Allergic conjunctivitis describes allergy symptoms of the eyes, or "eye allergies".
Conjunctivitis refers to inflammation of the conjunctiva, the pink, moist tissue that lines the inside of the eyelids.
Allergic conjunctivitis is commonly triggered by pollen, mold spores, pet dander, and/or dust mites, the same substances (allergens) that can trigger an itchy and runny nose.
Conjunctivitis can also be caused by irritation from dust or smoke, or by an infection. Conjunctivitis that is due to an infection by bacteria or virus is commonly referred to as "pink eye". Viral conjunctivitis and bacterial conjunctivitis can spread easily from person to person, but allergic conjunctivitis is not contagious.
It is important to determine whether the eye symptoms are caused by allergies, infection, or some other condition because the optimal treatment differs depending on the cause.
What causes allergic conjunctivitis?
- When your eyes are exposed to substances to which you are allergic (allergens), histamine is released and the blood vessels in the conjunctiva become swollen. Reddening of the eyes develops quickly and is accompanied by itching and tearing.
- Allergies tend to run in families, but not in a predictable manner.
What are the symptoms of allergic conjunctivitis?
Eye symptoms which may be due to allergies include:
- Itchy eyes
- Redness in the white of the eye or inner eyelid
- Increased amount of tears
- A crusty discharge that forms during the night
- Swelling of the eyelid
Keep in mind that rubbing the eyes releases more histamine and can worsen allergy symptoms.
How is allergic conjunctivities treated?
Allergic conjunctivitis may disappear completely, either when the allergy is treated with antihistamines, or when the allergen is removed. For instance, people with allergies to grass pollen may notice their eyes becoming less red and itchy after the end of grass pollen season.
Your healthcare provider may recommend the following medications:
- Ocular Decongestants (Naphcon-A®, Opcon-A®, Vasocon-A®): These eye drops reduce redness by constricting small blood vessels in the eye. They are not recommended for long-term use. Using these drops for more than a few days can worsen symptoms.
- Ocular Antihistamines (Elestat®, Patanol®, Zaditor®): These eye drops reduce redness, swelling, and itching by blocking histamine, the chemical that causes many allergy symptoms. Some brands are available over the counter and others require a prescription.
- Ocular NSAIDs (Acular®): These aspirin-like drugs reduce itch.
- Ocular Steroids (Lotemax®, Alrex®): When other medicines fail, corticosteroid eye drops can help to relieve symptoms. Steroids are used with the supervision of a doctor since they can cause negative side affects if not used carefully. These drops can also increase the risk of cataracts, clouding of the lens that can cause long-term damage and impair your vision.
- Mast cell stabilizers (Alomide®, cromolyn®, Alamast®, Alocril®). These eye drops can prevent the outbreak of allergy symptoms before they begin and can be used for weeks or months without any significant side effects. They are good for those afflicted with eye allergies who can anticipate exposure to known allergens, such as before pollen season or prior to exposure to a pet. They are not effective at controlling immediate symptoms.
- Oral Antihistamines and Nasal Sprays: Antihistamines and/or nasal sprays may be combined with eye drops to help control nasal allergy symptoms.
- Immunotherapy: Allergy shots can be effective at controlling eye allergy symptoms over the long-term.
What can I do to relieve symptoms?
The best defense against allergic conjunctivitis is to simply avoid contact with allergens that trigger your allergies, if possible. Other tips include:
- Don't touch or rub your eye(s).
- Use a cold compress on your eyes.
- Wash hands often with soap and water.
- Choose glasses instead of contact lenses during allergy season.
- Try nonprescription drops to help relieve itching and burning.
- Wash your bed linens and pillowcases with hot water and detergent to reduce allergens.
- Avoid wearing eye makeup.