This a broad group of allergic conditions involving inflammation of the thin membrane that covers the inside of the eyelids and the eye, known as the conjunctiva. The commoner conditions are mild and do not affect the cornea, but the rarer diseases do involve the cornea and can be sight- threatening.
People with allergic conjunctivitis experience itching, watering and redness of the eye, and most people with these symptoms also have allergic rhinitis (or hayfever). Typically, seasonal allergic conjunctivitis follows exposure to pollen in the springtime and can be quite dramatic and debilitating. Perennial allergic conjunctivitis occurs all year round and is usually a milder form of conjunctivitis caused by more persistent exposures to allergens such as house dust mites.
Allergic conjunctivitis is triggered by the same allergens that trigger nasal allergies or allergic rhinitis. Seasonal allergic rhinitis is triggered by pollen in the air during Spring and early Summer and the pattern and plants causing it will vary from region to region. In Australia, grass pollen is the most common cause.
Perennial allergic conjunctivitis symptoms, usually accompanied by chronic nasal symptoms, are usually present most of the year. In Australia, house dust mite is the most common allergen causing this but exposure to mould and animal allergens may also be responsible.
Occasionally, in animal allergic individuals, introduction of animal hair into the eye by touching or rubbing can set off a very dramatic and severe acute reaction in the eye.
Diagnosis of Allergic Conjunctivitis is made by your doctor when typical symptoms are present, an examination of the conjunctiva reveals typical changes and allergy tests confirm the presence of sensitivity to common allergens.
Management begins with allergen avoidance where this is feasible but many people will require medication. Most common forms of conjunctivitis may be managed with specific antihistamine eye drops-the modern ones are highly effective and long-acting. Drops are more effective than oral antihistamines in this condition. Treating allergic rhinitis that is usually present also brings about a good response.
More serious forms of allergic eye disease must be managed by specialist eye doctors and allergy specialists.
For more helpful information on Allergic Conjunctivitis go to www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/allergic-conjunctivitis
Prepared by Prof CH Katelaris Oct 2012
Content updated October 2012