Spring Eye Allergies

Spring has sprung and May and June in this part of the country means mowing (twice a week for some!), baseball, softball, golf and lake activities. The fescue grows tall and fast and the grass pollen levels usually peak around Memorial Day bringing much suffering and misery to many who spend time outdoors. Warmer temperatures and an early spring has resulted in high airborne levels of grass pollen in Missouri since early April.



The eyes are especially vulnerable to airborne allergens like grass pollen. Symptoms of eye allergies, or allergic conjunctivitis, include watery, itchy, red, sore, swollen and stinging of the eyes. Itching of the eyes is the most important symptom of allergic conjunctivitis. Without itching, it is much less likely that a person is suffering from allergies of the eyes. Both eyes are usually affected.



Seasonal allergic conjunctivitis (SAC) is the most common form of eye allergy, with grass and ragweed pollens being the most important seasonal triggers. Perennial or year round, allergic conjunctivitis (PAC) is also very common, with animal dander, feathers and dust mites being the most important triggers.





People with SAC usually note the onset of symptoms during the spring and fall, and frequently note nasal problems as well. Symptoms include itchy eyes, burning of the eyes and eye watering. In some cases, people notice sensitivity to the light and blurred vision. The eyes are usually red, and the eyelids may become swollen. When the inside of the eyelid (the conjunctiva) is also swollen, the eyes may have a watery, gelatinous-like appearance - called "chemosis". PAC typically occurs year-round, although many people notice some seasonal flares to their symptoms. The severity of PAC is less than that of SAC, and PAC is much more likely to be associated with perennial allergic rhinitis.





The diagnosis of allergic conjunctivitis is made with a history of symptoms suggestive of eye allergies, an examination by a healthcare professional with findings consistent with conjunctivitis, and allergy testing showing seasonal or perennial allergies. A response to typical medications is helpful in the ultimate diagnosis of allergic eye disease, and failure to respond to medications may lead to a search for a different diagnosis.



If avoidance of allergic triggers fails to prevent symptoms of allergic conjunctivitis, some people notice mild benefit from cold compresses on the eyes, and eyewashes with tear substitutes. However, medications may be necessary to treat the symptoms. Medications for allergic conjunctivitis include oral antihistamines and eye drops.



Many people with allergic eye disease will receive benefit from oral antihistamines, such as over-the-counter loratadine (Claritin®/Alavert®, generic forms), and cetirizine (Zyrtec®). Fexofenadine (Allegra® and generic forms, Levocetirizine (Xyzal®) and desloratadine (Clarinex®). Older, first-generation anti-histamines (such as Benadryl®) are also helpful, but are generally considered too sedating for routine use.


Over-the-counter eye drops. Medicated eye drops are available in over-the-counter and prescription forms. Over-the-counter eye drops for allergic conjunctivitis include decongestant (Visine®, Naphcon®, generic forms of naphazoline), and decongestant/anti-histamine combinations (Visine-A®, Naphcon-A®, generic forms of naphazoline/pheniramine).


Decongestant eye drops (with or without anti-histamines) should only be used for short periods of time, as overuse can lead to conjunctivitis medicamentosa (characterized as rebound eye redness/congestion and dependence on the eye drops). These eye drops should not be used by people with glaucoma, and used with caution by people with heart or blood pressure problems.


The Food and Drug Administration recently approved ketotifen eye drops(Zaditor®) for over-the-counter use. Unlike decongestant eye drops, ketotifen would not be expected to result in conjunctivitis medicamentosa with long-term use.


There are several prescription allergy eye drops available if needed. See your physician or eye care professional if symptoms are persistent or more than a minor nuisance.

Cottonwood allergy

"Cottonwood allergy" is a very common complaint and reason people visit an allergy specialist. However, this is usually a case of mistaken identity. Although cottonwood trees produce pollen that can cause significant allergy problems, cottonwood and most other trees release their pollen in the early spring. Cottonwood pollen is invisible. Cottonwoods also produce "tufts" or seeds that float through the air on warm summer days. When people experience allergy symptoms on these days they associate their symptoms with the floating tufts or seeds from the cottonwood tree. These tufts are not capable of causing significant respiratory allergy. Grass pollen, which is also invisible, peaks in the late spring and early summer coincident with the appearance of the cottonwood tufts. Grass pollen is the likely offender when "cottonwood allergy" is suspected.

Do hypoallergenic pets exist? The primary causes of allergic reactions to dogs and cats is not the hair or fur, but dander or old skin scales which are constantly shed into the environment. These allergens are small proteins that allergy sufferers seldom realize are circulating in the air, in carpetting, clinging to furniture, draperies and wall coverings. If a dog or cat has been in the home for a long time, its dander will be present in the entire house. Dander occurs in the epidermis, or the outer layer of skin. The epidermis of dogs and cats is thin, only a few cells thick. The cells turnover about every 21 days, the outer cells die and flake off as dander. In some breeds that are prone to dry and oily seborrhea, the epidermal turnover is 3 to 4 days. Dander is easily airborne and can be present in high enough levels to cause symptoms even if a pet is not present. Significant levels can be found in classrooms, even if a pet has never been in the room. Dander can persist in the environment even months after the pet has been removed. Up to 10% of the general population and 40% of allergic individuals react to cats and dogs. Allergy to cats is twice as common as allergy to dogs. In most areas of the country approximately 50% of homes will have a dog or cat living indoors. Many of the homes where there is no pet living inside still contain enough dander to cause an allergic reaction. There are 90 million cats and 75 million dogs in the US. 17% of cat owners and 5% of dog owners are sensitized to their pets' dander. Cat dander is generally more likely to cause allergies than dog dander. The vast majority of pet owners keep their pets despite being advised by their allergists to keep the pets outside of the house. Many let the animals sleep on their bed. Pet owners ask about available measures to reduce the accumulation of dander in the house. Some measures to reduce dander include moving the pet outside, restricting the pet to a certain are a in the home, frequent bathing of the pet, house cleaning, using a vacuum cleaner with a HEPA filter, or having multiple HEPA air filtration devices. No avoidance measure can compare with removal of the pet. Pet allergies are on the rise. More people are keeping indoor pets. Pet allergy can cause significant allergy problems, including asthma and eczema. Despite claims about certain breeds by people in the $50 billion pet industry, NO SCIENTIFIC EVIDENCE HAS BEEN PUBLISHED to support the claims of "hypoallergenic" dogs or cats. On the contrary, there are several good studies refuting this notion. When a danderless cat is developed, I will reconsider and blog all about it. Wait a minute...isn't that called an iguana?

MEOW???