What is Allergic Conjunctivitis?
Allergic conjunctivitis is one of the most common and treatable eye conditions in children and adults. Often called “pink eye,” it is an inflammation of the conjunctiva, the tissue that lines the inside of the eyelid and the white of the eyeball, and helps keep the eyelid and eyeball moist. Allergic conjunctivitis is not contagious
What are the triggers of Eye allergy?
Allergens that may be present indoors or outdoors can cause eye allergies. The most common outdoor airborne allergens are grass, tree and weed pollens. People who are sensitive to these allergens suffer from seasonal allergic conjunctivitis, the most common type of eye allergy.
Pet hair or dander, dust mites and moulds are the most common indoor allergens. These indoor allergens can trigger symptoms for some people throughout the year, resulting in perennial allergic conjunctivitis. Cigarette smoke, perfume and diesel exhaust may inflame your eyes. They can act as irritants that cause non-allergic symptoms, or they can make your allergic response worse.
What are the types of Allergic Conjunctivitis?
Allergic conjunctivitis may be divided into 5 major subcategories.
Seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC) are commonly grouped together in Mild acute Allergic conjunctivitis or Hay Fever Conjunctivitis.
Vernal keratoconjunctivitis (VKC), atopic keratoconjunctivitis (AKC), and giant papillary conjunctivitis (GPC) constitute the remaining subtypes of allergic conjunctivitis, and are grouped together in Chronic Conjunctivitis.
1. Seasonal Allergic Conjunctivitis & Perennial Conjunctivitis
Seasonal allergic conjunctivitis occurs at the same time each year.Most cases are due to pollen and occur in the hay fever season.Symptomstend to last a few weeks each year and may vary withthe pollen countperennial conjunctivitis is a conjunctivitis that persists throughout the year (perennial means through the year). This is most commonly due to an allergy to house dust mite
2. Allergies to Animals
3. Vernal Kerato Conjunctivitis
VKC is a chronic bilateral inflammation of the conjunctiva, commonly associated with a personal and/or family history of atopy. More than 90% of patients with VKC exhibit one or more atopic conditions, such as asthma, eczema, or seasonal allergic rhinitis.
4. Giant Papillary Conjunctivitis
- This is uncommon. It is an inflammation of the conjunctiva lining the upper eyelid.
- It occurs in some people who have a small object on the eye – most commonly, a contact lens.
- It affects about 1 in 100 wearers of contact lenses. The exact cause of the inflammation is unclear -it is possibly an allergic reaction to debris caught behind a lens or to poor lens hygiene.
- It also sometimes develops after eye surgery.
5. Atopic Kerato Conjunctivitis
AKC is a bilateral inflammation of conjunctiva and eyelids, which has a strong association with atopic dermatitis. It is also a type I hypersensitivity disorderwith many similarities to VKC, yet AKC is distinct in a number of ways. Atopic dermatitis is a common hereditary disorder that usually has its onset in childhood;symptoms may regress with advancing age. Approximately 3% of the populationis afflicted with atopic dermatitis, and, of these, approximately 25% have ocular involvement.
6. Contact Conjunctivitis
Some people become sensitised to cosmetics, make-up, eye drops or other chemicalsthat come intocontact with the conjunctiva. This then causes an allergic response and symptoms of conjunctivitis.
In this condition the skin on the eyelids may also become inflamed. It is then called contact dermatoconjunctivitis.
What are the Symptoms of Allergic Conjunctivitis?
People affected by allergic conjunctivitis generally have a specific set of eye symptoms, including:
- Stringy or ropy discharge
- Redness of eyes
- Teary eyes with a watery discharge
- Mild sensitivity to light (Photophobia)
Are there any possible complications?
Seasonal and perennial conjunctivitis can be unpleasant, but complications are rare. Contact dermatoconjunctivitis and giant papillary conjunctivitis occasionally cause inflammation and ulceration of the cornea (keratitis). Some permanent loss of vision may occur if these are left untreated.
What is the treatment for Allergic Conjunctivitis?
The following can be useful whatever the cause of the allergic conjunctivitis:
- If you use contact lenses: in general, do not wear lenses until symptoms have gone, and for 24 hours after the last dose of any eye drop or ointment. However, your doctor or optician (optometrist) will advise if you can wear lenses with certain types of drops.
- Try not to rub your eyes, as this can cause more inflammation.
- Bathing the eyes with an over-the-counter ‘eye bath’ may ease symptoms.
- Avoid the cause of the allergy if possible. For example, if you have seasonal conjunctivitis then during the hay fever season try to avoid pollen by staying indoors as much as possible. Close windows, drive with windows shut and internal air circulation on in your car, and by wear wrap-around sunglasses when out.
Treatment for seasonal, perennial and animal-related conjunctivitis
In addition to the general measures described above:
Eye drops that reduce the allergic reaction are often prescribed. Tablets may also be prescribed. All medicines should only be taken under medical supervision.
Antihistamine eye drops - these are usually needed only twice a day. They have few side-effects and can be very effective in reducing symptoms.
Mast cell stabiliser eye drops -: these have been around for a long time. They are also very effective and relatively free from side-effects. They need to be used frequently, as they are shorter-acting: four times a day or more.
Combination anti-allergy drops - These combination drops are not suitable for everyone. For instance, children under 12 and patients with raised pressure in the eye (glaucoma) should not use them. Your doctor or pharmacist can advise if they are safe for you.
Antihistamine tablets - These are taken to try to generally lower the allergic response in your body
Steroid eye drops - Steroid drops are very effective in eye irritation. They calm down irritation and inflammation quickly. However, they increase the risk of eye infection, which can rapidly become severe in the presence of steroid drops. They can also lead to glaucoma. Therefore they should only be used if other treatments fail, and they are normally only used under the supervision of an eye specialist.
Eye drops and contact lenses - most drops contain preservatives. However, in some cases preservative-free versions are available, as the preservatives may also cause eye irritation or allergy! Soft contact lenses should not be worn whilst the drops are being used, as the preservatives can be absorbed into the lenses and can further irritate the eyes.
What should I look out for?
You should see a Qualified Allergist, if you are uncertain what is causing your symptoms and the symptoms do not settle within a few days. Also, see a Qualified Allergist urgently if any of the following occur:
- Symptoms change (for example, light starts to hurt your eyes).
- You have pain in the eye (mild soreness rather than pain is usual with conjunctivitis).
- Spots or blisters develop on the skin next to the eye.
- Your vision is reduced.
- The eye becomes very red – in particular, if it is on one side only.
Do’s and Don’ts of Allergic Conjunctivitis
- Drink adequate amount of water
- Use sunglasses
- Use cold compresses
- Increase intake of fruits
- Take prescribed medicines regularly, relapses are common in allergic conjunctivitis
- Drive with eyes uncovered
- Limit water intake
- Use steroid eye drops or any other medicines, without doctor’s consultation. Self medication can be very dangerous.