Allergic conjunctivitis

Allergic conjunctivitis is inflammation of the conjunctiva(the membrane covering the white part of the eye) due to allergy. Although allergensdiffer between patients, the most common cause is hay fever. Symptoms consist of redness (mainly due to vasodilationof the peripheral small blood vessels), itchingand increased lacrimation(production of tears).

The symptoms are due to release of histamineand other active substances by mast cells, which stimulate dilation of blood vessels, irritate nerve endings and increase secretion of tears.

Treatment of allergic conjunctivitis is by avoiding the allergen (e.g. avoiding grass in bloom during the "hay fever season") and treatment with antihistamines, either topical (in the form of eye drops), or systemic (in the form of tablets). Cromoglicateis sometimes used topically.

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It uses material from the http://en.wikipedia.org/wiki/Allergic+conjunctivitis Wikipedia article Allergic conjunctivitis.