Medicine – Sjögren’s Syndrome

Sjögren’s syndrome is a chronic autoimmune connective tissue disorder characterised by lymphocytic infiltration and progressive dysfunction of the exocrine glands. The lacrimal and salivary glands are particularly affected, resulting in the characteristic combination of dry eyes and dry mouth. Other exocrine glands may also be involved, producing dryness at several mucosal surfaces. In addition to glandular manifestations, patients may develop musculoskeletal and vascular features such as arthralgia, arthritis, and Raynaud’s phenomenon.

1. Dryness Due to Exocrine Gland Involvement

Dryness is the principal clinical manifestation of Sjögren’s syndrome and results from lymphocytic infiltration, damage, and reduced secretion of the exocrine glands. Involvement of the lacrimal glands causes reduced tear production and dry eyes, known as keratoconjunctivitis sicca. Patients may complain of gritty or burning eyes, irritation, redness, or a sensation of having a foreign body in the eye.

Involvement of the salivary glands causes dry mouth, or xerostomia. Patients may have difficulty swallowing dry food, need to drink water frequently while eating, or experience difficulty speaking for prolonged periods. Reduced salivary production can also increase the risk of dental caries and oral infections.

Exocrine gland dysfunction is not necessarily restricted to the eyes and mouth. Reduced secretions within the respiratory tract may cause dryness and irritation, while involvement of the female genital tract can result in vaginal dryness, which may cause discomfort and dyspareunia. Thus, widespread mucosal dryness is an important feature of the disease.

2. Arthralgia and Arthritis

Musculoskeletal manifestations are common, with approximately 60% of patients developing arthralgia or arthritis. Patients may experience pain, stiffness, and sometimes swelling affecting several joints. The arthritis is generally inflammatory but is usually non-erosive, meaning that it does not typically produce the progressive joint destruction characteristic of rheumatoid arthritis.

3. Raynaud’s Phenomenon

Approximately 37% of patients may experience Raynaud’s phenomenon. This occurs because of episodic vasospasm of the small blood vessels supplying the fingers and, less commonly, the toes. Attacks are often precipitated by cold exposure or emotional stress, and the affected digits may sequentially become pale, blue, and then red as circulation returns. Patients may also experience numbness, tingling, or discomfort during an episode.

Key Clinical Picture

The characteristic clinical picture of Sjögren’s syndrome is therefore prominent dryness of the eyes and mouth due to autoimmune destruction of the lacrimal and salivary glands, accompanied in many patients by arthralgia or arthritis and Raynaud’s phenomenon. The combination of dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) is particularly important in recognising the disorder.