Brian Hansel, O.D.
Most people associate sneezing, runny nose, coughing, and hives as a reaction to some types of allergens. Surprisingly, to these sufferers when their eyes are involved, they are often experiencing allergic conjunctivitis. Allergic conjunctivitis is an inflammation (-itis) of the mucosal membrane called the conjunctiva. This surrounds the white part of the eye called the sclera and covers the pink eyelid part of the eye called the palpebra. An allergic reaction can be caused by a hypersensitivity to environmental factors. Beyond the inconvenience of having watery itchy eyes that can cause dark circles, this condition is usually self-limited to the season or to the irritant. Vision is usually only mildly affected with watery eyes, but overall remains intact.
So what causes allergic conjunctivitis? Considering other parts of the body like the nose and throat, the immune system becomes hyper-vigilant and produces antibodies to counter a perceived threat. The antibody binds to an antigen, connects to an immune cell, which then in turn releases histamine and other chemicals that cause the itch, redness, and mucus secretion associated with allergies. Seasonally this occurs with hay fever, tree pollens, and molds. It can also work full-time throughout the year for those who are allergic to dust mites and pet dander.
How do we treat it? Often the best way to treat allergic conjunctivitis is avoidance of the allergens such as dust mites, molds, and pet dander. If symptoms persist, an oral antihistamine such as Zyrtec, Allegra, or Claritin usually work well. As always, be sure to talk to your primary care physician before starting any medication. Benadryl can be used as well, seeing that it is also an antihistamine drug, however, it is known to cause drowsiness. Artificial tears can help wash the offending allergens out of the eye decreasing inflammation and increasing comfort. Alaway and Zaditor drops are antihistamine mast cell stabilizers and are very effective in treating the symptoms of itching and redness. Once daily prescription drops Pataday and Lastacaft, are now available over the counter.
If you wear contact lenses, the FDA recently approved a daily disposable contact lens indicated for the prevention of ocular itch due to allergic conjunctivitis. They are indicated for vision correction in patients who do not have red eyes, who are suitable for contact lens wear and who do not have more than 1.00 D of astigmatism. The lenses are still being rolled out and may be available here in the fall.
The good news is that allergies are isolated to the individuals who suffer from them. When in doubt, it is wise to have a second look by your eye doctor especially if the eyes remain red and your symptoms do not improve with over the counter treatments to ensure no other medical conditions exist.
BIO: Dr. Hansel is an optometrist with Eye Surgeons Associates and practices at our Bettendorf, IA clinic. His areas of clinical interest include family optometric practice, ocular surface disease management, glaucoma, medical co-management and contact lenses.
The material contained in this article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health care provider.