Allergic Conjunctivitis

What is Allergic Conjunctivitis?

Allergic conjunctivitis, a common eye condition often overlooked, has been on the rise recently. It is one of the conditions doctors come across most often. This type of eye allergy can occur due to various reasons such as heredity, general inflammation, exposure to air pollution, an allergic reaction to an environment or substance (known as atopy), exposure to pollen and interactions with pets. While it’s mostly harmless, allergic conjunctivitis could potentially turn into keratoconjunctivitis, which might decrease vision. Although it’s rarely a threat to sight, allergic conjunctivitis can greatly reduce a person’s quality of life.

Allergic conjunctivitis can be broken down into three main types: acute, seasonal and all-year-round. It can also include conditions like seasonal allergic conjunctivitis (SAC), perennial allergic conjunctivitis (PAC), vernal keratoconjunctivitis (VKC), and atopic keratoconjunctivitis (AKC).

While VKC and AKC are different from SAC and PAC in certain clinical characteristics and the underlying disease process causing them, they share some common markers. Another related condition is giant papillary conjunctivitis (GPC), which is usually caused by wearing contact lenses or eye prosthetics. GPC shares significant similarities with VKC and AKC in terms of treatment and some aspects of the disease process, hence, they all fall under the umbrella of ‘eye allergies’. Although these conditions may initially be treated similarly, the outcomes and the risk of complications can differ.

What Causes Allergic Conjunctivitis?

Allergic conjunctivitis, or eye allergies, usually happen because of simple exposure to allergens, substances which cause an allergic reaction, on the surface of the eye.

Seasonal allergic conjunctivitis, also known as “hay fever eyes,” gets worse in the spring and summer seasons. The main causes are tree and grass pollens. The specific type of pollen causing allergies can differ based on where you live.

Perennial allergic conjunctivitis can happen any time of year, but it’s generally worse in the fall. This is mainly due to exposure to house dust mites, animal hair or fluff, and tiny particles of fungi. Compared to the seasonal type, perennial allergic conjunctivitis is less common and usually milder.

The exact cause of vernal keratoconjunctivitis, or VKC, is not well understood, but it is believed to be a result of both weather and exposure to allergens. Certain immune responses play a key role in developing VKC. VKC is categorised into 3 types based on symptoms:

Palpebral VKC: This primarily affects the inside of your upper eyelid. It is marked by significant involvement of the cornea, the clear front surface of the eye, due to its close contact with the inflamed conjunctiva, the thin covering of the eye.
Limbal VKC: This subtype is most common in individuals of black and Asian descent.
Mixed VKC: This subtype has a combination of features seen in both the palpebral and limbal types of VKC. It shows symptoms involving both the inside of your upper eyelid and the limbal area, the border between the cornea and the white of the eye.

The exact cause of atopic keratoconjunctivitis is not clear. However, it is believed to happen because of different factors, including exposure to allergens, atopic dermatitis (a skin condition which is present in over 90% of cases), and genetics.

The allergen exposure and subsequent reaction in giant papillary conjunctivitis, another type of eye inflammation, can be caused by foreign objects in the eye. These objects can carry allergens on their surface or cause damage to the eye structures which then allows allergens to sneak in. This condition can be associated with different foreign objects in the eyes such as contact lenses, eye implants, a type of glue called cyanoacrylate glue, and surgical stitches.

Risk Factors and Frequency for Allergic Conjunctivitis

Simple allergic conjunctivitis often doesn’t get enough attention. It’s difficult to count exactly how many people suffer from it, as many don’t seek medical help for their symptoms. Despite this, it’s believed to impact between 10% and 30% of the general population. Typically, it occurs in individuals under the age of 20, and is less common among older folks. While it can show itself independently, it’s often connected with other allergic conditions such as allergic rhinitis, dermatitis, and asthma.

Vernal Keratoconjunctivitis (VKC) is more commonly found in males, with roughly two to three males having the condition for every female. It mainly appears in kids between the ages of 5 and 10, often in those who have a history of atopy or asthma. By late adolescence, around 95% of patients get better, while the rest might develop atopic keratoconjunctivitis. VKC usually pops up in warm, dry areas like the Middle East, sub-Saharan Africa, and the Mediterranean region. It’s seen less frequently in temperate climates, where about 90% of patients have allergies, asthma, and eczema. Also, two-thirds have a history of atopy. VKC typically flares up in late spring and summer, but mild symptoms can remain all year round.

