It usually occurs when a person’s eyes come in contact with an allergen, a substance that causes the body’s immune system to overreact.
The eye becomes inflamed and reddened. Symptoms occur because the exaggerated immune system causes the body to release histamine and other active substances through mast cells. The blood vessels dilate or expand and this irritates the nerve endings.
The result is a greater secretion of tears.
Most people with allergies in the eyes have problems with both eyes.
Symptoms can appear quickly, soon after the eyes come in contact with the allergen. In other cases, for example, if the eye drops are causing a reaction, symptoms may appear after 2 to 4 days.
Symptoms of allergy to the eyes may be associated with other allergic conditions such as allergic rhinitis (hay fever) and atopic dermatitis (eczema). Cosmetics and certain medications are common triggers for eye allergies.
Eye drops, decongestants and over-the-counter antihistamines are often very effective in controlling the symptoms of eye allergy. In case of tearing, redness or severe eye pain, it is necessary for a doctor to perform an examination.
Symptoms of allergy in the eyes include:
Red or pink eyes: the eyes get irritated when the capillaries or small blood vessels widen in the conjunctiva.
Pain : This can affect one or both eyes. If a person has red-eye pain, is sensitive to light and his vision is affected, he should see a doctor immediately.
Itching : as the eyes are irritated, they can itch. Rubbing can make the itching worse.
Swollen eyelids: The eyelids may become inflamed when the conjunctiva becomes inflamed or if the person has been rubbing them a lot.
Pain : inflammation can make the whole area feel sore and sensitive. Some people say that the pain feels like burning.
People with seasonal eye allergy will experience symptoms at certain times of the year, usually from the beginning of spring through summer and sometimes through fall.
Those with perennial eye allergies are susceptible at any time of the year. You may find that the symptoms get worse at certain times of the day than at others.
If the eyelids are red, cracked or dry, this may indicate contact conjunctivitis. Contact conjunctivitis and giant papillary conjunctivitis are not seasonal, and symptoms can appear at any time of the year.
Causes of allergy in the eyes
An allergic reaction occurs when the immune system overreacts to a substance. Most people do not react in this way to dust, pollen and other substances, but some are more susceptible.
The following allergens commonly cause allergy in the eyes:
- Pollen, as in hay fever.
- Animal fur.
- Eye drops.
- Dust mites.
Types of allergy
There are different types of allergies in the eyes.
1) seasonal allergy or allergic rhinoconjunctivitis
Pollen is a common cause of allergies in the eyes and seasonal allergies. Pollen is the most common allergen to cause conjunctivitis in countries that have cold winters.
If conjunctivitis is the result of pollen, there are likely to be other symptoms, such as sneezing, itching, obstruction or runny nose, and itching of the eyes and eyes. Seasonal eye allergy or allergic rhinoconjunctivitis is also known as hay fever.
It usually occurs during the spring and summer months. At this time, the plants, and especially the grass, the trees and the flowers, are in pollen. Some people have symptoms during the early fall.
2) Contact conjunctivitis
Also known as contact dermatoconjunctivitis, the symptoms are usually caused by cosmetics, eye drops or other chemicals that irritate the conjunctiva in susceptible people.
Contact with these substances leads to an allergic response. Some people are sensitive to specific substances. Symptoms usually develop 2 to 4 days after the substance comes into contact with the eyes.
3) Giant papillary conjunctivitis
This often results from the use of contact lenses. In some people, contact lenses cause discomfort. This can progressively get worse and be more and more uncomfortable, causing the eyes to turn red.
Giant papillary conjunctivitis (GPG) can also occur when a person wears hard contact lenses after eye surgery. Poor hygiene when handling contact lenses, solutions and cases can contribute to eye infections.
4) Perennial conjunctivitis
Perennial conjunctivitis lasts all year. It is mainly due to an allergy to house dust mites. These are insect-like microscopic creatures that live mainly in bedding, upholstered furniture and carpets.
Dust mites eat skin cells thrown by people, and they love warm, humid environments.
Allergy to dust mites is an immune system response to a specific dust mite protein. This causes a variety of problems, such as conjunctivitis, stuffy or runny nose, sneezing, and contraction of the airways, such as in asthma.
Other causes include animal dander, small scales of animal skins or hair or bird feathers. These can cause an allergic reaction in some people.
A doctor will diagnose the allergy in the eyes by examining the patient and asking about the signs and symptoms, including sneezing and runny nose.
They may also need to rule out other conditions with similar symptoms. Anyone with the following symptoms should see a doctor immediately, as they may have a more serious condition:
- Painful eyes
- Sensitivity to light or photophobia.
- Eye sight problems.
- Very red eyes.
