you did before.
Inflammation causes small blood vessels in the conjunctiva to become more prominent, resulting in a pink or red cast to the whites of your eyes. Pink eye and red eye are terms commonly used to refer to all types of conjunctivitis.
Though the inflammation of pink eye makes it an irritating condition, it rarely affects your sight. If you suspect pink eye, you can take steps to ease your discomfort. But because pink eye can be contagious, it should be diagnosed and treated early. This is especially important for preschool-age children, who commonly develop both viral and bacterial conjunctivitis.
Signs and Symptoms
The most common signs and symptoms of pink eye include:
- Redness in one or both eyes
- Itchiness in one or both eyes
- Blurred vision and sensitivity to light
- A gritty feeling in one or both eyes
- A discharge in one or both eyes that forms a crust during the night
- Tearing
Causes of pink eye include:
- Viruses
- Bacteria
- Allergies
- A chemical splash in the eye
- A foreign object in the eye
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.
Treatment
Your doctor may prescribe antibiotic eyedrops if the infection is bacterial, and the infection should clear within several days of starting treatment. Antibiotic eye ointment, in place of eyedrops, is sometimes prescribed for treating bacterial pink eye in children. An ointment is often easier to administer to an infant or young child than are eyedrops. With either form of medicine, you should notice a marked improvement in signs and symptoms within one to two days. Be sure to use the medication for the entire time your doctor prescribes it, to prevent recurrence of the infection.
Viral conjunctivitis can't be treated with antibiotic eyedrops or ointment. Like a common cold, you can use an over-the-counter remedy to relieve some symptoms, but the virus just has to run its course. You may notice a worsening of symptoms in the first three to five days. After that, your signs and symptoms should gradually clear on their own. It may take up to two to three weeks from the time you were infected for the virus to go away.
If the irritation is allergic conjunctivitis, your doctor may prescribe one of many different types of eyedrops. These may include antihistamines, decongestants, mast cell stabilizers, steroids and anti-inflammatory drops.
Prevention
Practicing good hygiene is the best way to control the spread of pink eye. Once the infection has been diagnosed, follow these steps:
- Don't touch your eyes with your hands.
- Wash your hands thoroughly and frequently.
- Change your towel and washcloth daily, and don't share them with others.
- Change your pillowcase often.
- Discard eye cosmetics, particularly mascara.
- Don't use anyone else's eye cosmetics or personal eye-care items.
- Follow your eye doctor's instructions on proper contact lens care.
Newborns' eyes are susceptible to bacteria normally present in the mother's birth canal. These bacteria cause no symptoms in the mother. In rare cases, these bacteria can cause infants to develop a serious form of conjunctivitis known as ophthalmia neonatorum, which needs treatment without delay to preserve sight. That's why shortly after birth, every newborn's eyes are protected with a preventative application of an antibiotic, such as erythromycin ointment.
Informations obtained from National Institute of Health.