Conjunctivitis

Introduction:

The conjunctiva is a membrane that contains blood vessels and that lines the sclera (the white of the eye) and the inside surface of the eye lids. When it is inflamed the blood vessels get engorged and the eye has a "pink eye" appearance. The causes for such an inflammation can be a viral conjunctivitis, a bacterial conjunctivitis or an allergic conjunctivitis. Sometimes it is due to a small foreign body such as dust or metal etc.

Among viral illnesses measles, pink eye, herpes and shingles are common causes of an acute conjunctivitis. Bacterial infections such as the STD's (gonorrhea or chlamydia) are also common. More details can be found in the table below.

Signs and symptoms:

The signs and symptoms vary a lot depending on the underlying cause. See table below for the most common causes and links to more detailed texts.

Diagnostic tests:

Diagnostic tests depend on the clinical presentation and the history. Here is a more in depth text on this topic for the interested reader.

Various types of conjunctivitis
Name:	Cause and explanation:
viral conjunctivitis	most cases of conjunctivitis are due to a virus. This can cause pink eye on the one hand, which is self limiting. But it can also be caused from more severe viruses such as in measles conjunctivitis , herpetic conjunctivitis (herpes simplex) or shingles (herpes zoster)
bacterial conjunctivitis	bacteria cause a pussy (yellow or greenish) eye discharge. The danger is perforation due to ulceration
gonococcal / chlamydial conjunctivitis	in newborns these bacteria come from a contaminated birth canal; in adults they are sexually transmitted
allergic conjunctivitis	histamine release from allergic reactions and immune complexes can cause acute inflammation of the conjunctiva

Treatment:

Treatment is directed against the underlying cause. Depending on whether the conjunctivitis is acute or chronic and what the underlying cause of it is, the treatment will vary considerably as is detailed in these links from the Merck Manual (e.g. Ref.1 below and others).

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Eye diseases

Disclaimer:

This outline is only a teaching aid to patients and should stimulate you to ask the right questions when seeing your doctor. However, the responsibility of treatment stays in the hands of your doctor and you.

References:

2. Eye conditions: http://www.stlukeseye.com/Conditions/

3. Karolinska Institute Library eye disease links

Last Modified: Jan. 6, 2009