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.

Symptoms

Allergic conjunctivitis causes itching, watering and redness of the eye. Most people with these symptoms also have allergic rhinitis (hay fever) which causes runny nose, itchy nose, sneezing, itchy and watery eyes and blocked nose and snoring.

Causes/triggers

Allergic conjunctivitis is triggered by the same allergens that trigger allergic rhinitis.

There are 2 types of allergic conjunctivitis/rhinitis.

1. Seasonal allergic conjunctivitis occurs in spring and summer. It is due to exposure to pollen and can be quite dramatic and debilitating. The pattern and plants causing it will vary from region to region. In Australia, grass pollen is the most common cause.
2. Perennial allergic conjunctivitis occurs all year round and is usually a milder form of conjunctivitis. There are usually also chronic nasal symptoms. In Australia, the most common cause is house dust mite. It can also be due to mould and animal allergens.
   Sometimes, in people allergic to animals, if animal hair gets into the eye by touching or rubbing, it can cause a very dramatic and severe sudden allergic reaction in the eye.

Diagnosis

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 show sensitivity to common allergens.

Management

Management begins with allergen avoidance where possible. 

Everyday Management of Allergic Conjunctivitis 

Here are some tips for managing allergic conjunctivitis at home: 

• Avoid rubbing your eyes, as this can make symptoms worse. 
• Rinse the eyes with artificial tears or saline eye drops, available over-the-counter from a pharmacy. 
• Apply a cool, clean compress to relieve inflammation and discomfort. 
• Wear a hat and sunglasses for some eye protection from pollen. 
• Shower after coming in from outside, if pollen is a trigger. 

• Wash your hands before touching your eyes, especially after handling pets or other allergens, such as plants including grass. 

However, even though people do what they can to reduce contact with allergens in the environment, many people will need medication. Most treatments for allergic conjunctivitis are available without prescription from the pharmacy. Most common forms of conjunctivitis are treated with antihistamine eye drops which are highly effective and long acting. Drops are more effective than oral antihistamines in this condition. Other types of eye drops are also used to treat allergic conjunctivitis such as anti-inflammatory eye drops and drops to shrink swollen/blocked blood vessels. Speak with your pharmacist or doctor about the best treatment for you.

Treating allergic rhinitis that is usually present also helps treat allergic conjunctivitis.

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 July 2023

Content updated July 2023