Vol. 2, #14   •   Thursday, June 24, 2021


Review's Chief Clinical Editor
Paul M. Karpecki, OD, FAAO

Provides you with cutting-edge clinical strategies for optimal management of ocular surface disease and beyond.


Allergy & Dry Eye Overlap

One of the more difficult differentiations from dry eye can be allergic conjunctivitis.

In many cases, patients who present to your office with itchy, dry eyes are dealing with dry eye, allergic conjunctivitis (AC), or some combination of the two. Since allergies are a common cause of dry eye flares, I often see an uptick in these cases in the spring where I practice in Kentucky, when allergies and pollen counts are elevated.

Research validates the obstacles in differentiating these two conditions. In a study by Hom, et al. looking at 698 patients presenting with symptoms of dryness or itching, of 194 patients with itchiness, 57.7% had clinically significant dryness, and in 247 patients with dry eyes, 45.3% had clinically significant symptoms of itching.1 In addition, conjunctival erythema (redness) as a patient symptom wasn’t a differentiator since about 62% of patients with itching and 49% with dryness had redness as a clinical finding.

So how can we differentiate one condition from the other or determine if overlap is present?

Potential Questions to Differentiate AC From DED
There are a few questions you can ask patients to try and differentiate allergic conjunctivitis (AC) from dry eye. The first is: Where is the itching? If the patient points to the canthal region or reports the eyes in general are the source, consider a diagnosis of AC. If the patient pinpoints their lashes or lid margins, look for collarettes indicating demodex blepharitis since this condition can present with true evaporative dry eye disease and a primary symptom of itching.

Also ask the patient about a history of allergies/atopy and rhinitis. The TFOS DEWS II Diagnostic Methodology report noted that the vast majority of patients with allergic conjunctivitis experience rhinitis while very few DED patients have rhinitis.2

Finally, since allergies are a common cause of dry eye flares, be on the lookout for seasonal pollen count elevation, as dry eye flares now have an FDA-approved therapeutic in EYSUVIS. Patients can be dosed up to QID for 2 weeks. In my experience, there is no more effective therapy than short-term loteprednol-based steroids (e.g., EYSUVIS) to suppress the inflammation associated with a dry eye flare.

KEY TAKEAWAY: The symptoms of dry eye and allergic conjunctivitis have significant overlap so ask questions about the location of itching and presence of rhinitis to help differentiate the conditions. An approved therapeutic (EYSUVIS) for the short-term treatment of signs and symptoms of DED can help address dry eye flares, including those caused by allergens.


1. Hom MM, Nguyen AL, Bielory L. Allergic conjunctivitis and dry eye syndrome. Ann Allergy Asthma Immu-nol. 2012 Mar;108(3):163-6.
2. Wolffsohn JS, Arita R, Chalmers R, et al. TFOS DEWS II Diagnostic Methodology report Ocul Surf. 2017 Jul;15(3):539-74.

Supported by an independent medical grant from Kala Pharmaceuticals

Review of Optometry® is published by the Review Group, a Division of Jobson Medical Information LLC (JMI), 19 Campus Boulevard, Newtown Square, PA 19073.

To subscribe to other JMI newsletters or to manage your subscription, click here.

To change your email address, reply to this email. Write "change of address" in the subject line. Make sure to provide us with your old and new address.

To ensure delivery, please be sure to add revoptom@lists.jobsonmail.com to your address book or safe senders list.

Click here if you do not want to receive future emails from Review of Optometry.