Primary Sjögren's syndrome: oral aspects on pathogenesis, diagnostic criteria, clinical features and approaches for therapy.

Primary Sjögren's syndrome (pSS) is a chronic inflammatory systemic autoimmune disease affecting the exocrine glands and predominantly the salivary and lacrimal glands. The impaired gland function is assumed to be a result of progressive lymphocyte-mediated destruction of the exocrine gland tissue leading to the cardinal manifestations, hyposalivation and keratoconjunctivitis sicca (KCS), as well as devastating symptoms of oral and ocular dryness. Although primarily characterised as an exocrine dysfunction, non-exocrine organs may also be affected. The onset and course of pSS is usually insidious but may develop into a disabling disease, which profoundly affects the patient's general well being and quality of life. Moreover, pSS may even evolve into a lymphoid malignancy. The aetiology of pSS remains unknown but the pathogenesis of exocrine cell damage is apparently multi-factorial, including immunological, genetic, hormonal and viral components. Recent research also includes neurogenic aspects of exocrine gland dysfunction, including the interference of immune mediators with glandular response to neurotransmitters released from nerve fibres. pSS usually affects middle-aged women and the female:male ratio is 9:1. The prevalence varies from 0.29-4.8%, depending on the population sampled and the diagnostic criteria used. At present, there are no specific diagnostic tests for pSS and no universally accepted diagnostic criteria. The current therapy is primarily symptomatic. This review focuses on the current oral clinical, diagnostic, pathogenic and therapeutic aspects of pSS.