For most people, spring is a beautiful and pleasant season. But if you suffer from itchy eyes and excessive tearing every time this season comes and others often ask you why your eyes are red, you probably will not be happy for spring.
Eye allergies are one of the most common causes of referrals to ophthalmologists’. On average, one in every 10 to 15 people experience symptoms of eye allergies in their lifetime. The symptoms of eye allergies vary from person to person and a wide range of symptoms include mild burning and itching eyes to other severe, annoying, and sometimes dangerous symptoms. Moreover, eye allergies are often accompanied by other allergic symptoms such as hay fever (runny nose) and skin allergies (such as atopic dermatitis). The pollen of flowers and plants, hair and linter of animals, medications and cosmetics have main role in creating eye allergies. Often, eye stimulation caused by stimulants (such as smoke or dust) results in symptoms that are confused with eye allergy.
Why Are the Eye an Easy Target to Eye Allergies?
The eye is the window to the outside world. When the eyes are open, the conjuctiva is directly in contact with allergic materials in the air. The conjuctiva, the mucous membrane covering the front of the eye and the inner surface of the eyelid, is a protective barrier against the outside environment. There are a large number of veins, immune cells and defense materials in the conjunctiva that protect the inner layers of the eyeball from infections and foreign factors. In addition, eye tears also have cells and immune agents that help defend against external factors, so many defense reactions occur in front of the eyeball at the conjunctiva surface. Allergic reactions arise when natural control of these defensive reactions collapses or takes place instead of foreign factors against their own factors. The most important factors of creating allergic reactions ate the substances called “Histamine” which is a group of immune cells called “mast cells”. Histamine causes itching. In addition, histamine results dilation of the existed veins in the conjunctiva, which also makes the eyes look red. However other substances except Histamine may also be involved in allergic reactions, Histamine is the most important mediator of allergic symptoms.
Who Are Prone to Eye Allergies ?
Basically, allergic reactions in young people (under age 30) are more common. In addition, there is an increased risk of allergy in people or in their family with a previous history of allergic diseases. Especially those who have allergies to hay fever (runny nose) and skin allergy (such as atopic dermatitis) are highly susceptible to eye allergies.
What Are the Symptoms of Eye Allergies?
As mentioned, the main mediator of the creation of symptoms of allergy is Histamine. Histamine secretion in the conjunctiva causes itching, burning and tearing. Also, histamine makes eye look red by dilation of veins. In addition, this substance causes some fluid to come from the veins into the conjunctiva and eyelid. In this case edema of the eyelid is caused. Eyelids may become so swollen that one can not even open his/her eyes. The accumulation of fluid in the conjunctiva causes this to look like it has fluid in it, besides sometimes the accumulation of fluid in the conjunctiva is so much that the conjunctiva tissue swells so that you can not close your eyes properly and looks like a big urticaria or blisters. Sometimes, especially when the cornea is susceptible, light sensitivity will cause.
Eye allergy usually involves both eyes. But sometimes symptoms of allergy occur only in one eye, especially when an allergenic particle enters into the eye, and person is rubbing the affected eye, the occurrence of symptoms may be higher in this eye than the other eye.
Types of Diseases Related to Eye Allergy
• Allergic Conjuctivitis
Rubbing an itchy eye is a natural reaction, but rubbing the eyes results in releasing more histamine and other allergy mediators, thus making the symptoms worse. So try as much as possible to avoid rubbing your eyes.
Conjunctival inflammation or conjunctivitis is the most common form of eye allergies. This disease is often caused by the sensitivity to the pollen of flowers and plants, which is why it is more common in the spring. But in people who are allergic to dust, mildew, hair and feather of animals, or chemicals or certain medications, allergic symptoms may be caused in every season of year. Seasonal allergic conjunctivitis is often associated with runny nose. Important symptoms of allergic conjunctivitis include itchy eyes, burning eyes, red eyes, excessive tearing, watery discharge from the eyes, and swollen eyelids and conjunctiva. Because most of the acute symptoms of the disease are due to the release of histamine in the conjunctiva tissue, selective treatment of these symptoms is the use of antihistamine eye drops. To prevent occurring of these symptoms, the stabilizing drops of mast cells can be used (we will discuss these medications below). Also in extreme allergic cases steroids can be used for a short time with the ophthalmologist’s prescription. Antihistamine syrups and pills are usually not effective for the patient's eye symptoms, but are used to control runny nose and sensitive skin symptoms.