Atopic Keratoconjunctivitis (AKC) isn’t usually seen before someone reaches their teenage years and is most common between the ages of 30 and 50. It’s a rare disease that affects both eyes, and it’s usually seen in those who have a history of atopic dermatitis and asthma. Like with VKC, more males have the condition than females. About 5% of these patients once had VKC as a child. AKC is ongoing, often gets worse in winter and people with the condition are often sensitive to many different airborne environmental pathogens.

Giant Papillary Conjunctivitis (GPC) is mostly seen in teenagers and young adults due to its link with contact lens use. It’s most common in people who wear soft contact lenses with about 5% of these people being affected. GPC generally shows up 1 to 2 years after starting to wear soft contact lenses, although this can vary greatly if there are other foreign materials in the eyes. Certain things, like protein deposits or cell debris accumulating on contact lenses, ocular prostheses, sutures, and scleral buckles, can trigger GPC. Furthermore, irregular corneal surfaces or filtering blebs can also contribute to GPC. The chronic papillary reaction known as mucus fishing syndrome, which is caused by regular removal of mucus, can happen with various eye disorders. GPC can also coexist with AKC and VKC.

Signs and Symptoms of Allergic Conjunctivitis

Allergic conjunctivitis, an inflammation of the eye, often shows up along with seasonal allergies, particularly in people who already have known allergies or an atopy. It can occur repeatedly. Key symptoms include itchiness, and a redness of the conjunctiva region of the eye. The person’s history and physical exam findings may vary by type of allergic conjunctivitis.

There are several types of allergic conjunctivitis:

Simple Allergic Conjunctivitis

Simple allergic conjunctivitis is marked mainly by clear, watery discharge. It usually affects both eyes and might cause some crusting in the mornings. Pain and decrease in visual clarity are uncommon. Swollen eyelids and chemosis (swelling of the white part of the eye) are usual. Patients often have redness, watery discharge, and itching, often rubbing shoulders with sneezing, nasal discharge, and other symptoms of allergic rhinitis.

Vernal Keratoconjunctivitis (VKC)

Vernal Keratoconjunctivitis (VKC) symptoms typically flare up during spring and include thick mucus discharge, eye pain, excessive tearing, light sensitivity, and blurry vision. Patients often feel like there’s something in the eye. Giant papillae on the tarsal conjunctiva are commonly seen.
Unique features of Palpebral Vernal Keratoconjunctivitis include small, flat-topped lesions (less than 1 mm in size) which appear on the superior tarsal plate, along with mild redness of the conjunctiva and reduced mucus production.
Limbal Vernal Keratoconjunctivitis is characterized by gelatinous conjunctival papillae around the limbus (border) of the eye, and transient white cellular collections, known as Horner-Trantas dots. There might also be superficial scarring around the limbus, which is more severe in tropical regions.

Atopic Keratoconjunctivitis (AKC)

Atopic Keratoconjunctivitis (AKC) symptoms are year-round and include eye pain, blurry vision, light sensitivity, and a foreign body sensation in the eyes. AKC is similar to simple allergic conjunctivitis, with some additional chronic inflammation, corneal scarring, and new blood vessels in the cornea. There could also be changes to the eyelids and skin around the eyes.

Giant Papillary Conjunctivitis

Giant Papillary Conjunctivitis shows symptoms like simple allergic conjunctivitis that can get worse and continue for longer. Patients might have worse itching, a change in eye discharge from clear and watery to thick mucus. They could have contact lens intolerance, blurry vision, and feel as if there’s a foreign body in the eye after removing contact lenses.

Testing for Allergic Conjunctivitis

Doctors typically diagnose allergic conjunctivitis, or inflammation of the eye caused by allergies, by talking to the patient about their medical history and symptoms, and then examining their eyes. In cases where the doctor is worried about potential harm to the cornea, the outermost layer of the eye, they might use a dye called fluorescein to check for any scratches or damage.

In some cases, it might be helpful to figure out exactly what is causing the allergic reaction. This can be done with skin prick tests, where small amounts of common allergens are introduced to the skin with tiny pricks, or with serum allergy tests, which look for specific antibodies in your blood. Once the trigger is identified, you can take steps to avoid it and help manage your symptoms.

There are different types of allergic conjunctivitis, and the doctor can use different approaches to diagnose them. In simple allergic conjunctivitis, a tiny piece of the conjunctiva, the clear tissue covering the white part of your eye, might be removed for examination. This can help to identify white blood cells called eosinophils that show up in response to allergies. However, skin tests are rarely needed for this type of allergy.

