Start your drops: Allergy season has arrived

An eye care professional should examine allergy-suffering patients to exclude other underlying or confounding conditions.

Issue: May 10, 2017

ByMitchell A. Jackson, MD

As a practicing premium eye surgeon in the Midwest, there are really four seasons in the year, and spring represents the start of allergy season and when I recommend to my allergy-suffering patients to start their allergy eye drops.

Ocular allergies affect millions in the U.S., as proof by the greater than 41 million bottles of over-the-counter and 4 million bottles of prescription anti-allergy ophthalmic medications consumed annually. Seventy percent to 80% of people affected by allergies report ocular symptoms, and up to 40% of the U.S. population is affected by allergic conjunctivitis. Seasonal and perennial allergic conjunctivitis accounts for 95% of all ocular allergy cases in the U.S. Seasonal allergies are commonly caused by tree and flower pollen in the spring, grass pollen in late spring/early summer and ragweed pollen in late summer/early fall. Perennial allergies are commonly caused by dust mites, cat and dog dander, and household molds.

Despite the consumption of OTC allergy medication, assessment and examination by an eye care professional are critical to exclude other underlying and/or confounding morbidities or conditions, such as dry eye, blepharitis, meibomian gland dysfunction, preservative toxicity, systemic diseases and/or medications. The diagnosis of ocular allergy is typically made by history and clinical examination, with the most common signs and symptoms being ocular itching, tearing, conjunctival hyperemia/chemosis and eyelid edema; up to 90% have concomitant nasal rhinitis.

The allergic response

The allergic response is a type I immunoglobulin E-mediated hypersensitivity reaction with an early and late phase, in which both phases manifest clinically with itch, redness and/or chemosis. The early phase begins when the allergen triggers mast cell degranulation in sensitized individuals. Preformed mediators such as histamine, tryptase, chymase and heparin are released immediately upon allergen exposure, which leads to an early phase response of itch, redness and/or chemosis within seconds and can last up to 40 minutes after exposure. The preformed tryptase and histamine promote chemotaxis of basophils and eosinophils to the area of the allergic response as well.

The late phase occurs approximately 4 to 6 hours after the initial allergen exposure. Newly formed mediators such as platelet-activating factor, leukotrienes, prostaglandins, cytokines and chemokines are released. Recruitment of additional inflammatory cells such as neutrophils and eosinophils into the conjunctiva occurs within 6 to 10 hours after allergen exposure, with later infiltration of lymphocytes. In addition to the mast cells already present, basophils and eosinophils are recruited to the conjunctival tissue and produce additional inflammatory mediators that exacerbate and/or perpetuate the immune response 6 to 24 hours after allergen exposure and are responsible for the majority of signs and symptoms of allergic conjunctivitis.

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Treatment paradigm

Tailoring treatment to the degree of severity of the signs and symptoms is important. First and foremost, avoidance of the causative allergen(s) is critical, such as staying indoors during high pollen/mold counts, using room and car air conditioning, keeping windows closed (“bubble” effect), washing hair and clothes after being outside (showers at bedtime), using dust mite covers for pillows and mattresses, and using HEPA filters. Also consider hypoallergenic pets such as Devon Rex cats (my personal experience).

Initial medical treatment approaches can include artificial tears (chilled for enhanced effect), cool compresses (frozen bag of peas/corn for easy access) and OTC topical decongestants, which typically are vasoconstrictors that can produce unwanted tachyphylaxis and rebound hyperemia. Prescription therapy can include topical steroids such as Alrex (loteprednol 0.2%, Bausch + Lomb) with its ocular surface-friendly glycerin moisturizer; mast cell stabilizers (prevention purposes such as sodium cromoglycate); systemic and topical antihistamines, preferably the latter selectively blocking H1 receptor to avoid exacerbating dry eye such as Bepreve (bepotastine besilate 1.5%, Bausch + Lomb) or Lastacaft (alcaftadine 0.25%, Allergan); topical NSAIDs, which decrease pruritic symptoms caused by PGE2 and PGI2; and/or dual-acting antihistamines and mast cell stabilizers.

Occasionally, systemic and/or nasal/inhaled steroids are needed or a visit to an allergist is needed for subcutaneous injections weekly. Allergy skin testing should always be performed to be sure patients are not taking oral antihistamines unnecessarily because these will always exacerbate or cause dry eye via aqueous deficiency. Skin testing also aids the clinician on when to treat allergies and on what allergens to avoid if possible. I have been using the allergy skin testing system in-office routinely for the last few years, available as a turnkey process provided by Bausch + Lomb.

Management of ocular allergies is critical to the success of a healthy ocular surface, so as spring kicks into high gear, have your patients start your allergy treatment paradigm.

References:
Abelson MB, et al. Curr Allergy Asthma Rep. 2011;doi:10.1007/s11882-011-0188-5.
Bielory BP, et al. Acta Ophthalmol. 2012;doi:10.1111/j.1755-3768.2011.02272.x.
Bielory L, et al. Immunol Allergy Clin North Am. 2008;doi:10.1016/j.iac.2007.12.005.
Butrus S, et al. Ophthalmol Clin North Am. 2005;doi:10.1016/j.ohc.2005.07.007.
Irkec MT, et al. Curr Opin Allergy Clin Immunol. 2012;doi:10.1097/ACI.0b013e328357a21b.
O’Brien TP. US Ophthalmic Review. 2012;doi:10.17925/USOR.2012.05.01.53.

For more information:
Mitchell A. Jackson, MD, can be reached at Jacksoneye, 300 N. Milwaukee Ave., Suite L, Lake Villa, IL 60046; email: mjlaserdoc@msn.com.

Disclosure: Jackson reports he is a consultant for Bausch + Lomb and Allergan.