Allergic conjunctivitis is inflammation of the white part of your eye and the inside lining of your eyelids due to allergies.
Key points about allergic conjunctivitis
- Conjunctivitis caused by allergies can be seasonal, occurring at certain times of the year (when due to pollen or grasses) or ongoing (when caused by dust mite or pets).
- Unlike bacterial or viral conjunctivitis, allergic conjunctivitis can't be spread from person to person.
- Allergic conjunctivitis usually affects both eyes.
- Symptoms can include red, itchy, watery, gritty eyes, puffy eyelids and a sore or burning sensation in your eyes.
- Treatment includes avoiding allergens and taking medicines to relieve your symptoms.
See your doctor or go to the nearest emergency department immediately if you or someone you care for experiences any of the following symptoms:
What are the causes of allergic conjunctivitis?
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.
What are the symptoms of 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 is usually not affected in 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.
How is allergic conjunctivitis diagnosed?
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.
How is allergic conjunctivitis treated?
Treatment of allergic conjunctivitis includes:
- identifying and removing the cause
- allergen immunotherapy.
Identifying and removing the cause
If your doctor has worked out what allergen is causing your symptoms, you need to minimise your risk of exposure to it, and where possible, remove it. Depending on the allergen, this may include:
- removing carpet, using barrier encasing of your pillows and mattress, or washing bedding in hot water to remove house dust mites
- removing pets from your house
- avoiding pollens by staying indoors during the hay fever season.
Medicines can be given by your doctor to relieve your allergic symptoms.
- Lubricating eye drops – these work to help lubricate your eyes and flush out the allergens. An example is Examples include PolyTears. However, preservative-free artificial tear eye drops are best, such as Hylofresh.
- Eye drops containing antihistamine or mast cell stabilisers – these help to remove redness and relieve itching. Examples include lodoxamide, cromoglicate sodium or Patanol eye drops.
- Eye drops containing steroids, a potent anti-inflammatory – these eye drops are usually used for a short period of time, as there is an increased risk of infection and glaucoma. They are usually prescribed by ophthalmologists. Examples include Flucon (FML), Maxidex (Dexamethasone), Prednisolone (Pred Forte).
- Oral antihistamines – these are used to relieve itching and nasal symptoms if you also have hay fever. Examples include loratadine and cetirizine.
A combination of these medicines may be given if your symptoms are severe. Ask your doctor, optometrist or pharmacist if you have any questions about any of these medicines.
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.
How can I care for myself with allergic conjunctivitis?
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.
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.
- Apply a clean cold facecloth or compress over closed eyes.
How can I prevent allergic conjunctivitis?
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.
The following links provide further information about allergic conjunctivitis. Be aware that websites from other countries may have information that differs from New Zealand recommendations.
- Allergic conjunctivitis Auckland Regional HealthPathways, NZ, 2018
- Allergic conjunctivitis DermNet NZ, 2015
- Specific allergen immunotherapy (AIT) for environmental (inhaled) allergies Paediatric Society of New Zealand and New Zealand Child & Youth Clinical Network, NZ, 2020
- Allergic conjunctivitis Patient Info, UK
- Castillo M, Scott NW, Mustafa MZ, Mustafa MS, Azuara-Blanco A. Topical antihistamines and mast cell stabilisers for treating seasonal and perennial allergic conjunctivitis Cochrane Database of Systematic Reviews. 2015; 6: CD009566.
- Calderon MA, Penagos M, Sheikh A, Canonica GW, Durham S. Sublingual immunotherapy for treating allergic conjunctivitis Cochrane Database of Systematic Reviews. 2011; 7:CD007685.
Dr Divya Perumal works at the Eye Institute and Auckland Public Hospital. She has expertise in performing eye surgery, including advanced glaucoma surgery and cataract surgery. She is a senior lecturer at the University of Auckland and is actively involved in teaching junior doctors and research, as well as conducting public lectures.