In cases of vernal keratoconjunctivitis, a more severe form of eye allergy often seen in children and young adults, examining the conjunctiva can show a large number of eosinophils. On the other hand, in atopic keratoconjunctivitis, another severe form that tends to occur in people with a personal or family history of allergies, there are usually fewer eosinophils seen than in vernal keratoconjunctivitis.

Treatment Options for Allergic Conjunctivitis

Allergic conjunctivitis is discomfort or irritation in your eyes caused by allergies. If you have this condition, there are several steps that you can take to help alleviate your symptoms. Most importantly, avoid rubbing your eyes as this can worsen your symptoms, triggering a response in specific cells in your eyes which can cause an allergic reaction.

You should also use artificial tears and keep a cool compress on your eyes regularly. This can provide relief and reduce further irritation. Try to avoid anything that you know triggers your allergies and, if possible, remove your contact lenses.

In mild cases, over-the-counter allergy and eye drops could be helpful. While you can use them for a short period, it’s crucial to be aware that if you use some types of eye drops for long periods, your eyes could become rather red.

For more serious or persistent cases of allergic conjunctivitis, a variety of treatment options are available. Your doctor might suggest using a combination of allergy eye drops and drugs that help stabilize your reaction to allergens. While anti-inflammatory eye drops might help, they usually do not work as well as allergy eye drops.

For tough-to-treat cases, you might be given a short course of steroid eye drops, but this should be done under the supervision of a specialist. Also, in these stubborn cases, taking oral allergy medication and steroids might be limited, especially if the patient has more general symptoms rather than just eye symptoms.

The treatment you receive will typically depend on how severe your symptoms are. You may need to use over-the-counter eye drops for mild symptoms, whereas for more severe symptoms, you could be prescribed a combination of allergy medication and drugs to constrict the vessels in your eyes, such as antazoline and xylometazoline. Non-steroidal anti-inflammatory drugs can help reduce inflammation and relieve symptoms. You need to be careful when using steroid eye drops and limit their use to a brief period under specialist guidance.

If your symptoms are severe, you might need to take oral allergy medication such as diphenhydramine and loratadine. Loratadine, which causes less drowsiness, is usually preferred.

For people with resistant allergic conjunctivitis, a specialist might recommend topical corticosteroids. If this is not adequate, they may suggest using topical or systemic calcineurin inhibitors, a type of medication that stops your immune system from having an exaggerated reaction to the allergen.

At the core of managing allergic conjunctivitis, including serious forms like Vernal and Atopic Keratoconjunctivitis, is staying away from allergen exposure. In some cases, you might need to wear an eye patch, and a cornea specialist can help determine an appropriate treatment plan. Keeping good eyelid hygiene is essential to prevent and treat other conditions related to eyelashes.

Commercially-available moisturizing creams like E45 can help keep the skin around your eyes hydrated and comfortable. In cases where the outer layer of the eye (epithelium) is damaged, a special type of contact lens may be recommended to protect the cornea and help healing.

Your doctor might advise you to remove your contact lenses and use medication to stabilize your immune cell to relieve itching if you’re very uncomfortable. In some cases, you may need long-term use of such medication to manage and control your symptoms effectively. Also, you might need to use topical steroids if your condition is severe as they have strong anti-inflammatory effects.

If you have a tough to treat the form of allergic conjunctivitis, you might require a special type of solvent to help deal with mucus-related symptoms, topical antibiotics to prevent associated infections, or even oral immunosuppressant drugs. These help to control your immune system’s response and are often used in low doses for stubborn cases of allergic conjunctivitis.

Lastly, in the case of Giant Papillary Conjunctivitis, another form of eye inflammation, removing whatever is causing irritation (often a contact lens) is the first step. As with other forms of allergic conjunctivitis, you should follow general recommendations of not rubbing your eyes, using artificial tears, and keeping a cool compress over your eyes. Contact lenses may be replaced, adjusted, or cleaned more regularly if they’re the cause of the problem.

