Eye Allergies: Types, Causes, Symptoms, and Treatments

How Common are Eye Allergies?

Eye allergies are very common across the world. According to Health Direct, over 1 in 5 people are affected by hay fever and eye allergies in Australia.

Unique types of eye allergies can affect different demographics depending on a range of factors, such as location and gender. According to Jordan Scott Masters, writing for the American Academy of Ophthalmology, eye conditions such as vernal keratoconjunctivitis occur most notably in hot and dry climates such as West Africa and disproportionately affect males under the age of 25.

1. Perennial Allergic Conjunctivitis

Perennial allergic conjunctivitis is a type of eye allergy where an allergen that can be found all year round lands directly in the eye, causing an allergic reaction.

Perennial allergic conjunctivitis is different from other types of eye allergies because the cause of the reaction can be found in the household or outside world all year round. The substance that causes the allergies may be different for everyone and the symptoms of perennial allergic conjunctivitis are milder and less severe than seasonal allergic conjunctivitis.

Perennial allergic conjunctivitis is diagnosed by a doctor or eye health professional examining the eyes and finding symptoms such as redness, swelling or burning of the eyes as well as mild symptoms of other allergic reactions, such as a runny nose or sneezing. A person’s history of allergies and what causes their allergies may also be checked.

2. Vernal Keratoconjunctivitis

Vernal keratoconjunctivitis is a severe type of eye allergy and allergic reaction where a seasonal allergen lands directly in a person's eye and the person is severely allergic to the substance.

Vernal keratoconjunctivitis is different from other types of eye allergies because the symptoms of the allergic reaction are much more intense and severe in the eye, and in some cases may lead to permanent blindness if the condition is not properly treated, according to the American College of Allergy, Asthma and Immunology.

Vernal keratoconjunctivitis is diagnosed by a doctor or eye health professional examining the eyes for symptoms, such as itching, tearing in the eye as well as constant creation of a thick mucus, the sensation of there being something in the eye, a sensitivity to light, and hard, round bumps being clearly seen on the eyelid.

3. Seasonal Allergic Conjunctivitis

Seasonal allergic conjunctivitis, also known as SAC, is a type of eye allergy that occurs when an allergen, a substance that causes an overreaction in the body's immune system, lands directly in the eye. Seasonal allergic conjunctivitis is closely associated with hay fever and is most common during seasons of high pollen.

Seasonal allergic conjunctivitis is different from other types of eye allergies because it is specifically caused by allergens that occur in spring and summer seasons and is most commonly caused by grass and plant pollen instead of substances that can be found all year round.

Seasonal allergic conjunctivitis is diagnosed by a doctor or eye health expert examining the eyes for symptoms of SAC, such as red or itching eyes, dark circles under the eyes, runny eyes or a runny nose and other common signs of hay fever.

4. Contact Lens Hypersensitivity

Contact lens hypersensitivity is a type of eye allergy where the usage of contact lenses is causing an allergic reaction. Contact lens hypersensitivity is caused by the proteins in the tears binding to the surface of the lenses and irritating the conjunctiva.

Contact lens hypersensitivity is different from other types of eye allergies because it is directly caused by the usage of contact lenses or allergenic materials lining the eye.

Contact lens hypersensitivity is diagnosed by a doctor or an eye health professional by checking the eye for symptoms such as itching and redness of the eye, excessive mucus release and uncomfortable lenses.

5. Giant Papillary Conjunctivitis

Giant papillary conjunctivitis, also known as GPC, is a form of eye allergy where the inside of the eyelid begins showing the symptoms of an allergic reaction, redness, itching or swelling, and bumpy sacs inside the eyelid, called papules, begin forming.

Giant papillary conjunctivitis is different from other eye conditions because although it shares many symptoms and causes in common with contact allergic conjunctivitis, such as a possible cause of the allergic reaction being contact lenses, the reaction to the contact lenses is much more severe and if giant papillary conjunctivitis is not treated, it may result in permanent intolerance towards contact lenses or a separate eye condition called ptosis, or drooping eyelids.

Giant Papillary conjunctivitis is diagnosed by a doctor or an eye health professional by examining the eye for symptoms of an allergic reaction, such as itching or redness, and also by examining the inside of the eyelid to see if the surface is smooth or bumpy due to GPC.

6. Atopic Keratoconjunctivitis

Atopic keratoconjunctivitis is a type of genetic eye allergy that can occur all year round. Atopic keratoconjunctivitis is caused by a separate genetic condition called atopy, which causes the immune system to produce an excess of antibodies when the body reacts to the presence of an allergen. The people who suffer from atopic keratoconjunctivitis are most often older men.