• Atopic Dermatitis (Eczema)
Atopic dermatitis is a severe skin allergy which is accompanied with acute itching and often pretends to be in children and teenagers. Eye symptoms of this disease involve teenagers and young adults, especially males. The main eye symptoms of this disease is acute itching and redness of eyelids. Excessive tearing and flaky inflamed eyelids with mucous discharge are the other symptoms. The eyelids grow thick and hard and sometimes sensitive to light. This disease causes Leukoma and blurred vision, if treated inappropriately due to chronic itching and repeated scratching of the cornea surface by the rough surface of the eyelids.
Sometimes, consumption of some allergenic foods such as eggs, nuts, strawberries, tomatoes, eggplants, spices, milk and fish may worsen skin and eye symptoms of atopic dermatitis. In this case, removing these substances from the diet helps control the disease. Moreover, irritant factors in the air such as dust and mildew, hair of animals can also exacerbate the symptoms in affected people.
The main basis of curing this disease is making use of strong oral antihistamines to control itching. Using antihistamine drops, stabilizing drops of mast cells and, in severe cases, short periods of steroid drops, can control eye symptoms.
Sometimes, an eyelid microbial infection is raised by atopic dermatitis, which can aggravate itching and other eye symptoms. In this case, the treatment of infection by using drops and antibiotic ointments and repeated washing of the eyelids can help eradicate the infection and improve the symptoms.
Ocular symptoms of atopic dermatitis may affect the person for years. In addition, people with this condition are more likely to develop cataracts and corneal lesions than normal people. For these reasons, they should be regularly monitored by an ophthalmologist.
• Vernal Keratoconjunctivitis
Keratoconjunctivitis (conjunctival and corneal inflammation) is an uncommon disease that is common in tropical rural areas and in adolescents, especially in males, and is gradually improving before age 20. The disease usually begins in the middle of the spring, when the weather is warm, and it resolves after 2-3 months, and recurs again in the following year.
In this disease eyes start itching and the eyelids become swollen and heavy (due to that, sometimes the infected person found in sleepy appearance). Light sensitivity may be caused. Usually there is sticky white discharge in the corners of the eyes. Inside the upper eyelids are rough, bumpy, which can be easily seen during an eye examination done with an ophthalmic microscope and through everting the upper eyelid. Also, due to the accumulation of inflammatory cells in the conjuctiva, white spot may appear in the conjunctiva and around the cornea. Sometimes, in these patients, the conjuctiva tissue found prominent in the vicinity of cornea.
Due to excessive itching of the eyes, vernal keratoconjunctivitis can cause cornea scratched. The most effective treatment of this disease is the use of eye steroid drops (for a short time and by an ophthalmologist’s prescription). Mast cells and topical antihistamine drops can also be used to help control the disease and prevent recrudesce of the disease. Wearing sunglasses with large glasses and wide temples (which prevents dust from entering the eye) can control the disease. Also, using cold water compress and cooling the living place can relieve symptoms to some extent.
• Eye Allergies Due to Contact Lenses
Any foreign object, which is chronic in contact with the conjunctiva and the inner surface of the eyelid, can cause eye allergies. About the contact lens, the protein deposits created on the lens and lens cleaning solutions (especially existed preservatives in the solution) can lead to eye allergy. Sleeping with contact lens greatly increases the probability of eye allergies.
Sensitivity to the contact lens usually appears as redness and itching of the eye and causes excessive thick discharge from the eyes. On the underside of the upper eyelid usually occur bumps (these bumps are in fact the natural lumps of the conjunctiva called papillea, which expand abnormally as a result of eye allergies).
