Allergic Eye disease, also known as Allergic Conjunctivitis which affects 30-40% of the population, is an uncomfortable condition that is all too common in children because of the nature and cause of the condition. At Eye Clinic London, we assess your eye condition properly, because in symptoms and discomfort it can be similar to other, more serious problems. It can also be difficult to pinpoint exactly what causes the condition, as there are a myriad of causes. Only a professional can safely identify the cause.
It can be a seasonal condition that only happens during the most allergen filled months of the year (which is called seasonal allergic conjunctivitis) or it can be a year round condition (called Perennial Allergic Conjunctivitis). The main eye symptoms are burning, itching, watering, red eyes and swollen eyelids. There is often runny nose, sneezing and coughing, itchy nose and throat, headaches and sinus congestion. In severe cases patients can suffer from fatigue and lack of sleep.
Seasonal Allergic Eye Disease
Symptoms are usually part of hay fever. The cause is pollens from grass, trees, weeds or shrubs to which the the sufferer has become allergic, landing on the eye surface triggering the release of substances like histamine which causes the symptoms. Much like an iceberg what you can visibly see of the symptoms is only the beginning. The part of the eye you can see when looking at the eye is not actually the part really affected, although it may redden and itch just as much as the rest. The cornea (the transparent window of the eye) is thankfully not affected at all and the surrounding white is only slightly affected. Most of the negative effect is found in the larger area underneath the eyelids.
Under the upper eyelid there is slight redness, swelling of the tissues and sometimes bumpiness. The relative lack of signs combined with the typical seasonal history and symptoms is what can really help to distinguish allergic eye disease from other kinds of inflammation like infections.
Perennial Allergic Eye Disease (year round)
Year Round Allergic Eye Disease is caused in the same way, but is usually caused by more constant sources of irritation, like house dust or indoor pets, such as dogs, cats and birds. In other countries, where it may be hot and dry, the same condition can be caused by different things.
Allergy tests are usually used to identify the trigger of allergic reactions, such as skin prick tests and blood tests, but they are sometimes unable to find the trigger for allergic conjunctivitis. The equivalent of the skin prick test for the eye is called the conjunctival provocation test. Although not often used, it can be beneficial in the diagnosis if other tests should fail. In this test extremely small amounts of the suspected allergen are introduced to the eye’s tear film and the effects noted.
Vernal Keratoconjunctivitis (VKC)
Other than the aforementioned Seasonal and Perennial conditions there are other, more serious but thankfully more rare allergic eye diseases. These are Vernal Keratoconjunctivitis (shortened to VKC) which occurs in severely allergic patients. This condition usually involves the cornea, which can be very serious as it threatens the child’s sight. Only an eye specialist (Ophthalmologist) is capable of dealing with this condition, alternative treatment is potentially dangerous and may result in vision compromise.
Managing Allergic Eye Diseases
The basic management for these diseases may seem simple, just avoid the allergen that causes the condition to flare up but it’s actually more complicated than that. First the allergen must be properly identified, which can only be achieved by taking a careful history from the patient. Many allergens are very common, making them difficult to avoid, so it is important to know exactly what is going on, especially if the patient suffers from the more serious VKC. Good ventilation, clean furniture, staying indoors on a day full of pollens in the air, keeping car windows closed during allergy season and air filters are all simple measures. Avoid rubbing eyes which help to release more histamine and make the condition worse.
Our specialist consultant may recommend antihistamine eye drops in the mild cases. Oral antihistamines suit many of the cases where the condition is associated with hay fever. An alternative is Mast Cell Stabilisers which come in eye drop form and have been used for several years safely and effectively for many patients with the condition from all kinds of backgrounds, really earning the treatment a gold standard as far as a “universal” solution. Steroids have been used in some cases, but unlike mast cell stabilisers, they come with potentially unwelcome side effects that may even, themselves, threaten the child’s sight. For these reasons, only a verified and registered eye specialist is capable of deciding when their use is absolutely necessary.
Immunosuppressive medication which is a new line of treatment is not needed for seasonal or perennial eye disease but may be needed in the management of VKC. It is reserved for those who need long term and frequent use of steroids. It should only be prescribed by our specialists. Whenever medication is being used for any condition, serious or otherwise, it is important to follow your specialists directions exactly to ensure the safety at all times and hopefully to ensure a quick restoration of eye health.