IN SPRING, we get to see the world come alive again. It’s a time for new possibilities, where anything can happen, for example, a fresh start for your favorite baseball team and a path to the World Series. But, with spring training, comes allergy season.
“Worldwide sensitization rates to one or more common allergens among school children are currently approaching 40% to 50%,” according to the American Academy of Allergy, Asthma & Immunology. Some other data suggest that ocular allergies in the adult population worldwide are at 15% to 20%.
As primary eye care providers, we are on the forefront of diagnosing and managing these patients. Here, I discuss how to diagnose and manage allergic conjunctivitis.
View allergy — or allergic conjunctivitis — as a diagnosis of exclusion because many of the allergy symptoms patients experience, such as itching and burning, can be similar to dry eye disease (DED) or, possibly, an infection. Rule out those conditions before instituting therapy for allergies. (See “Triggering the Cascade” p.21 and “Ocular Allergy vs. Dry Eye Disease” on p.19.)
Next, determine the suspected allergen or allergens. Gathering a comprehensive case history is a must to achieve this. Ask the patient when symptoms began, how long they last, if symptoms are progressing and whether they’re worse while outdoors vs. indoors. Also, inquire about other modifying factors, such as whether symptoms increase when at school/work but are better when at home; itching is not as severe when visiting family in Florida vs. at home in South Dakota, etc., and the quality or severity of symptoms. This provides the necessary background information needed to address patient complaints.
Now, test patients for allergies so you can address the root causes. I use the Doctor’s Allergy Formula system (Bausch + Lomb) that tests for 60 specific ocular allergies, both indoor and outdoor. (Outdoor allergens are unique to the region of the U.S. in which you live.) The scratch test takes three minutes to administer on the patient’s arm, and results are determined in 15 minutes. A caveat: Patients’ systems need to be clear of any antihistamines and some tricyclic antidepressants, such as amitriptyline, for about five to seven days before administering the test, or you won’t get a true result. This specific test is typically covered by most major medical insurances, according to the Bausch + Lomb website.
The first treatment solution in allergy management is avoidance. You can’t get resolution for someone who is allergic to cats if he or she sleeps with a cat every night, for example. Once you find out what the patient is allergic to, try to incorporate avoidance techniques, such as not sleeping with the cat.
Ocular Allergy Drugs
- Antihistamine/mast cell stabilizer:
Alaway (Bausch + Lomb)
Bepreve (Bausch + Lomb)
- Mast cell stabilizers:
Crolom (Bausch + Lomb)
Alrex (Bausch + Lomb)
Lotemax (Bausch + Lomb)
Pred Forte (Allergan)
Ocular allergy pellets (Natural Ophthalmics)
Allergy desensitization eye drops (Natural Ophthalmics)
Allergy eye relief (Similasan)
Provide the patient with a printout of all the allergens he or she suffers from, and suggest modifying his or her environment to provide allergy relief. For example, indoor modifications might include having one’s home duct work cleaned or eliminating carpets and plants in the household. Outdoor changes might include clearing trees and plants.
If it is not possible to avoid the antigens or modify your environment, incorporate pharmacological therapy. I start with a prescription combination antihistamine/mast cell stabilizer drop. Some of these offer the advantage of once-daily dosing. A topical antihistamine is an option, as well. I also institute an oral antihistamine to provide further symptom relief. This combination of topical and systemic medications addresses 75% of the cases of seasonal allergic conjunctivitis I see. Antihistamines can provide acute relief of redness and itching, while mast cell stabilizers can decrease or eliminate symptoms of an allergic attack when taken in advance (several weeks or more prior to allergy season).
Ocular Allergy vs. Dry Eye Disease
- One signature of ocular allergy vs. dry eye disease is the mild time delay from interaction with allergen to symptoms, including puffy eyelids, red eyes and tearing.
- Allergic issues are typically confined to the bulbar and tarsal conjunctiva.
- Allergies may have concomitant systemic manifestations, including rhinitis, dermatitis and respiratory maladies.
For more, read “Is it Allergy or Dry Eye?” in Aug. 2012’s OM (tinyurl.com/OMallergy ).
If the patient needs further improvement, I prescribe a topical steroid to be used two to four times daily. Antihistamines and mast cell stabilizers only address one aspect of the allergy cascade, but not the inflammatory cytokines, so steroids are sometimes needed. (See “Ocular Allergy Drugs,” for a list of pharmacological options, p.17.)
My last resort is to institute immunotherapy. Immunotherapy is treatment that uses your own body’s defense system to help itself. Because I have identified, through allergy testing, what the patient is allergic to, I can prescribe the patient sublingual immunotherapy (SLIT) to be used at home daily to build up the patient’s immune system. Basically, all things the patient is allergic to are reconstituted into drops that patients introduce into their bodies. Through the course of three to six months, the patient can administer drops under his or her tongue, which slowly through time, treats the underlying allergy and modifies the patient’s immune system so he or she becomes less symptomatic. Previously, only allergy shots, or subcutaneous immunotherapy, which required weekly visits to the allergist, were available. This process can be outside our scope in some states; consult state guidelines for clarity.
Triggering the Cascade
The two main factors that determine whether a person will become allergic to an antigen is genetic predisposition and exposure. Ocular allergies typically occur when one’s eye comes in contact with an allergen, and it irritates the conjunctiva. Mast cells, which are the gatekeepers to immune system response, are a type of white blood cell that contain histamine and heparin, and are found in the ocular tissues. When the initial exposure to an antigen occurs, the body produces Immunoglobulin E-mediated antibodies that are attached to the mast cells. When re-exposure of the antigen occurs again, the mast cells become activated and release inflammatory mediators, such as histamine and cytokines (leukotrienes and prostaglandins), which cause the ocular symptoms. Symptoms can generally include burning, itching, tearing, redness and edema and are typically worse with outdoor allergies vs. indoor allergies.
GET TO THE ROOT CAUSE
Managing ocular allergies can be both challenging and rewarding, as can following your favorite baseball team. Getting at the root cause is key. My Minnesota Twins have not had stellar years lately, but look at what the Cubs did last year. The Twins will need to figure out why their hitting percentages are low and how to perform better on defense, or sort out the root cause issues. Remember, when you keep working at getting to the root cause of any adverse situation, you will likely find a satisfactory solution. OM