Objectives: To assess if isolated mouth or eye dryness constitutes distinct clinical phenotypes in Sjögren's disease (SjD).
Methods: We analysed 1765 patients meeting the 2016 ACR-EULAR SjD criteria, followed up at four centres in Greece and Italy (Universities of Pisa, Italy, and Athens, Harokopion, and Ioannina, Greece). Patients with isolated mouth or eye dryness were identified and matched 1:2 with those experiencing both symptoms, according to age at SjD diagnosis, gender, and disease duration. We defined two study groups: a) patients with ocular dryness only, and b) patients with oral dryness only, based on the AECG validated questionnaires for dryness. We compared glandular and extra-glandular manifestations, serology, and histologic features between each study and their matched controls.
Results: Seventy-two patients with isolated ocular dryness and 74 with isolated oral dryness were compared with 144 and 148 matched controls, respectively. Both groups had a median disease duration of 3 years. Patients with isolated eye dryness had lower frequency of salivary gland enlargement (35.4% vs. 28.7%, p=0.05) and lymphoma (0% vs. 11.3%, p=0.001). Conversely, those with isolated oral dryness had lower rates of arthralgias (39.1% vs. 65.5%, p=0.0003) and arthritis (8.6% vs. 20.3%, p=0.05). Isolated oral dryness was associated with older age at SjD diagnosis (median 53.5 vs. 46, p=0.005) and a higher likelihood of lymphoma (9.4% vs. 0%, p=0.01) compared to isolated ocular dryness.
Conclusions: Isolated ocular or oral dryness occurs in 8% of the general SjD population. Patients with isolated dry eyes have a lower prevalence of lymphoma compared to those with isolated dry mouth.