Eye Allergy Diagnosis
Eye allergies develop when the body’s immune system becomes sensitized and overreacts to something in the environment that typically causes no problem in most people. An allergic reaction can occur when that “something” (called an allergen) comes in contact with antibodies attached to the mast cells in your eyes; the cells respond by releasing histamine and other substances or chemicals that cause tiny blood vessels to leak and the eyes to become itchy, red and watery.
Eye allergies share symptoms with some diseases of the eye, making accurate diagnosis imperative. The symptoms of eye allergy can range from mildly annoying redness to inflammation severe enough to impair vision. If symptoms persist or over-the-counter remedies do not bring relief, see an GP or Optometrist who will review your medical history and symptoms and conduct tests that can reveal an eye allergy.
Those tests may include an examination with a microscope, which will show swollen blood vessels on the surface of the eye. In addition, your doctor may test for a certain type of white blood cell that shows up on areas of the eye affected by allergies. This involves gently scraping the conjunctiva (the inner lining of the eyelid) and seeing if those cells are found.
The primary types of eye allergy are seasonal or perennial allergic conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis, contact allergic conjunctivitis and giant papillary conjunctivitis.
Seasonal and perennial allergic conjunctivitis
Seasonal allergic conjunctivitis (SAC) is by far the most common type of eye allergy. Patients experience symptoms in spring, summer or fall, depending on the type of plant pollens in the air. Typical symptoms include:
- Clear, watery discharge
People with SAC may have chronic dark circles (known as allergic shiners) under their eyes. The eyelids may be puffy, and bright lights may be bothersome. SAC symptoms often accompany the runny nose, sneezing and nasal congestion associated with hay fever and other seasonal allergies. The itching may be so bothersome that patients rub their eyes frequently, making symptoms worse and potentially causing infection.
Perennial allergic conjunctivitis (PAC), as its name implies, occurs year-round. Symptoms are the same as with SAC, but tend to be milder. They are caused by reactions to dust mites, mold, pet dander or other household allergens, rather than pollen.
Vernal keratoconjunctivitis is a more serious eye allergy than SAC or PAC. While it can occur year-round, symptoms may worsen seasonally. It primarily occurs in boys and young men; about 75 percent of patients also have eczema or asthma. Symptoms include:
- Significant tearing and production of thick mucus
- The feeling of having something in the eye (foreign body sensation)
- Aversion to light (photophobia)
If left untreated, vernal keratoconjunctivitis can impair vision.
This type of allergy primarily affects older patients – mostly men with a history of allergic dermatitis. Symptoms of atopic keratoconjunctivitis can occur year-round and are similar to those of vernal keratoconjunctivitis:
- Severe itching
- Significant production of thick mucus that, after sleep, may cause the eyelids to stick together
If left untreated, atopic keratoconjunctivitis can result in scarring of the cornea and its delicate membrane.
Contact allergic conjunctivitis
This can result from irritation by contact lenses or by the proteins from tears that bind to the surface of the lens. Symptoms include:
- Mucous discharge
- Lens discomfort
Giant papillary conjunctivitis
Associated with wearing contact lenses, giant papillary conjunctivitis is a severe form of contact allergic conjunctivitis in which individual fluid sacs, or papules, form in the upper lining of the inner eyelid. Symptoms include:
- Mucous discharge
- Blurred vision
- Poor tolerance for wearing contact lenses
- Foreign body sensation
The first approach in managing seasonal or perennial forms of eye allergy should be to avoid the allergens that trigger your symptoms.
- Stay indoors as much as possible when pollen counts are at their peak, usually during the midmorning and early evening, and when wind is blowing pollens around.
- Avoid using window fans that can draw pollens and molds into the house.
- Wear glasses or sunglasses when outdoors to minimize the amount of pollen getting into your eyes.
- Try not to rub your eyes, which will irritate them and could make your condition worse.
- Keep windows closed, and use air conditioning in your car and home. Air conditioning units should be kept clean.
- Reduce exposure to dust mites, especially in the bedroom. Use “mite-proof” covers for pillows, comforters and duvets, and mattresses and box springs. Wash your bedding frequently, using hot water (at least 130 degrees Fahrenheit).
- To limit exposure to mold, keep the humidity in your home low (between 30 and 50 percent) and clean your bathrooms, kitchen and basement regularly. Use a dehumidifier, especially in the basement and in other damp, humid places, and empty and clean it often. If mold is visible, clean it with detergent and a 5 percent bleach solution.