Atopic keratoconjunctivitis is different from other types of eye allergies because it is a genetic condition that is directly tied to atopy and its symptoms. Atopic keratoconjunctivitis also affects the lower eyelid more noticeable than other conditions, such as vernal keratoconjunctivitis. Atopic keratoconjunctivitis that is untreated may lead to conditions such as keratoconus which will affect sight.

Atopic keratoconjunctivitis is diagnosed by a doctor or eye health professional examining the eye and finding symptoms such as light sensitivity, itching, burning eyes, red and swollen eyelids and tearing eyes.

1. Pet Dander

Pet dander is defined as the microscopic flakes of dead skin that fall off of household animals such as dogs or cats. Pet dander typically lingers or sticks to surfaces and can linger in an area for four to six months.

Pet dander is a cause of eye allergies because pet dander triggers the body's response to animal allergies if a person is allergic to that animal. This creates the chemical histamine in the system, which will cause red and watery eyes as well as welling of the eyelids.

2. Pollen

Pollen is a yellow-coloured powder produced by plants that releases during certain seasons in the year, with some seasons seeing a greater release of pollen than others.

Pollen is a cause of eye allergies because like many forms of allergens the body believes it is a harmful substance and overreacts when pollen comes into contact with the eyes or body, most noticeably releasing a chemical known as histamine that causes swelling, redness and watering in the eyes.

3. Mould

Mould is a type of fungal growth that occurs on organic matter that is decaying or has been wet for an extended period of time.

Mould is a cause of eye allergies because the body may react to certain specific types of mould spores in the air as the spores make contact with the eyes or skin. Not all types of mould cause an allergic reaction, most commonly, mould allergies are caused by mould types such as cladosporium or penicillium.

4. Smoke

Smoke is defined as visible particles, typically black or grey, in the air made up of small pieces of carbon and other particles, that is caused as a reaction to fire or other burning substances.

Smoke is a cause of eye allergies because smoke particles can cause irritation or an allergic reaction in the eyes. Smoke causes eye allergies because some bodies may consider the particles an allergen, which means that if smoke particles make contact with the skin or eyes, the immune system will overreact and create the chemical histamine in the body. Histamine causes swelling, watery and red eyes among many other side effects.

5. Dust

Dust is a powdered collection of many different types of particles. The source of these particles varies heavily and can come from skin flakes, animal skin, dust mites, dead insects and many others.

Dust is a cause of eye allergies because one of the sources of the particles that make up dust may be an allergen, and cause an allergic reaction in the body. Dust mites are also a common allergy that can typically affect those already prone to hay fever or seasonal allergies.

When do Eye Allergies Symptoms Usually Occur?

Eye allergy symptoms usually occur in the spring season or the time of year where there is the most pollen and grass particles in the air. These pollen particles are a major cause of many forms of allergies, and can cause eye allergies if they make direct contact with the eye.

What are the Risk Factors of Eye Allergies?

The risk factors of eye allergies are seasonal allergens, indoor allergens, genetic conditions and contact lenses hygiene. The risk factors of eye allergies are listed below.

• Seasonal allergens: Seasonal allergens are a risk factor of eye allergies that occur during the spring, summer and autumn seasons. Seasonal allergens include pollen from plants such as grass or flowers.
• Indoor allergens: Indoor allergens are a risk factor of eye allergies that occur all year round and can be found indoors. Indoor allergens include dust mites and dander from pet animals such as cats or dogs.
• Genetic conditions: Genetic conditions are a risk factor of eye allergies that occur when a person has a family history of certain allergies or eye conditions, such as atopic dermatitis.
• Contact lenses hygiene: Contact lenses hygiene is a risk factor of eye allergies when the contact lenses a person is wearing are not properly cleaned, are poorly worn or are worn for too long.

What are the Eye Allergies Complications?

Complications of eye allergies are long-term eye damage, scarring blood vessels and an inflamed cornea in severe eye allergies. The following are complications of eye allergies:

• Damaging the eyes: Damaging the eyes is a complication in eye allergies when a person may repeatedly touch, scratch or rub the irritated eye too aggressively or repeatedly, which may cause long-term damage to the eyes if done too often or too violently. Eye allergies on their own do not cause such damage to the eyes.
• Scarring blood vessels: Scarring blood vessels are a complication in eye allergies in rare circumstances and occur if the eye allergy is so severe that the symptoms cause new blood vessels to appear in the eye and leave scarring so intense that it may only be repairable by surgery.
• Inflamed cornea: Inflamed cornea is a complication in eye allergies that is medically known as keratitis. This causes damage to the cornea and can result in scarring and permanent blindness.

How are Eye Allergies Diagnosed?

