Sjogren Syndrome
Causes and Risk Factors
The exact underlying cause is unknown [Ref]
- More common in females (9:1 ratio)
- Age of onset: 45-55 y/o
- Associated with HLA-DQB1
- Triggers
- Viral infection (esp. EBV)
- Exposure to solvents and inorganic chemicals
Sjogren disease can be classified as primary or secondary: [Ref]
- Primary Sjogren syndrome: occurs as a stand-alone systemic autoimmune disorder
- Secondary Sjogren syndrome: occurs alongside another autoimmune disorder
- Most commonly SLE and RA
- Other associated autoimmune disorders include coeliac disease, autoimmune thyroid disease, PBC, scleroderma (systemic sclerosis)
Clinical Features
| Category | Clinical features |
|---|---|
| Core glandular (sicca) symptoms |
|
| Extra-glandular symptoms | Up to 50% of patients develop extra-glandular symptoms
Renal involvement is rare in Sjogren syndrome (if occur, it may manifest as RTA or tubulointerstitial nephritis, or glomerulonephritis) |
Investigation and Diagnosis
The following information is based on the 2016 ACR/EULAR classification criteria but is not intended to reproduce the full criteria.
| Category | Investigation and findings in Sjogren syndrome |
|---|---|
| Bedside tests | The following are objective tests for ocular and oral dryness
|
| Serology |
|
| Imaging |
|
| Biopsy | Biopsy is indicated when clinical and serological findings alone are insufficient to reach a diagnosis
|
Additional baseline screening is necessary as Sjogren syndrome frequently overlaps and coexists with other autoimmune conditions (secondary Sjogren syndrome):
- Vitamin D deficiency (deficiency is common and correlates with dry eye severity)
- TFT to check for thyroid disorders
- LFT +/- anti-mitochondrial antibodies (if PBC is suspected)
- Coeliac screen
- Serum bicarbonate to detect RTA
- Serum electrophoresis and immunoglobulins to check for hypergammaglobulinaemia or monoclonal gammopathy
- Creatine kinase to check for myositis
Management
| Category / manifestation | Management |
|---|---|
| Ocular dryness | Lifestyle advice to reduce tear evaporation
Pharmacological management
Omega-3 fatty acid supplementation and vitamin A eye ointments can be considered to support ocular surface health and reduce oxidative stress |
| Oral dryness | Lifestyle advice to prevent dental caries:
Symptomatic relief:
|
| Vaginal dryness | Topical non-hormonal vaginal moisturisers + topical oestrogen cream / pessary |
| Constitutional symptoms (fatigue, joint pain) | Trial of hydroxychloroquine |
| Flare-ups | Oral prednisolone (to be used for short-term only) |
DMARDs are reserved for those with progressive or organ-threatening complications:
- Methotrexate for inflammatory arthritis
- Mycophenolate mofetil for interstitial lung disease / cytopaenias
- Cyclophosphamide for severe myelopathy or glomerulonephritis
- Severe refractory systemic disease → consider biologics (e.g. rituximab, belimumab)