In addition to the allergy in the eyes, the eyes may turn red with the following conditions:
Infectious conjunctivitis : This is caused by bacteria or viruses. It may be related to the herpes virus and may indicate a sexually transmitted infection (STI).
Acute glaucoma : pressure builds up in the eye. Symptoms can appear quickly. Untreated acute glaucoma can cause loss of incurable vision.
Keratitis : the cornea becomes inflamed and occasionally ulcerates. Sometimes it can progress to scarring of the cornea, resulting in permanent loss of vision.
Iritis : this is an inflammation of the iris. If left untreated, the iris can adhere to the lens, preventing the vital drainage of fluid from the pupil. The result could be irreversible damage to the eyes.
The doctor will also check if any object or substance, such as an eyelash, may be causing the irritation. If the symptoms are severe or worsen, the doctor may refer the patient to an eye doctor or ophthalmologist.
Anyone who develops papillary conjunctivitis after a recent eye surgery will be referred to an ophthalmologist. The eye or eyes must be carefully monitored to ensure that the treatment is effective.
Complications of perennial or seasonal allergy are rare. Allergy in the eyes can affect a person’s quality of life, but usually does not have a long-term impact on health.
Sometimes complications can occur with dermatoconjunctivitis and giant papillary conjunctivitis.
The cornea can become inflamed. This is known as keratitis and can cause ulcers to form in the cornea. This increases the risk of scarring and the possibility of permanent loss of vision.
The symptoms of keratitis are:
- Intense pain in the eye
- Sensitivity to light.
- Blurry vision.
- A feeling that there is something in the eye.
- Crying eyes.
If these symptoms occur, the person should see a doctor.
The red eye can be a symptom of allergy in the eyes, the following can offer relief:
Avoid the allergen : keep the house clean, minimize soft furniture and stay indoors when the pollen level is high can help.
Artificial drops : these eye drops dilute the allergen and help eliminate it.
Avoid contact lenses : these should not be used until the symptoms have completely disappeared. After using any medication in the eye, wait 24 hours after the treatment is finished before using contact lenses.
Refrain from rubbing the eyes : rubbing can worsen inflammation. This can be difficult, as it is tempting to rub your itchy eyes.
Cold compresses : holding a wad of cotton soaked in cold water on the eyelid can soothe the eyes.
Pharmacological treatment includes antihistamines, mast cell stabilizers and, occasionally, corticosteroids.
Antihistamines can help relieve symptoms quickly, either as an oral dose or as eye drops. Antihistamines block the effects of histamines. The body produces histamines when the immune system reacts to a foreign substance.
Oral antihistamines for allergy to the eyes are cetirizine , fexofenadine and loratadine. Usually, they are taken once a day.
Antihistamine eye drops include Alaway and Zaditor. Eye drops will relieve symptoms in the eyes, but the oral dose will also help treat nasal discharge and other symptoms.
The most commonly prescribed ophthalmic antihistamine drops are azelastine, emedastine, and ketotifen. Apply to the eyes two or three times a day.
Some antihistamines can cause drowsiness. People who take them for the first time should refrain from driving or operating heavy machinery until they know whether the medication affects them or not.
Mast cell stabilizers
Mast cell stabilizers take longer to relieve than antihistamines, but once they start working, the effects last longer.
The most popular mast cell stabilizers are lodoxamide and nedocromil. They come in the form of eye drops.
Some patients take antihistamines and mast cell stabilizers. Antihistamines relieve symptoms before the mast cell stabilizers begin to work.
They are rarely prescribed, and only if the symptoms are severe. Corticoid is a steroid hormone produced by the adrenal cortex. As a medication, synthetic corticosteroids can reduce swelling and decrease the body’s immune response.
Corticosteroids work well, but they should be used with caution and only in the short term, because there may be side effects.
The best way to prevent allergic rhinitis is to find out what causes it and avoid the allergen. The common allergens are pet fur and pollen. If the allergy is caused by pets, try the following:
- Keep pets out of the bedroom.
- Brush them regularly and wash them every 2 weeks.
- Wash your bedding regularly.
If you visit a house where there is a pet, taking an antihistamine medication an hour earlier can help reduce symptoms.
If the pollen causes a reaction:
- Stay inside and keep the doors and windows closed when the pollen level is high.
- Avoid areas with lots of grass, flowers or trees.
- Use wraparound sunglasses to protect your eyes.
- Bathing and changing clothes after being outside.
- Try to have someone else mow the lawn for you.
If house dust mites cause a reaction:
- Avoid soft furniture, such as rugs and curtains.
- Use a vacuum with a HEPA filter.
- Choose antiallergic mattresses and bedding.
- Vacuum frequently and apply dust with a clean, damp cloth.