Conjunctivitis Health Article

Definition

Conjuctivitis is an inflammation resulting in redness of the lining of the white part of the eye and the underside of the eyelid (conjunctiva) that can be caused by infection, allergic reaction, or physical agents like infrared or ultraviolet light.

Description

Conjunctivitis is the inflammation of the conjunctiva, a thin, delicate membrane that covers the eyeball and lines the eyelid. Conjunctivitis is an extremely common eye disease because the conjunctiva is continually exposed to microorganisms and environmental agents that can cause infections or allergic reactions. Conjunctivitis can be acute or chronic depending on how long the condition lasts, the severity of symptoms, and the type of organism or agent involved. It can affect one or both eyes and, if caused by infection, can be very easily transmitted to others during close physical contact, particularly among children in a school or daycare setting. Other names for conjunctivitis include pink eye and red eye.

Demographics

Conjunctivitis is the most common eye infection of childhood. It occurs so frequently that records are not kept, so exact demographic information has not been amassed.

Causes and symptoms

Conjunctivitis may be caused by a viral infection, such as a cold; acute respiratory infection; or other disease such as measles, herpes simplex, or herpes zoster. Symptoms include mild to severe discomfort in one or both eyes; redness; swelling of the eyelids; and watery, yellow, or green discharge. Symptoms may last anywhere from several days to two weeks. Infection with an adenovirus, however, may also cause a significant amount of pus-like discharge and a scratchy, foreign-body-sensation in the eye. These symptoms may be accompanied by swelling and tenderness of the lymph nodes near the ear.

Bacterial conjunctivitis can occur in adults and children and is caused by organisms such as Staphylococcus, Streptococcus, and Hemophilus. Symptoms of bacterial conjunctivitis include a pus-like discharge and crusty eyelids after awakening. Redness of the conjunctiva can be mild to severe and may be accompanied by swelling. Persons with symptoms of conjunctivitis who are sexually active may possibly be infected with the bacteria that cause either gonorrhea or chlamydia. There may be large amounts of pus-like discharge, and symptoms may include intolerance to light (photophobia), watery mucus discharge, and tenderness in the lymph nodes near the ear that may persist for up to three months.

Conjunctivitis may also be caused by environmental hazards, such as wind, smoke, dust, and allergic reactions caused by pollen, dust, or grass. Symptoms range from itching and redness to a mucus discharge. Persons who wear contact lenses may develop allergic conjunctivitis caused by various eye solutions used and the foreign proteins contained in them.

Other less common causes of conjunctivitis include exposureto sun lamps or the electrical arcs used during welding and problems with inadequate drainage of the tear ducts.