Stop using contact lenses is the most effective treatment for this type of allergy. Often, redness and itching of the eye will improve a few days to a few weeks after stopping the use of the lens, but the removal of eyelid bumps (papillae) may take several months. If one can not use glasses or other methods to improve vision and if that person needs to use a lens, some factors help to recover this phenomenon such as: change the type of lens, frequent cleaning the lens, and thoroughly rinse the protein deposits and then accurately drain with distilled water or use lenses which are replaced on a daily basis.
Furthermore, mast cell stabilizing eye drops are supposed to be used by these people for a few months (contact lens should be removed when using a drop).
• Eyelid Allergies
Eyelid allergy is often a type of sensitive virus reaction that is caused by direct contact with a particular allergenic substance. This is usually due to contact with detergents or cosmetics, and this is the reason of why it is more common in females. (Nail polishes can cause this condition if the eyes are rubbed with the hands).
Symptoms of this type of allergy usually happen between 24 to 48 hours after contact with the allergenic substances. Acute itching and redness of the eyelids often occur. There may be watery and small rashes on eyelids. Sometimes the conjunctiva turns red too. If the person is frequently in contacts with the allergenic substance, the skin of the eyelids thickens and becomes leathery.
best treatment of this complication is to identify the source of allergenic substance and then avoid it. In acute cases using a mild ophthalmic steroid ointment can help control symptoms for a few days. Infection with antibiotic medications should be treated if the microbial infection is added to the eyelid sensitivity lesion.
What Conditions Can Be Confused with Eye Allergies ?
In general, in cases which allergic symptom is more severe than usual or symptoms not resolved in the usual way, an eye examination should be done, because some of the serious eye diseases can first show similar symptoms with allergy.
Many eye diseases can be confused with allergies. The most common diseases are:
• Dry Eye: It usually causes eyes irritation and foreign body sensation. In this disease, itching is less than allergic diseases. In addition, dry eye usually affects the elderly people, while allergies occur in younger ones. An important point is that antihistamines which used to control allergic symptoms can worsen dry eye.
• Tear Duct Blockage: in this condition, due to tear duct blockage the eyes start tearing, but unlike allergic diseases there is no usually itching. It is more common in older people.
• Infectious conjunctivitis: Infectious conjunctivitis caused by diseases and viruses can lead to symptoms similar to eye allergies. Diagnosis of infectious conjunctivitis is more important than eye allergies, because the infectious conjuctivitis, especially its viral type, is highly contagious and can affect people around them.
In general, in cases which allergic symptom is more severe than usual or symptoms not resolved in the usual way, a thorough eye examination should be done, because some of the serious eye diseases can first show similar signs with allergy.
How to Treat Eye Allergies?
• Allergen avoidance: The best and most effective treatment of the eye allergy is to avoid contact with the allergenic substance if you can identify it.
• Cleaning and improving living place: keeping the house clean to minimize existed dust, avoid keeping pets, maintaining adequate humidity in the air and cooling the air at home, and using filters that absorb dust can control the allergy symptoms.
• Avoid rubbing your eyes
• Cold compress: Cold compresses reduce eye irritation and itching and usually have a soothing effect.
• Using appropriate medications
• Allergy Therapy: in certain cases, it may be possible to change the reaction of the immune system response to a specific substance and prevent occurrence of symptoms of allergy in affected person by methods such as inoculation of an allergenic substance and gradual increase of its value. Indeed, Of course, this method is costly and time-consuming and is not possible in many cases.
What Medications Are Used to Treat Eye Allergies?
• Artificial Tear Drop (Hypromellos)
Although this kind of drop has no direct effect on allergy treatment, the use of it will dilute the accumulated allergenic materials in the eye. In addition, to some extent, it does not allow the allergenic materials to stick on the surface of the conjunctiva and improves the defensive performance of the tear layer. The benefit of these drops as auxiliary treatments, especially in those who have allergies to dry eye conditions, and sometimes has wonderful beneficial effects.