- Clean floors with a damp rag or mop, rather than dry-dusting or sweeping.
Exposure to pets:
- Wash your hands immediately after petting any animals. Wash your clothes after visiting friends with pets.
- If you are allergic to a household pet, keep it out of your home as much as possible. If the pet must be inside, keep it out of the bedroom so you are not exposed to animal allergens while you sleep.
- Close the air ducts to your bedroom if you have forced-air or central heating or cooling. Replace carpeting with hardwood, tile or linoleum, all of which are easier to keep dander-free.
Many allergens that trigger eye allergies are airborne, so you can’t always avoid them. Discuss your symptoms with your GP or Optometrist to determine which treatment options are right for you.
Nonprescription (over-the-counter, or OTC) eyedrops and oral medications are commonly used for short-term relief of some symptoms. They may not relieve all symptoms, and prolonged use of some OTC eyedrops may actually cause your condition to worsen.
Prescription eyedrops and oral medications also are used to treat eye allergies. The prescription drops provide both short- and long-term targeted relief of eye allergy symptoms. Your GP or Optometrist can help determine which treatments are best for you.
Children can be treated with both OTC and prescription eyedrops and medications. Artificial tears are safe and can be used at any age. Some eyedrops, such as antihistamines and mast cell stabilizers, can be used in children 3 and older. Any treatment should be discussed with your child’s physician.
OTC eyedrops and medications
- Tear substitutes: Artificial tears can temporarily wash allergens from the eye and also moisten the eyes, which often become dry when red and irritated. These drops, which can be refrigerated to provide additional soothing and comfort, are safe and can be used as often as needed.
- Decongestants: OTC decongestant eyedrops reduce the redness associated with eye allergies by narrowing the blood vessels in the eye. (Note: These should not be used by anyone with glaucoma.) They are available with a decongestant only or with a decongestant and an OTC antihistamine, which provides additional relief from itching. Because the drops are weak, they must be used frequently (four to six times a day).Do not use these OTC decongestant eyedrops for more than two to three days. Prolonged use can create a “rebound effect” – increased swelling and redness that may last even after discontinuing the drops. You may be familiar with this if you have used decongestant nasal sprays for more than three days and your nose has become even more congested than it was before.
- Oral antihistamines: While oral antihistamines can be mildly effective in relieving the itching associated with eye allergies, they may cause dry eyes and potentially worsen eye allergy symptoms. Also, some OTC versions of these medications can cause side effects such as sedation, excitability, dizziness or disturbed coordination.
Prescription eyedrops and medications
- Antihistamine eyedrops: These can reduce the itching, redness and swelling associated with eye allergies. Although these drops provide quick relief, the effect may last only a few hours, and some must be used four times a day.
- Mast cell stabilizer eyedrops: These prevent the release of histamine and other substances that cause allergy symptoms. To prevent itching, the drops must be used before you’re exposed to an allergen.
- Antihistamine and mast cell stabilizer eyedrops: Some of the newest eyedrops have both an antihistamine and a mast cell stabilizer to treat and prevent eye allergies. They are used twice a day and provide quick, long-lasting relief of itching, redness, tearing and burning.
- NSAID eyedrops: Nonsteroidal anti-inflammatory drugs (NSAIDs) are available in eyedrops to relieve itching. These drops may cause stinging or burning when applied and may need to be used four times a day.
- Corticosteroid eyedrops: These can help treat chronic, severe eye allergy symptoms such as itching, redness and swelling. Long-term treatment with steroids (more than two weeks) should be done only under the supervision of an ophthalmologist; side effects of continued use include a risk of infection, glaucoma and cataracts.
- Nonsedating oral antihistamines: Prescription antihistamines can be mildly effective in relieving the itching associated with eye allergies. While they do not have the same sedating side effects as OTC antihistamines, these medications can cause dry eyes and worsen symptoms.
- Allergy shots (immunotherapy): Allergy shots work by improving an individual’s tolerance to the substance that causes an allergic reaction. Tiny amounts of the allergen are injected with gradually increasing doses over time. The treatment takes several months to achieve maximum results, and you may still be required to use medications to alleviate symptoms.
If you would like to learn more or book an appointment at Labuschagne & Alberts Optometrists simply call: 018 468 8903 or come make a visit at 10 Rockwill Square Corner William & Austin Streets, Wilkoppies.