Allergic Conjunctivitis Eyes - Managing Your Allergies: Allergies

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Allergic conjunctivitis (eyes)

Allergies of the eye affect about 20% of Americans each year and are on the rise. The same inhaled airborne allergens — pollens, animal dander, dust mites, and mold — that trigger allergic rhinitis can lead to seasonal or year-round allergic conjunctivitis (inflammation of the conjunctiva, the lining of the eye). In this way, allergic conjunctivitis is a close cousin of allergic rhinitis, which makes sense because they are both IgE-mediated allergic responses. About 50% of allergic conjunctivitis sufferers, who tend to be young adults, have other allergic diseases or have a family history of allergies. The symptoms, which can be seasonal or year-round (about 80% of eye allergies are seasonal), are itchy and red eyes, tearing, edema (swelling) of the conjunctiva or eyelid, and a mucous discharge. Contact dermatitis can also affect the eyelid or the conjunctiva, but in that case the allergens are typically cosmetics, eye medications (such as topical neomycin), and preservatives (such as thimerosal). Although it can be uncomfortable, you can rest assured that uncomplicated allergic conjunctivitis is not a threat to vision.

A more serious condition, however, is atopic keratoconjunctivitis, which occurs in as many as 25% of atopic dermatitis sufferers and can result in loss of sight. Atopic keratoconjunctivitis may start in the teen years, but it most often appears between ages 30 and 50. People with atopic keratoconjunctivitis complain of itching, burning eyes, and blurred vision. Often they have a mucous discharge and are sensitive to sunlight. Vernal keratoconjunctivitis is another serious but rare eye disease that is sometimes related to allergies. The disorder appears mainly in young boys who can outgrow the condition when they reach puberty. The disorder is rare in the colder northern climes, preferring warmer, subtropical climates. If you think you have allergic conjunctivitis that isn’t responding to treatment, see your doctor or ophthalmologist.

Diagnosing allergic conjunctivitis

Seasonal and year-round allergic conjunctivitis usually can be confirmed by your doctor based on your symptoms. Testing is not usually needed to diagnose the condition, but skin testing may help identify the allergens. If your symptoms don’t quickly respond to treatment, see your doctor in case you have a more serious eye condition.

Treating allergic conjunctivitis

Avoidance is the name of the game. If you are allergic to cats, avoid them. If you pet a cat, don’t touch your eyes, and be sure to wash your hands immediately afterward. Or if pollen is your nemesis, keep your windows closed and air conditioning going in pollen season. Also, don’t rub your eyes, because rubbing causes mast cells to release their histamine and other inflammatory chemicals, which worsens symptoms. Because allergic conjunctivitis can give you dry eyes, and taking the older first-generation oral antihistamines can aggravate that symptom, use artificial tears frequently for relief and because they can dilute allergens in the eye. Artificial tears are available without prescription.

As with other IgE-mediated allergic responses, allergic conjunctivitis can be treated with the newer generation of antihistamines, mast cell stabilizers, and corticosteroids. For symptoms that persist despite oral antihistamines, switch to regular use of a mast cell stabilizer (nedocromil) or an antihistamine eye drop. Eye drops also work faster than oral medications when you are having an acute attack. Several brands of eye drops, such as Opcon-A, Naphcon A, Vasocon-A, and Visine-A, are available over the counter. Your pharmacist will be able to advise you. Some of the newer antihistamines — olopatadine (Patanol), ketotifen (Zaditor) — may also act as mast cell stabilizers, have anti-inflammatory properties, or both. Because of the potential for harmful side effects, use topical corticosteroids only under the guidance of your ophthalmologist. Left to your own resources, you risk glaucoma, cataracts, or a devastating viral infection that can lead to blindness.

Last updated:	August 21, 2006
Reviewed By:	Faculty of Harvard Medical School