Sjögren syndrome (SS) is a common autoimmune disease primarily affecting the eyes and mouth. With no single gold standard test for its diagnosis, accurate identification of patients with SS continues to be challenging. We aimed to assess the correlation of ocular and oral symptoms of dryness with objective measures in order to evaluate reliability in the screening of primary SS (pSS) in clinical practice.

We conducted a cross-sectional analysis of pre-screened pSS and sicca control patients assessed in the Multidisciplinary Sjögren's Clinic at the University Health Network in Toronto. The signs, symptoms, and objective measure of oral and ocular dryness and damage of each patient were prospectively recorded using a standardized protocol.

Subjective measures of severity for xerophthalmia and xerostomia correlated in general with objective severity. Oral symptoms tend to have a stronger correlation with objective findings than ocular symptoms. Many patients with few or insignificant eye symptoms had profound ocular dryness and damage. Similarly, some patients with few or no symptoms of oral dryness had profound objective salivary hypofunction. The absence of symptoms does not rule out profound eye and mouth dryness or damage.

Although objective measures of xerostomia may not be practical for general population screening, it is crucial that practicing specialists perform objective testing of all patients suspected of pSS, instead of relying on symptoms. Without objective testing, the physician cannot ensure the diagnosis of pSS and that the existence of significant damage is not overlooked and left untreated.