Abstract and Introduction
Primary SS (pSS) is a systemic autoimmune disease characterized by lymphocytic infiltration of the exocrine glands leading to glandular dysfunction, resulting in dryness of the eyes, mouth and other mucosal surfaces. Systemic manifestations also occur in the majority of patients. There has been increasing interest in recent years, with a number of publications regarding the classification criteria, diagnostic tools, disease activity, damage, impact and potential treatments. This article reviews recent advances in the diagnosis and treatment of ocular and oral involvement in pSS. Recent stand-out developments include measurement of tear osmolarity as a marker in dry eye disease diagnosis, new devices measuring tear constituents and meibomian gland structure and treatment of its dysfunction. Lip biopsy is still valuable despite emerging evidence of non-invasive diagnostic techniques, notably salivary gland ultrasound.
SS is one of the most common autoimmune diseases. It exists as either a primary syndrome or as a secondary disorder when associated with other autoimmune diseases, such as RA, SLE or SSc. It is an immune-mediated condition of unknown aetiology characterized by focal lymphocytic infiltration of the exocrine glands. This causes dryness of the eyes, mouth and other mucosal surfaces and systemic manifestations including fatigue and arthralgia can occur. Systemic features may affect up to 70% of patients and include inflammatory arthritis, skin involvement, haematological abnormalities, neuropathies, interstitial lung disease and a 5–10% lifetime risk of B cell lymphoma.
Primary SS (pSS) typically presents in women in their fifth or sixth decade, although up to 10% of cases occur in men. Studies using the American–European Consensus Group (AECG) criteria have estimated the prevalence in women in the UK at 0.1–0.4%.
The most widely accepted classification criteria for pSS are the AECG criteria and the 2016 ACR–EULAR criteria. The AECG criteria require four of six dry eye and dry mouth symptoms, objective ocular dryness (Schirmer test ≤5 mm in 5 min or van Bijsterveld score ≥4), objective oral dryness (unstimulated salivary flow rate ≤0.1 ml/min or positive salivary scintigraphy and sialography), positive anti-Ro/La antibodies and a labial gland focus score ≥1 and including at least one of the last two objective features.
The 2016 ACR–EULAR classification criteria are based on the weighted sum of five items and require a total score ≥4 to meet the criteria for pSS: anti-Ro antibodies and focal lymphocytic sialadenitis with a focus score ≥1, each scoring 3; abnormal ocular staining score ≥5, Schirmer test result ≤5 mm in 5 min and an unstimulated salivary flow rate ≤0.1 ml/min, each scoring 1.
A number of guidelines have been published for pSS. The British Society for Rheumatology guideline for the management of ocular and oral manifestations and systemic disease were published in 2017. The EULAR and Sjögren's Syndrome Foundation also published their guidelines.[7,8] Management of the glandular features includes conserving, replacing and stimulating secretions while reducing inflammation. Systemic features may require system-specific therapy and immunomodulatory treatment. This article aims to review new developments in ocular and oral disease in pSS. Many of these developments also apply to SS in general.
Rheumatology. 2021;60(3):1034-1041. © 2021 Oxford University Press