Allergic conjunctivitis

Allergic conjunctivitis usually affects both eyes. Symptoms can include: 

• itchy, watery eyes
• puffy eyelids and swelling of your eyelids
• the white of your eyes looking red or pink
• sore or burning, gritty, irritated eyes
• other allergic symptoms such as the suddenly getting a blocked or runny nose
• in severe cases, your conjunctiva (the tissue that covers the surface of your eyeball) may swell, which is known as chemosis.

Your vision isn't usually affected by allergic conjunctivitis. However, if you are constantly exposed to an allergen and have long-term allergic conjunctivitis, your vision may become reduced. You may also develop large red bumps in the inner lining of your upper eyelid, known as papillae, and your cornea may be damaged by long-term inflammation.

There are several things you can do to improve your symptoms, including:

• not rubbing your eyes
• washing your eyes with cold water
• using cold packs or cold compresses on your eyes to soothe symptoms
• not wearing contact lens until your symptoms have cleared up
• using eye drops
• consider taking antihistamines if you have hay fever.

Identify and remove the cause

If you have worked out what allergen or irritant is causing your symptoms, you need to minimise your risk of exposure to it, and where possible, remove it. For example, removing carpet, using barrier encasing of your pillows and mattress, or washing bedding in hot water to remove house dust mites. Read more about how to prevent allergic reactions in the specific section on the allergies page.

Bathe your eyes with cold water, or apply cold-water compress 

Mild symptoms can be managed with bathing your eyes with cold water, or applying cold-water compress to the eye. The cold restricts circulation and will help calm down the inflammation that is associated with eye allergies.

• You can make a cold compress by dipping a flannel (face towel) in cold water, gently squeezing out some of the water and applying the cool flannel over your eyes. Repeatedly re-soak the towel to keep it cool or cold, until you get relief (10 to 20 minutes).
• If you apply a homemade compress using as a bag of ice, wrap the ice in a small towel or cloth. Don’t apply ice directly to the skin. It can cause frostbite.

How to wash your eyes

• Before touching your eyes, wash your hands with soap and warm water.
• Dry hands with a clean or disposable towel.
• Clean away any crusting or discharge with a disposable cotton swab and cooled boiled water. Don't use cotton wool balls because they can unravel, leaving cotton in your eye. Surgical swabs from your chemist or disposable eye make-up removal pads are best.

Use eye drops

There's a range of different types of eye drops used for eye allergies such as antihistamines and mast cell stabilisers. Some offer immediate relief, while others take a few weeks to be effective. Read more about eye drops for eye allergies.

When using drops or eye ointment, it is important to use the correct technique. This makes sure you get the right amount of medicine. Read more about how to use eye drops and eye ointment.

Antihistamine tablets or capsules

Antihistamine tablets or capsules are best used to relieve itching and allergy symptoms associated with the nose. While they can be mildly effective in relieving the itching associated with eye allergies, they may cause dry eyes and potentially worsen eye allergy symptoms. Read more about antihistamines.

Your doctor will ask you questions about your symptoms, including when you experience them and whether you have any allergies, asthma or eczema. Your doctor will also examine your eyes and check your vision. No tests are usually needed to diagnose allergic conjunctivitis. If you have chronic allergic conjunctivitis, your doctor may refer you for further eye tests to check your vision.

Allergic conjunctivitis can be caused by several things.

• Allergens in the air, such as pollen and moulds, are the most common cause of allergic conjunctivitis and are usually seasonal, eg, during the hay fever season of each year.
• Dust mites, animal dander and feathers usually cause ongoing allergic conjunctivitis when there is exposure to them.
• Direct eye contact with allergic triggers, such as cosmetics and preservatives in some eye drops and contact lens solutions, can cause allergic conjunctivitis when used.

The best thing to do to prevent allergic conjunctivitis is to prevent exposure to allergen.

• Don't rub or touch your eyes. If you touch anything you are allergic to and then touch your eyes, this can trigger allergic conjunctivitis.
• Wash your hands well before touching your eyes for any reason. 
• Change to low allergy eye products if your symptoms seem to come on after using eye make-up. Discuss options with your pharmacist. 
• Use your own flannel, towels, pillowcases and bed linen and change these regularly.