What is the difference between allergy inflammation and infection
- Bathing the eyes with cooled boiled water will give comfort as the condition improves.
- Some plants will also cause contact allergy, including Grevillea ‘Robyn Gordon’, African violets and a number of bulbs. Since the Rhus tree has been declared a noxious weed the number of cases of this serious contact allergy has declined.
- Usually there is an initial improvement of the condition after prescribed eye drops are used and then a continuing deterioration, only improved by ceasing the eye drops.
- Other causes include antibiotics (particularly neomycin) and the preservative thiomersal (a preservative in eye drops).
- Many cosmetics (especially nail polish), will cause a contact allergy of the eyelids, which may happen in only one eye
- A doctor will generally use patch testing to confirm the diagnosis and inquire about whether any non-prescribed or herbal drops own been used.
Contact lenses may cause symptoms
- It generally occurs in soft contact lens wearers, but is occasionally seen in hard lens wearers, andmay be due to the lens material itself, or the lens cleansing material, which contains thiomersal.
- Giant Papillary and Giant Follicular conjunctivitis (GPC or GFC), can happen in contact lens wearers and is similar in appearance to vernal keratoconjunctivitis.
- Sometimes the condition improves with a decreased wearing time, occasionally changing the lens to another polymer or soaking the lens in sterile water after an antibacterial solution.
Treatment depends on severity and cause of symptoms
Identifying and removing the cause of allergic conjunctivitis, where possible, is ideal when an allergic cause has been confirmed from allergy testing.
- House dust mite minimisation measures in the bedroom (removing carpet, using barrier encasing of pillows and mattress, washing bedding in boiling water).
- Removing the cat from the home in sensitive individuals.
It is also significant to exclude the presence of a foreign body such as dust, wood chip or an insect/s.
Symptoms of allergic conjunctivitis are generally mild to moderate and reply to bathing eyes with freezing water, ice packs and freezing water compresses.
Topical lubricants can also assist flush allergens from the tear film.
However, symptoms can sometimes be extremely severe and debilitating and require medication. Treatment options include:
- Oral antihistamines (tablets)
Help some people when avoidance measures are hard. However, they may dry the eyes, nose and mouth, and may cause blurred vision.
Antihistamines are generally contraindicated in glaucoma and advice should be sought from an eye specialist.
- Mast cell stabilisers are generally well tolerated, however, as they can take three to seven days to show an effect, they should be used to prevent symptoms before they happen and can be used as endless as necessary.
- Steroid eye drops — are effective quickly in relieving symptoms, but are associated with cataract formation, glaucoma and bacterial and viral infections of the cornea and conjunctiva.
They should only be used short term, only under medical supervision and never in the presence of herpes infections.
- Topical vasoconstrictor eye medications twice daily own minimal side effects, unlike nasal vasoconstrictor medications, but rebound vasodilation encourages overuse.
- Antihistamine eye drops in conjunction with a vasoconstrictor minimise itch and remove redness, but should not be used for longer than 14 days without medical advice.
- Antihistamine eye drops are effective but should not be used for longer than 6 weeks without medical advice.
- Mast cell stabilisers/antihistamines are quick acting, effective and generally well tolerated.
- Allergen immunotherapy for specific allergens
May benefit people with persistent, severe allergic conjunctivitis.
However, relief of eye symptoms takes longer than nasal symptoms.
Inflammation of the cornea can also be associated with allergy
The cornea has extremely few blood vessels (that is why it is clear), and is seldom involved in an allergic reaction. However, there are a number of causes of little pinpoint defects in the cornea, a condition called epithelial keratitis, which is generally due to drug and chemical exposure, for example:
- Vernal (allergic) conjunctivitis.
- Drug toxicity and drug allergy.
- Contact sensitivity to topical eye medications such as neomycin, idoxuridine, atropine and derivatives, thiomersal and some topical anaesthetics.
Specific conditions involving the cornea, which are associated with allergy are listed below.
- If the photophobia is severe, it can be hard for people to open their eyes in direct sunlight.
- The conjunctiva may be swollen, red and with a tenacious clear or pus containing discharge.
- The condition can persist for numerous years and causes severe photophobia, weeping and itching.
