Allergic conjunctivitis is inflammation of the conjunctiva due to an allergy.  The conjunctiva is a clear mucous membrane covering the front part of the eye and the inner surface of the eyelids.  Allergens causing inflammation vary among patients.  This disorder is more common in patients with pre-existing allergic diseases, such as hay fever, asthma and eczema.


Allergic conjunctivitis is caused by a reaction in which patients develop antibodies to a specific allergen which bind to the surface of inflammatory mast cells.  Mast cells will then release inflammatory mediators, such as histamine, which promote the development of conjunctival inflammation. 

Common airborne allergens causing allergic conjunctivitis are pollen, grass and weeds.  Additional allergens include animal skin and secretions, cosmetics, perfumes, air pollution, smoke and dust mites. 

Allergic conjunctivitis is common and seen more frequently in areas of high seasonal allergies.  It typically affects about 20% of the population every year.   

Several disorders can present with a “red-eye” that may resemble allergic conjunctivitis.  Patients should be evaluated by a specialist if the diagnosis is uncertain. Allergic conjunctivitis has a favorable prognosis and resolves easily; however, it may reoccur.

Signs & Symptoms

Symptoms of allergic conjunctivitis include:  itching, eyelid swelling, tearing, sensitivity to light, watery discharge, and foreign body sensation.  Every patient may present with a different set of symptoms; however, itching is the most common feature.  

Patients may also have a personal or family history of allergic disease, such as allergic rhinitis, bronchial asthma or atopic dermatitis. 

Any patient with eye complaints should be evaluated by a specialist to determine the cause of the symptoms and the appropriate treatment.


Most cases of allergic conjunctivitis can be diagnosed by gathering a thorough history and a complete eye exam.  Typically, allergic conjunctivitis resolves readily. 

Rarely, severe cases may require the collection of a conjunctival sample to diagnose this condition.  In this situation, a work-up will be performed by a specialist.


The best treatment of allergic conjunctivitis is to identify and avoid the allergen causing the inflammation.  There are several over the counter treatment options that may be considered. 

Artificial tears are used initially to provide a barrier against the allergens and flush out allergens from the eye surface.  Using artificial tears also helps with decreasing the concentration of the inflammatory mediators present on the surface of the eye. 

Antihistamines may be used to decrease the amount of histamine present on the ocular surface.  However, this will only temporarily suppress itching and redness of the eye. 

Speak to your physician about the best treatment option available for you.


The best prevention of allergic conjunctivitis is avoidance of the inducing allergen.  Appropriate eye hygiene, including hand washing and proper contact lens care, can also help in preventing reoccurrences.   Prognosis of allergic conjunctivitis is very favorable. Consult your physician for additional information.