Allergic conjunctivitis is a common eye condition that occurs when the thin, clear membrane covering the white part of the eye and inner eyelid (conjunctiva) becomes inflamed due to an allergic reaction, causing itching, burning sensation, and irritation. To help you understand and manage this condition better, this blog covers all you need to know about allergic conjunctivitis, including its causes, symptoms and treatment options. Let’s start with the basics.
What is Allergic Conjunctivitis?
Allergic conjunctivitis happens when the eyes react to certain substances, called allergens, such as pollen, dust, pet dander, or mold. When these allergens touch the surface of the eye, the body releases a chemical called histamines to fight them off. This reaction causes the eyes to become red, itchy, and watery.
There are two main types of allergic conjunctivitis:
- Seasonal allergic conjunctivitis: This usually appears during spring and fall when pollen levels are high. It affects people sensitive to tree, grass, or weed pollens.
- Perennial allergic conjunctivitis: This can happen all year round and is often triggered by indoor allergens like dust mites, pet hair, or mold.
Allergic conjunctivitis is part of a broader allergic response, so it is often seen alongside other allergy symptoms such as an itchy or runny nose and sneezing. Unlike infections, it is not contagious and usually affects both eyes at the same time, since both are exposed to the same allergens.
What Causes Allergic Conjunctivitis?
Allergic conjunctivitis is caused by common everyday substances that are harmless to most people but trigger reactions in those with allergies. Common triggers for allergic conjunctivitis include:
- Pollen: Tiny particles released by trees, grasses, and weeds can easily enter the eyes through the air. In sensitive individuals, pollen triggers the immune system, causing the eyes to become red, itchy, and watery. Even short exposure during high pollen days can provoke noticeable irritation.
- Dust mites: These microscopic creatures thrive in household dust, bedding, carpets, and upholstered furniture. Proteins from their bodies and droppings can act as allergens, irritating the eyes when they come into contact with the conjunctiva.
- Pet dander: Proteins found in pet hair, skin flakes, saliva, and urine can stick to surfaces and float in the air. Contact with these proteins can trigger allergic reactions, particularly in people sensitive to cats, dogs, or other pets.
- Mould spores: Mould releases spores that can become airborne indoors or outdoors. Inhaling or having the spores come into contact with the eyes can trigger allergic reactions, particularly in damp, poorly ventilated spaces.
- Environmental irritants: Smoke, chemical fumes, strong perfumes, and air pollution do not always cause allergies but can aggravate the eyes and make them more sensitive to allergens, leading to increased inflammation and discomfort.
- Eye care or cosmetic products: Sometimes, preservatives or chemicals in eye drops, contact lens solutions, or makeup can trigger irritation similar to allergic conjunctivitis, especially in sensitive individuals.
What Symptoms are Associated with Allergic Conjunctivitis?
Allergic conjunctivitis causes noticeable irritation in the eyes due to the immune system’s reaction to allergens. The symptoms include:
- Itchy eyes: Constant itching is often the most bothersome symptom, making it hard to focus or relax.
- Redness: The eyes may appear pink or bloodshot due to inflammation of the conjunctiva.
- Excessive tearing: The eyes may water frequently as the body tries to flush out the allergens.
- Swollen eyelids: In some cases, the eyelids may puff up or feel tender.
- Burning or stinging sensation: Many people experience a mild burning feeling that adds to the discomfort.
- Sensitivity to light: The eyes may feel more sensitive to bright light, causing squinting or discomfort outdoors.
- Discharge: Usually watery, unlike the thick or sticky discharge seen in infections.
Symptoms often appear in both eyes at the same time, since both are usually exposed to the same allergens. They may also flare up seasonally for those sensitive to pollen or persist throughout the year with indoor allergens such as dust or pet dander.
How is Allergic Conjunctivitis Treated?
Treatment for allergic conjunctivitis focuses on relieving discomfort, reducing inflammation, and controlling the allergic response in the eyes. The choice of treatment depends on the severity of symptoms and frequency of flare-ups:
- Antihistamine Eye Drops: Antihistamine eye drops are often the first-line treatment for allergic conjunctivitis. They work by blocking histamine, the chemical responsible for itching, redness, and swelling in the eyes. These drops provide fast-acting relief, often within minutes, making them suitable for acute flare-ups. Some antihistamine drops also include stabilisers that prevent further allergic reactions, helping reduce the frequency of symptoms during allergy-prone seasons.
- Mast Cell Stabilisers: Mast cell stabilisers are used to prevent the eyes from reacting to allergens. Unlike antihistamines, which provide immediate relief, these drops work over time by inhibiting the release of histamine and other inflammatory chemicals from immune cells in the eyes. Regular use of mast cell stabilisers can reduce the severity and recurrence of allergic conjunctivitis, especially in people with persistent or seasonal allergies.
- Anti-inflammatory Eye Drops: For cases with moderate to severe inflammation, ophthalmologists may prescribe non-steroidal anti-inflammatory eye drops (NSAID drops). These drops help reduce redness, swelling, and irritation. In more serious or persistent cases, steroid eye drops may be prescribed, but they are used cautiously due to potential side effects such as increased eye pressure or risk of infection.
- Lubricating or Artificial Tears: Artificial tears help flush out allergens from the surface of the eye and keep the eyes moist, which can reduce irritation. They provide temporary relief from itching, burning, and watering and can be used safely alongside other eye drops for enhanced comfort.