Eye allergy symptoms are diagnosed by a doctor or eye health professional by examining the eye for swelling, itching, redness, tearing or watering eye and possibly rocklike bumps along the upper eyelid. A blood test or skin test may also be taken in order to diagnose eye allergies.

1. Antihistamine Eye Drops

Antihistamine eye drops are eye drops that contain proteins or chemicals such as a substance called ketotifen, which affect the mast cells and helps to reduce uncomfortable symptoms of histamine in the body.

Antihistamine eye drops treat eye allergies and their symptoms by blocking the mast cells from creating histamine, the chemical that causes eye allergy symptoms such as swelling, watery eyes or itchiness. when it senses an allergen is present in the eyes or skin. Antihistamine eye drops should not be taken for more than 6 weeks.

Before taking any form of medication to relieve symptoms of eye allergies, please consult a doctor or eye health specialist.

2. Mast Cell Stabiliser Eye Drops

Mast cell stabiliser eye drops are eye drops that contain chemicals such as ketotifen, nedocromil sodium or cromolyn. Over-the-counter Mast cell stabiliser eye drops typically only contain ketotifen and similar substances.

Mast cell stabiliser eye drops treat eye allergies and their symptoms by affecting the mast cell, a white blood cells that controls the release of histamine in the system. Mast cell stabiliser eye drops cause the mast cell to stop releasing inflammatory chemicals and affect the body's histamine receptors. Mast cell stabiliser eye drops do not immediately address itching and the uncomfortable effects of histamine like antihistamine eye drops do, they instead prevent itching and other allergy symptoms for an extended period of time.

Before taking any form of medication to relieve symptoms of eye allergies, please consult a doctor or eye health specialist.

3. Corticosteroid Eye Drops

Corticosteroid eye drops are steroid eye drops most commonly used by ophthalmologists or with an ophthalmologist recommendation and under strict instructions.

4. NSAID Eye Drops

NSAID eye drops are eye drops that contain anti-inflammatory drugs and chemicals that are non-steroidal, such as ibuprofen or aspirin.

NSAID eye drops treat eye allergies and their symptoms by granting immediate short-term relief to conditions such as inflammation in the eye and reducing swelling and redness.

Before taking any form of medication to relieve symptoms of eye allergies, please consult a doctor or eye health specialist.

Corticosteroid eye drops treat eye allergies by relieving inflammation, wetness of the eyes and redness of the eyelids. As a steroid eye drop, Corticosteroid eye drops should only be used with a specialised expert's advice and can have multiple side effects if used incorrectly or too often.

Before taking any form of medication to relieve symptoms of eye allergies, please consult a doctor or eye health specialist.

5. Non-Sedating Oral Antihistamines

Non-sedating oral antihistamines are medications that contain antihistamines substances but either have none or very little of the substances that cause drowsiness or sleepiness.

Non-sedating oral antihistamines treat eye allergies by preventing the production of histamine in the body’s system.

Before taking any form of medication to relieve symptoms of eye allergies, please consult a doctor or eye health specialist.

6. Allergy Shots (Immunotherapy)

Allergy shots, also known as immunotherapy, are injections sporadically taken three or more times a year. These injections contain traces of an allergen, but not enough to cause an allergic reaction.

Allergy shots treat eye allergies by helping the body adjust to the presence of allergens in the system. By adjusting the body to the presence of allergens, the immune system will stop recognizing the allergen as a substance that has to be expelled, and will stop triggering the mast cells into releasing histamine, preventing symptoms of eye allergies such as swelling and itching.

Before taking any form of medication to relieve symptoms of eye allergies, please consult a doctor or eye health specialist.

How Long will Eye Allergies Last?

Eye allergies typically last for 4 to 8 weeks or for as long as the pollen season may last.

Are Eye Allergies Curable?

Eye allergies are not curable and there is no medication that will completely eliminate the body and the eyes allergic reaction to allergens. However, there are methods and medications that can be taken to reduce the symptoms of eye allergies and on different occasions, the body grows past certain allergies as a person ages.

Are Eye Allergies Contagious?

Eye allergies are not contagious as they do not involve any bacteria that is spreadable in the allergic reaction, unlike other allergic reactions such as regular conjunctivitis.

What is the Difference between Eye Allergies and Eye Infection?

The difference between eye allergies and an eye infection is that eye allergies are caused by an allergic reaction to a foreign substance in the system that the body believes is hazardous, while an eye infection is caused by the body's reaction to more severe substances such as viruses, bacteria or parasites.

Eye infections also do not commonly cause eye itching. Itching is most commonly a symptom of eye allergies, according to John Hopkins Medicine, an American based medical research centre.