- Usually results in red, scaly and weeping skin of the eyelids.
- Secondary infection with Staphylococcus aureus is common and may cause infection of the eyelash follicles.
- A combined inflammation of the conjunctiva and cornea, most often associated with atopic dermatitis/eczema.
- Conjunctival scarring may happen if the persistent condition is not treated properly.
- Rigid lenses are necessary for excellent vision but they may irritate the inflamed conjunctiva.
- Vision is distorted due to the varying thickness of the cornea.
- Contact lenses may be necessary but they own specific problems in this condition.
- An inherited cone shaped thinning of the cornea frequently associated with atopic dermatitis.
- It is significant to consult an eye specialist should this condition be suspected.
- May be associated with the severe form of atopic dermatitis in about 8-10% of sufferers.
- Occurs in children and young adults, even in the absence of steroid therapy.
- Sleeping in an air-conditioned room, ice packs and freezing compresses can help.
- Usually starts in tardy childhood and is more common in boys than girls.
However the prevalence equals in the twenties and is rarely seen after the age of thirty. It generally lasts for between five to ten years.
- Treatment consists of intermittent short courses of topical or systemic steroids with ongoing topical cromolyn or antihistamine preparations.
- Frequently associated with allergic rhinitis, atopic dermatitis or asthma.
- It may be associated with a single allergen but more generally with multiple sensitivities.
- Usually affects both eyes and is severe, occurring seasonally and mainly in children.
- Rarely seen in freezing climates, more often in tropical and temperate climates.
- Results in nipple shaped protrusions on the inner aspect of the upper eyelid, often described as cobblestones and a stringy, tenacious mucus discharge.
- Moving to a cool climate is desirable, if possible.
What is conjunctivitis?
The conjunctiva is a layer of tissue which lines the front part of the eyeball (the white part of the eye) and the inside of the eyelids, but does not cover the cornea (the coloured looking part of the eye).
It helps to protect the eye from insults such as smoke, bacteria and allergens in the air, as well as the damaging effects of sun and wind. The eye is also protected by the eyelids, tears and cornea.
Conjunctivitis is an inflammation of the conjunctiva of the eye, which becomes red, swollen and produces discharge, in response to these insults. It can be caused by infection by bacteria or viruses, allergy and physical or chemical irritation.
Treatment depends on identifying the cause and severity of the condition.
There are several signs of allergic conjunctivitis
Typical signs and symptoms of allergic conjunctivitis include:
- Watery discharge, often accompanied by acute discomfort in bright sunlight light (photophobia).
- Itching and burning of both the eye and surrounding tissues.
- Redness in both eyes.
- The conjunctiva itself may become extremely swollen and glance light purple, and this may interfere with clarity of vision.
Eyelids may also be affected by an allergic reaction, causing the loose tissues of the lid to become swollen with subsequent drooping of the eyelid.
In cases of severe swelling, the lids cannot open and the gap between the upper and lower lids becomes slit like.
It is significant to note that blurred vision or corneal haze require urgent referral to an eye specialist.
Allergic conjunctivitis symptoms may be:
- Perennial (all year round) due to exposure to dust mite, animal dander, indoor and outdoor mould spores and occasionally foods or food additives.
- Seasonal due to airborne allergens such as pollen of grasses, trees and weeds.
Pollen allergy symptoms vary from day to day, depending on the weather, improving in wet weather and worsening on boiling windy days or after thunderstorms. There are also seasonal variations in some airborne mould spores, which may cause seasonal symptoms.
Red eye is a common eye problem
Red eye is one of the most common eye problems for which people visit a doctor. A description of symptoms and an eye examination by the doctor will generally propose the cause:
- Vision loss, discomfort in bright sunlight (photophobia) and pain propose more serious conditions, which should be investigated by an eye specialist (ophthalmologist).
- Itch and clear discharge suggests an allergic cause, possibly allergic conjunctivitis.
- Mild discomfort or burning often with excess watering may be due to dry eye.
- Clear discharge suggests a viral or allergic cause.
- Pus containing discharge generally indicates that there is bacterial infection.
- A gritty sensation is common in conjunctivitis, but the presence of a foreign body must be excluded, particularly if only one eye is affected.