Sjögren's syndrome

Definition and classification. A chronic autoimmune exocrinopathy in which lymphocytic infiltration of exocrine glands causes dry eyes and dry mouth. Primary Sjögren's occurs alone; secondary Sjögren's accompanies rheumatoid arthritis, SLE or systemic sclerosis. Strongly female-predominant (about 9:1), with onset typically in the fifth to sixth decade and a further peak in older women.

Glandular clinical features. Keratoconjunctivitis sicca — gritty, burning eyes, photophobia, corneal filaments. Xerostomia — difficulty swallowing dry food, altered taste, rampant dental caries, oral candidiasis, angular cheilitis, difficulty retaining dentures. Also parotid or submandibular gland enlargement, dry skin, dry cough from tracheobronchial dryness, and vaginal dryness with dyspareunia.

Extraglandular features. Non-erosive arthritis, Raynaud's phenomenon, interstitial lung disease, renal tubular acidosis and interstitial nephritis, peripheral and small-fibre neuropathy, cutaneous vasculitis, and autoimmune thyroid disease. Profound fatigue is often the most disabling symptom. The risk of non-Hodgkin (MALT) lymphoma is increased roughly 5–15 fold — persistent parotid swelling, low C4, cryoglobulins and palpable purpura are the warning signs.

Investigations. Anti-Ro/SSA and anti-La/SSB antibodies, ANA and RF positive; raised ESR with a normal CRP; polyclonal hypergammaglobulinaemia; cytopenias; low complement. Objective tests: Schirmer's test ≤5 mm in 5 minutes, ocular staining score, unstimulated whole salivary flow ≤0.1 mL/min, and labial minor salivary gland biopsy showing focal lymphocytic sialadenitis with a focus score ≥1. Diagnosis uses the ACR/EULAR 2016 criteria (score ≥4).

The key geriatric differential — drug-induced dry mouth. Age-related salivary hypofunction and, far more commonly, medication are the usual causes of dry mouth in an older person: anticholinergics, tricyclic antidepressants, antihistamines, antipsychotics, diuretics, opioids and bladder antimuscarinics. Also consider previous head and neck radiotherapy, IgG4-related disease, sarcoidosis, hepatitis C, amyloidosis, HIV and diabetes. Always review the drug chart before diagnosing Sjögren's in an older patient.

Management. Largely symptomatic and preventive. Eyes — preservative-free artificial tears, ocular lubricant ointment at night, topical ciclosporin, punctal plugs. Mouth — frequent sips of water, sugar-free gum, saliva substitutes, and muscarinic agonists (pilocarpine or cevimeline), which must be used cautiously in the elderly (sweating, bradycardia, avoid in asthma, COPD and narrow-angle glaucoma). Intensive dental care with topical fluoride and treatment of oral candidiasis. Hydroxychloroquine for arthralgia and fatigue; glucocorticoids ± rituximab or other immunosuppression for severe systemic disease (vasculitis, ILD, neuropathy, glomerulonephritis). Stop or substitute the offending anticholinergic drugs.

Current EULAR practice directs therapy by systemic activity scoring using the ESSDAI, with symptom burden captured by ESSPRI, rather than treating everyone identically. More importantly, 2024–2025 phase 2 and phase 3 trials of targeted biologics have for the first time shown disease-modifying benefit: ianalumab (anti-BAFF-receptor), nipocalimab (FcRn blocker) and dazodalibep (CD40-ligand pathway inhibitor) all met their primary endpoints in Sjögren's disease — signalling the first prospect of therapy beyond symptomatic care. If this appears as a 15-mark question, add: the full ACR/EULAR 2016 criteria with individual item weights; pathogenesis (epithelitis, type I interferon signature, B-cell hyperactivity and BAFF); a table of causes of xerostomia in the older adult; the detailed lymphoma risk-stratification model; management of renal tubular acidosis and hypokalaemic paralysis (a classic Indian presentation); the ESSDAI domains; and the impact of xerostomia on nutrition, dentition, denture tolerance, taste, speech and quality of life in the elderly.