Atopic conjunctivitis

This is the most common form of allergic conjunctivitis and is frequently due to hay fever. There is often a history of allergy to pollen, grasses and other similar irritants, and there may be moderate discharge from the patient rubbing the eyes.

• an IgE-mediated hypersensitivity reaction caused by exogenous(pollen, grass, and weeds) allergens
• in the seasonal type, the episodes are seasonal: related to particular precipitant allergens of the season. In the perennial variety symptoms usually last the whole year (dust mite,etc) (1)

Immediate treatment consists of antihistamine drops and tablets, with cold compresses to relieve the itching. Local vasoconstrictors such as adrenaline may relieve the chemosis in the acute phase.

Longer term management involves the identification of the antigen and it's avoidance where possible. Fortunately, the attacks often moderate with age.

Reference:

1. http://www.emedicine.com/oph/topic85.htm