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Monday, October 22, 2018

When (if) spring actually arrives this year, it brings with it longer days, kids playing outdoors, the baseball season, open windows and light jackets. But if you are one of the millions of people who suffer from seasonal allergies, all the good feelings are for naught because you feel miserable for most of April and May.

As an ophthalmologist, I’m on the front lines in the treatment of allergies, since eyes are one of the primary organs affected, along with the nose, throat, lungs, GI tract and skin. Fortunately, there have been many advances over the years to both diagnose and treat allergies, whether they are seasonal or perennial and environmental.

Our body contains cells called mast cells, which are present in the bloodstream but tend to congregate near the barrier with the outside world—eyes, mouth, skin, lungs, nose and digestive tract. Mast cells are an important part of the immune system and contain many biological substances that mediate inflammation, including histamine. In response to an allergen, whether it is pollen in the spring or animal dander, the mast cells release the histamine and that results in the all-to-familiar symptoms of sneezing; runny nose; itchy, swollen and teary eyes; and skin rashes (hives) among others.

Treating allergies, specifically when related to the eyes, requires identifying the root cause and avoiding it if possible. Often people may think their allergies are seasonal, when in fact they might be allergic to mold or dust mites and have low grade symptoms year-round. We perform skin tests in the office to determine what each patient is allergic to.

The most common seasonal allergens vary by location. In the spring, it is most likely to be tree pollen, and in the fall, usually ragweed and grasses are the culprit.

The first line of defense in the fight against allergies is avoidance. This may take some work and may be impractical, but you won’t have an allergic reaction if you aren’t exposed in the first place. Don’t open windows. Buy an air purifier. Make sure you are recirculating the air on your car’s climate control so fresh air doesn’t come into the cabin. When you come in from outdoors, place your clothes in the laundry room and wash right away. Don’t air dry clothes outdoors. Don’t let pets sleep in your room. Even if you aren’t allergic to the pet, they carry in pollen from the outdoors.

In addition to avoidance, medications may be needed. From an eye perspective, I first recommend over-the-counter antihistamine eye drops. These medications counteract the effects of the histamine released by the mast cells. A second class of drops, available only by prescription, are the mast-cell stabilizers. They act one step earlier in the allergic cycle by preventing the mast cells from releasing the histamines in the first place. Finally, I will add a mild steroid eye drop for breakthrough symptoms. Steroid drops must be used with caution, because long-term use may lead to cataracts or glaucoma. I advise my patients to start the mast-cell stabilizer drops in mid-March, a few weeks before allergy season, since if we can prevent histamine release, we may be able to head off the allergies before they start.

Treating other symptoms may require oral antihistamines, most of which are now available over the counter. The choice depends on each patient and which medication works best for them. Steroid nasal sprays are also over the counter, and we can also prescribe montelukast orally to control inflammation.

Treating the eye symptoms can get tricky if you also have dry eyes. The symptoms of dry eye and allergies often overlap. One of the side effects of oral antihistamines is the drying out of the mucous membranes, including the eyes. So taking oral allergy medications if you have dry eye may worsen the dryness. That’s why it is important to have testing done to determine whether you have dry eyes, and what you might be allergic to. For patients with both conditions, I recommend staying away from the oral antihistamines if possible, and treating with drops, nasal sprays and oral medications that don’t contain antihistamines.

Seasonal ocular allergies are annoying, uncomfortable and can even make seeing or wearing contact lenses difficult this time of the year. The first step is identifying whether it is truly an allergy and if so, what you may be allergic to. Treatments, especially when started early in the season, can be effective. If not, Memorial Day isn’t too far away!

By Michael Farbowitz, MD