Do you suffer from itchy, red, watery eyes? Allergic conjunctivitis, sometimes known as “red eye”, affects approximately one in five persons. It is caused where the body mistakenly believes that an outside substance such as pollen is a harmful invader. The conjunctiva (membrane covering the white of the eyes) release histamines and other chemicals as a response to the perceived invader and this causes the area to become inflamed.
Seasonal allergic conjunctivitis (SAC), as the name suggests, only affects sufferers at certain times of year, and is brought on by exposure to pollen. Those affected often display symptoms of hay fever at the same time. However, eye allergy can affect some people all year round, in what is known as perennial allergic conjunctivitis (PAC). This is brought on by allergens other than pollen, most commonly dust mites. Pet dander, pollution particles, chlorine, mold and some cosmetics and perfumes can also trigger PAC. These are the two most common eye allergies and although they can cause irritation and discomfort, they are not likely to be too serious.
However, other “red-eye” conditions, such as vernal keratoconjunctivitis (VKC), which affects mainly young males, and atopic keratoconjunctivitis (AKC) , which affects mainly elderly males, are more serious and can cause permanent damage to the cornea (the front transparent part of the eye which is very important for good vision). Thankfully these two conditions are both quite rare. Contact lenses can also cause a type of conjunctivitis known as giant papillary conjunctivitis (GPC). This is not caused by the lenses themselves but by particles which accumulate on the surface of the lens.
The commonest symptom of eye allergy is itchy eyes. Other symptoms include slight swelling of the eye lids, watery eyes, a burning sensation in the eyes and redness. In cases of SAC or PAC some or all of these symptoms will often be accompanied with a blocked or runny nose and sneezing.
If, in addition to these symptoms your eyes are producing thick mucus, if you feel like you have something in your eye, or are irritated by light then it is possible that you may be suffering from VKC or AKC and you should go to see your doctor immediately.
Symptoms of GPC for those who wear contact lenses, also often involve the production of mucus, as well as possible blurred vision.
If over-the-counter medicines do not cause your symptoms to stop after a few days or if you experience any of the more serious symptoms, such as mucus in your eyes then you should make an appointment to see you doctor, who may refer you for further investigations.
You are likely to be asked about whether you or any close relatives suffer from other allergic conditions such as hay-fever, eczema or asthma. You will be asked about the circumstances in which symptoms appear. This may be enough to work out what is causing the allergic reaction.
The eye may be closely examined and sometimes a tiny sample of cells may be taken by carefully scraping the inner lining of the eye. These will be sent to the lab to test for allergies.
Management of Eye Allergy
The first and most important step in managing an eye allergy is to do your best to avoid the triggers.
If you suffer from SAC you should try to avoid pollen. Check weather websites or bulletins for when the pollen count is high and when this is the case you should try to stay indoors with the windows closed and the air conditioning turned on. Do not open car windows. If you have to go out wear wrap-around sun glasses to reduce the amount of pollen getting into your eyes.
If your eye allergy is not just seasonal then it is important to identify the root or roots of the problem. If, as with many people, your allergy is triggered by dust mites then it might be a good idea to buy mite-proof bedding. Mattresses, pillows and duvets should be aired every week and replaced regularly. Wash all bedding frequently at temperatures of at least 130 degrees fahrenheit (55 degrees centigrade). It is worth replacing carpets and rugs with hard surfaces such as wood or floor tiles which can be wiped down with a wet mop. Avoid sweeping as this tends to help mites to circulate in the air. Use blinds instead of curtains and replace any old fabric covers on furniture and cushions. If your allergy is triggered by pet dander, for example where your eyes are worst around cats, make sure that there are pet-free zones in the house, particularly your bedroom. Try to avoid touching the pet and keep it outside as much as possible. If you must touch the pet, wash your hands immediately afterwards. Ensure the animal is brushed down regularly by somebody who does not suffer from allergies. If your allergy is caused by mold, you might think about buying a dehumidifier. Keep bathrooms and kitchens well aired and spotlessly clean. It might help to spray the walls regularly with anti-mold treatment. Contact lens wearers who suffer from GPC might be advised to switch to wearing glasses or, if that is not acceptable, switching to daily disposable lenses. Depending on what triggers your conjunctivitis you might need to stop swimming in heavily chlorinated swimming pools or to throw away old cosmetics, especially mascara.
Do not rub your eyes. This will only make the condition worse. Try keeping an eye mask in the fridge to use when your eyes feel particularly itchy.
Sometimes it is just not possible to completely avoid being exposed to whatever causes your eye allergy, particularly as many of the particles that trigger a reaction are often airborne.
You might find that over-the-counter eye drops or artificial tears help clear things up but these should not be used for longer than a few days. Some have even been reported to have triggered a reaction in some people. If symptoms have not improved after a few days use of over-the-counter medicines or drops then you may need a prescription. Your doctor might decide to prescribe more effective eye-drops or tablets (antihistamine/ mast cell stabilizer/NSAID). If the eye is particularly inflamed the doctor may prescribe a short dose of corticosteroids.
You may even be referred for immunotherapy, sometimes known as allergy shots. This involves being exposed to tiny amounts of the allergen with the dose being gradually increased in the hope of building up a resistance to it. However this treatment can take many months and is usually only used where the allergy is particularly serious and does not respond to more conventional treatments.