Allergies: Allergy conjunctivitis

Conjunctivitis is one of the most common and treatable eye conditions in children and adults. It is an inflammation of the conjunctiva, the tissue that lines the inside of the eyelid and helps keep the eyelid and eyeball moist.

Viruses, bacteria, irritating substances (shampoo, dirt, smoke, swimming pool chlorine), sexually transmitted infections (STIs), or allergens (substances that cause allergies) can all cause conjunctivitis. Conjunctivitis caused by bacteria, viruses, or STIs can spread easily from person to person but is not a serious health risk if diagnosed promptly. Allergic conjunctivitis is not contagious.

It is important to find out whether your conjunctivitis is caused by allergies or infection because each condition has different treatments. This article is about allergic conjunctivitis.

What are the symptoms of allergic conjunctivitis?

Symptoms of allergic conjunctivitis include:

• Redness in the white of the eye or inner eyelid.
• Increased amount of tears.
• Itchy eyes.
• Blurred vision.
• Swelling of the eyelid.

See your family GP if you have any of these persistent symptoms.

How is allergic conjunctivitis treated?

Allergy-associated conjunctivitis may disappear completely, either when the allergy is treated with antihistamines, or when the allergen is removed. Your GP may recommend you use one, or more, of the following:

• Mast-cell stabilisers: contain sodium cromoglycate and prevent the release of allergy causing chemicals, for example histamine, from cells in the body called mast cells. They are helpful in controlling symptoms over a long period of time and may take a couple of weeks before being effective. They are dispensed as eye drops.
• Antihistamines: reduce redness, swelling and itching by blocking the actions of histamine, the chemical that causes these symptoms of allergy. They are available both as eye drops and tablets.
• Corticosteroids: when other medicines fail, your GP may prescribe a course of steroid tablets to relieve the symptoms of conjunctivitis. These must be used with the supervision of your GP
• Immunotherapy: allergy injections can be effective for treating allergic conjunctivitis.

What can I do to relieve symptoms?

To relieve symptoms of allergic conjunctivitis:

• Remove contact lenses, if you wear them.
• Place cold compresses on your eyes.
• Try non-prescription artificial tears, a type of eye drop available over-the-counter that may help relieve itching and burning (Note: Other types of eye drops may irritate the eyes and should not be used.) Do not use the same bottle of drops in the other eye if it is not affected.

The best defence against allergic conjunctivitis is to go on the offensive: try to avoid substances that trigger your allergies.

Other tips:

• Don't touch or rub the affected eye(s).
• Wash your hands often with soap and warm water.
• Wash your bed linens, pillowcases, and towels in hot water and detergent to reduce allergens.
• Avoid wearing eye makeup.
• Don't share eye makeup with anyone else.
• Never wear another person's contact lens.
• Wear glasses instead of contact lenses to reduce irritation.
• Wash your hands before applying the eye drops or ointment to your eye or your child's eye.
• Do not use eye drops that were used in an infected eye in a non-infected eye.