When trying to diagnose allergic conjunctivitis, doctors also consider several other conditions that present similar symptoms, including:

Viral conjunctivitis
Bacterial conjunctivitis
Molluscum conjunctivitis
Giant fornix syndrome
Adult chlamydial conjunctivitis
Trachoma
Neonatal conjunctivitis
Nonallergic eosinophilic conjunctivitis
Contact allergic blepharoconjunctivitis
Mucous membrane pemphigoid
Stevens-Johnson syndrome/Toxic epidermal necrolysis (Lyell syndrome)
Superior limbic keratoconjunctivitis
Ligneous conjunctivitis
Parinaud oculoglandular syndrome
Factitious conjunctivitis

It’s crucial for the physician to distinguish between these conditions and conduct necessary tests for accurate diagnosis.

What to expect with Allergic Conjunctivitis

In general, people with allergic conjunctivitis, which is inflammation of the eye due to allergies, can expect a good outcome. It’s rare that complications arise. However, there is a chance that symptoms might come back. In some cases, if the cornea (the clear front surface of the eye) has been damaged, this could lead to difficulties with vision.

Besides, it’s important to know that some medications used in treating allergic conjunctivitis may be linked to the development of cataracts, which is a clouding of the lens inside the eye that can affect vision.

Possible Complications When Diagnosed with Allergic Conjunctivitis

Allergic conjunctivitis, also known as pink eye, is usually not a serious health issue. It’s common and often harmless. However, sometimes there are complications, although they are rare. When complications do happen, they can be serious. Possible complications include:

Eye scarring in serious cases
Infective conjunctivitis, which can lead to infections spreading to other parts of the body
Scarring of the conjunctiva, the clear layer that covers the white part of your eye
Bacterial keratitis, an infection of the cornea, the clear front surface of the eye
Corneal neovascularization, when blood vessels grow into the cornea
Pannus, abnormal tissue growth over the cornea
Giant papillae, large, bumpy growths on the inside of your eyelids
Non-healing wounds on the cornea
Shield ulcer, a specific type of corneal ulcer
Steroid-induced glaucoma, when steroids used to treat inflammation cause high pressure in the eye
Dry eyes
Keratoconus, when the cornea becomes cone-shaped
Herpetic keratitis, a herpes virus infection of the cornea

Recovery from Allergic Conjunctivitis

Most of the time, surgery isn’t needed if you have allergic conjunctivitis, which is eye inflammation caused by an allergy. However, in some unique situations, surgery might be required. These may include severe cases where the clear tissue covering the front part of your eyes (cornea) is seriously affected, or if there are complications like shield ulcers. In such cases, different types of surgeries like grafting of a special membrane (amniotic), partial transplant of the cornea (lamellar keratopathy), or the application of a patch graft might be considered.

After the surgery, you will be given decreasing doses of steroid eye drops. This medication will help control post-surgery inflammation but it’s essential that you understand both their short and long-term side effects. You will need regular check-ups after the surgery. These visits will help your doctor ensure the healing is going well, evaluate how well the treatment is working, and deal with any flares-ups promptly.

Preventing Allergic Conjunctivitis

Prevention is key when dealing with allergic conjunctivitis, which is an inflammation of the eye caused by allergies. You can figure out what’s causing your allergies, or the specific allergen, through skin tests that are performed by specialists known as allergists. Knowing what triggers your allergies can help you make plans to avoid these triggers in the long run, and this can lower both how often and how harshly your allergy reactions occur.

It’s also critical for patients to understand their condition and treatment plan to effectively manage allergic conjunctivitis. Understanding what the disease is, the potential issues it can cause, and why it’s important to stick to the medication prescribed by your doctor, all play a crucial role in dealing with the condition successfully. As a patient, you should be informed about the different treatment options available and how to use these medications correctly.

Frequently asked questions

Allergic conjunctivitis is a common eye condition that can occur due to various reasons such as heredity, general inflammation, exposure to air pollution, an allergic reaction to an environment or substance, exposure to pollen, and interactions with pets. It can be broken down into three main types: acute, seasonal, and all-year-round.

It is believed to impact between 10% and 30% of the general population.