- Cold Compresses: Applying a cold compress to closed eyelids can immediately reduce swelling, redness, and discomfort. While not a medication, it is a safe and effective supportive treatment that can be used during flare-ups to soothe irritated eyes.
- Combination Therapies: Sometimes, a combination of treatments is recommended. For example, a patient may use antihistamine drops for quick relief, mast cell stabilisers for long-term control, and artificial tears or cold compresses for additional comfort.
With the right treatment, most people can effectively manage allergic conjunctivitis, reduce flare-ups, and improve comfort in daily activities.
How Can Allergic Conjunctivitis be Prevented?
The best way to prevent allergic conjunctivitis is to avoid the things that cause it. The primary goal in managing allergic conjunctivitis is to avoid exposure to the allergen that triggers the allergic response. Here are simple ways to do this:
Reduce Exposure to Outdoor Allergens
- Limit outdoor activities during peak pollen times: Pollen counts are usually highest in the early morning and on dry, windy days. Staying indoors at these times can help reduce eye irritation.
- Keep windows closed: In both homes and vehicles, keeping windows shut prevents pollen and dust from entering. Using air conditioning with clean filters is a better option.
- Protect eyes when outdoors: Sunglasses or wraparound glasses create a barrier against pollen, dust, and wind that may carry allergens.
Minimise Indoor Allergens
- Control dust mites: Use dust-proof pillow and mattress covers, wash bedding in hot water weekly, and avoid heavy drapes or carpets that collect dust.
- Reduce pet dander: Keep pets out of bedrooms and bathe them regularly to lower the spread of dander.
- Prevent mould growth: Keep bathrooms, kitchens, and other damp areas dry and well-ventilated. Using a dehumidifier may help in humid climates.
- Regular cleaning: Vacuum frequently with a HEPA filter vacuum cleaner and mop floors to remove fine particles.
Maintain Eye Hygiene
- Avoid rubbing the eyes: Rubbing can release more histamine and worsen redness and itching.
- Rinse eyes when exposed to allergens: Washing with clean water or using preservative-free artificial tears can flush away irritants.
- Care with cosmetics: Use hypoallergenic makeup and remove all traces before sleeping to avoid buildup that may irritate the eyes.
Manage Environmental Irritants
- Avoid smoke and fumes: Cigarette smoke, strong perfumes, and chemical fumes can worsen eye irritation.
- Improve air quality indoors: Air purifiers with HEPA filters can reduce allergens such as dust and pollen in the living environment.
Consult Today
Sometimes what feels like simple allergies could be something else entirely, or you might need a more targeted treatment approach than over-the-counter drops can provide. If you’ve been struggling with persistent eye irritation, redness, or that constant urge to rub your eyes, it’s time to get some medical help. The ophthalmologists at Max Hospital specialise in diagnosing and treating all types of eye conditions, including allergic conjunctivitis. They can help you identify your specific triggers, create a personalized prevention plan, and recommend the most effective treatments for your case.
Frequently Asked Questions
1. Can allergic conjunctivitis affect vision permanently?
No, allergic conjunctivitis does not cause permanent damage to vision. The symptoms, though uncomfortable, usually affect the surface of the eyes without harming deeper structures. Vision may feel blurry during flare-ups, but it clears once the irritation settles.
2. How long does allergic conjunctivitis usually last?
That depends on the trigger. Seasonal allergic conjunctivitis may last for a few weeks during pollen season, whereas perennial allergic conjunctivitis can linger throughout the year if indoor allergens like dust or pet dander are present.
3. Is allergic conjunctivitis more common in children or adults?
It can affect both, but children and young adults often experience it more. This is because they are usually more sensitive to environmental allergens.
4. Can contact lens wearers develop allergic conjunctivitis?
Yes, contact lens wearers may be more prone to eye irritation and allergic reactions. Allergens can stick to the lens surface, worsening symptoms. Switching to daily disposable lenses or limiting lens use during allergy season may help.
5. How do I know if my eye redness is due to allergy or an infection?
Allergic conjunctivitis usually causes itching, watery discharge, and affects both eyes. Infections often cause thick, yellow or green discharge, pain, and sometimes affect one eye first. An ophthalmologist can confirm the cause with an examination.
6. Does allergic conjunctivitis get worse at certain times of the day?
Yes, many people notice their symptoms are worse in the morning due to allergens collecting overnight, or when spending time outdoors during peak pollen hours.
7. Can untreated allergic conjunctivitis lead to other eye problems?
In most cases, it doesn’t cause serious complications. However, constant rubbing of the eyes can worsen irritation and, over time, may affect the eye surface. That’s why proper treatment is important.
8. Are there any tests to confirm allergic conjunctivitis?
Diagnosis is usually based on symptoms and eye examination. In some cases, allergy testing may be suggested to identify specific triggers.
9. Can allergic conjunctivitis occur only in one eye?
It usually affects both eyes since allergens come in contact with both. If only one eye is affected, it’s worth checking with an eye specialist to rule out other causes.
10. Does diet or hydration have any role in reducing flare-ups?
Diet is not a direct cause, but staying hydrated and eating foods rich in vitamins A and C can support eye health. A strong immune system may also help reduce the intensity of allergic reactions.