• Antihistamine and Decongestant Drops
Do not use antihistamine and decongestants like Nephazoline drops + Antazoline drops for more than one or two weeks, because Long-term use of these drops can cause irritation and redness of the eyes, and the eyes may even become red in the absence of the drops. drops neutralize the effect of histamine in the conjunctiva and reduce itching, but they do not deal with swelling and redness of eyes.
Antihistamine eye drops have two major advantages over types of oral antihistamines: First, these drops are more effective than pills and syrups. Second, taking medication in the form of drop causes dry eye less than oral intake.
Decongestant drops reduce eye redness, therefore, the eye of the person apparently improves, but these drops do not have any effect on itching. These medications can strain the veins of the conjuctivia, resulting in reduction the redness of the eye. Providing long-term use these drops can cause irritation and redness. Furthermore, after several days of continuous use, the eye will get used to these drops and the eye may even become extremely red by the lack of the drop and then drop will have no effect on the eyes. So these drops should not be used sequentially for more than one or two week in any case. Decongestant drops in people suffered from glaucoma may be dangerous. Therefore, they should never consume these drops without doctor’s prescription.
In some pharmaceutical products, such as Nephazoline + Antazolin, antihistamine and decongestants have been combined. Consumption of these drops can control the redness and itching of the eye within a few minutes, and usually this effect remains for 3 to 4 hours. So, it can be used to treat the acute symptoms of allergies and its short-term use is not a serious problem (except eye irritation when using the drop). But as mentioned, their long-term use is not suggested and may have some side effects.
• Stabilizing Drops of Mast Cells
As mentioned, the main factor of creating allergy is a substance called "histamine", which is released from a group of immune cells called "mast cells". The stabilizing medications of mast cells do not allow histamine to be released from mast cells and thus prevent appearance of allergic reactions. These medications are effective in all types of allergies. Persons affected by seasonal allergies and vernal keratoconjunctivitis can make use of these drops one or two week before the start of season, in order to prevent the occurrence of symptoms of the allergy. Because these medications are relatively without sequel, their consumption can be continued for a long period (for example, a few months) without any particular problem. It should be noted, however, that the effect of these medications is relatively slow, and it usually takes a few days to treat these medications. Of this group, Cromolyn Sodium can be referred. Indeed, stronger and more effective medications are available from this category.
• Non-Steroid and Anti-Inflammatory Drops
These drops by anti-inflammatory effect cause a reduction in allergy symptoms, especially itching. But their long-term use can aggravate the irritation and itching of the eye. From this category of medications, Voltaren Droplet (Diclofenac) is mentioned.
• Steroid and Anti-Inflammatory Drops
These drops, such as betamethasone, prednisolone and dexamethasone, are very productive in treating ophthalmic sensitivities, but due to potential sequels of their use, they are limited to extreme allergies that do not cure with conventional methods. Due to the possible sequel such as cataracts and glaucoma, these medications should be taken according to your ophthalmologist’s prescription for a short time.
• Oral Antihistamines
Consumption of oral antihistamines is usually not effective in the treatment of eye allergies, but in cases where runny nose or skin allergies (especially atopic dermatitis) is associated with eye allergies, oral antihistamine can help control these symptoms.
• Remember that allergy is a chronic disease and this may occur repeatedly.
• Allergies are annoying but usually are not dangerous.
• In severe eye allergies you should be referred to an ophthalmologist.
• Treatment of acute allergies by using antihistamine-decongestant drops in a short period of time helps improve symptoms.
• In chronic allergies, the best medicine for long-term use is stabilizing mast cell drops.
• Steroid drops should be taken for a short period by an ophthalmologist’s prescription. Avoid using these medications without permission (betamethasone-dexamethasone-pronizolone).
• Cool drops usually relieve the itching of the eye. Keep eye drops in the refrigerator.