Signs and symptoms of Allergic Conjunctivitis include: - Itchiness of the eye - Redness of the conjunctiva region of the eye - Clear, watery discharge - Crusting in the mornings - Swollen eyelids and chemosis (swelling of the white part of the eye) - Redness, watery discharge, and itching - Sneezing and nasal discharge - Thick mucus discharge - Eye pain - Excessive tearing - Light sensitivity - Blurry vision - Feeling like there's something in the eye - Giant papillae on the tarsal conjunctiva - Small, flat-topped lesions on the superior tarsal plate (in Palpebral Vernal Keratoconjunctivitis) - Gelatinous conjunctival papillae around the limbus (in Limbal Vernal Keratoconjunctivitis) - Transient white cellular collections known as Horner-Trantas dots (in Limbal Vernal Keratoconjunctivitis) - Superficial scarring around the limbus (more severe in tropical regions, in Limbal Vernal Keratoconjunctivitis) - Chronic inflammation, corneal scarring, and new blood vessels in the cornea (in Atopic Keratoconjunctivitis) - Changes to the eyelids and skin around the eyes (in Atopic Keratoconjunctivitis) - Change in eye discharge from clear and watery to thick mucus (in Giant Papillary Conjunctivitis) - Contact lens intolerance - Feeling of a foreign body in the eye after removing contact lenses.

Allergic conjunctivitis is usually caused by exposure to allergens on the surface of the eye.

The doctor needs to rule out the following conditions when diagnosing Allergic Conjunctivitis: - Viral conjunctivitis - Bacterial conjunctivitis - Molluscum conjunctivitis - Giant fornix syndrome - Adult chlamydial conjunctivitis - Trachoma - Neonatal conjunctivitis - Nonallergic eosinophilic conjunctivitis - Contact allergic blepharoconjunctivitis - Mucous membrane pemphigoid - Stevens-Johnson syndrome/Toxic epidermal necrolysis (Lyell syndrome) - Superior limbic keratoconjunctivitis - Ligneous conjunctivitis - Parinaud oculoglandular syndrome - Factitious conjunctivitis

The types of tests that may be needed to diagnose Allergic Conjunctivitis include: 1. Medical history and symptom assessment: The doctor will talk to the patient about their medical history and symptoms to gather information. 2. Eye examination: The doctor will examine the eyes to look for signs of inflammation and damage. 3. Fluorescein dye test: If there is concern about potential harm to the cornea, the doctor may use a dye called fluorescein to check for any scratches or damage. 4. Skin prick tests: These tests involve introducing small amounts of common allergens to the skin with tiny pricks to determine the specific allergen causing the allergic reaction. 5. Serum allergy tests: These tests look for specific antibodies in the blood to identify the trigger of the allergic reaction. 6. Conjunctival biopsy: In some cases, a tiny piece of the conjunctiva may be removed for examination to identify white blood cells called eosinophils that show up in response to allergies. It is important to note that not all of these tests may be necessary for every case of Allergic Conjunctivitis, and the specific tests ordered will depend on the individual patient and their symptoms.

The treatment for Allergic Conjunctivitis depends on the severity of the symptoms. For mild cases, over-the-counter allergy and eye drops can be used, along with artificial tears and a cool compress. In more serious or persistent cases, a combination of allergy eye drops and drugs to stabilize the reaction to allergens may be recommended. In tough-to-treat cases, a short course of steroid eye drops may be prescribed under specialist supervision. Oral allergy medication and steroids may also be used, especially if there are more general symptoms. Topical corticosteroids and calcineurin inhibitors may be recommended for resistant cases. Avoiding allergen exposure is crucial, and additional treatments such as eye patches, moisturizing creams, and special contact lenses may be used. In the case of Giant Papillary Conjunctivitis, removing the irritant, such as a contact lens, is the first step.

When treating Allergic Conjunctivitis, there can be side effects, including: - Eye scarring in serious cases - Infective conjunctivitis, which can lead to infections spreading to other parts of the body - Scarring of the conjunctiva, the clear layer that covers the white part of your eye - Bacterial keratitis, an infection of the cornea, the clear front surface of the eye - Corneal neovascularization, when blood vessels grow into the cornea - Pannus, abnormal tissue growth over the cornea - Giant papillae, large, bumpy growths on the inside of your eyelids - Non-healing wounds on the cornea - Shield ulcer, a specific type of corneal ulcer - Steroid-induced glaucoma, when steroids used to treat inflammation cause high pressure in the eye - Dry eyes - Keratoconus, when the cornea becomes cone-shaped - Herpetic keratitis, a herpes virus infection of the cornea

The prognosis for allergic conjunctivitis is generally good, with rare complications and a low chance of symptoms returning. However, if the cornea has been damaged, there may be difficulties with vision. Additionally, some medications used to treat allergic conjunctivitis may be linked to the development of cataracts, which can affect vision.

An ophthalmologist or an allergist can diagnose and treat Allergic Conjunctivitis.

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