How to diagnose Sjögren's (Sjögren's) syndrome?

Diagnosing Sjögren's Syndrome

The diagnosis of Sjögren's syndrome requires a comprehensive evaluation including specific serological testing, ocular examination, and assessment for systemic manifestations.

Clinical Evaluation

Key Symptoms to Assess

• Ocular symptoms:

  • Dry eyes, irritation, itching, or pain
  • Foreign body sensation
  • Light sensitivity
  • Frequent use of eye drops
  • Blurry vision or unexplained vision changes 1

• Oral symptoms:

  • Dry mouth
  • Need for liquids to swallow dry foods
  • Frequent sipping/drinking water
  • Burning sensation in the mouth
  • Angular cheilitis (painful sores at corners of mouth)
  • Frequent dental cavities (especially gumline)
  • Teeth chipping, cracking, or eroding
  • Gum inflammation 1

• Other key symptoms:

  • Swollen parotid or submandibular glands
  • Vaginal dryness
  • Skin dryness or itching
  • Peripheral neuropathy (numbness, burning pain)
  • Extreme fatigue
  • Joint or muscle pain
  • Raynaud's phenomenon 1, 2

Diagnostic Testing Algorithm

Step 1: Ocular Examination

• Tear film assessment:

  • Tear meniscus height along inferior eyelid
  • Tear break-up time and pattern
  • Debris, viscosity, mucous strands, foam 1

• Ocular surface evaluation:

  • Fluorescein staining of cornea
  • Lissamine green or rose bengal staining of conjunctiva
  • Schirmer's test (< 5.5mm wetting after 5 minutes indicates aqueous tear deficiency) 1

Step 2: Serological Testing

• Primary serological panel:

  • Anti-SSA/Ro antibodies
  • Anti-SSB/La antibodies
  • Antinuclear antibody (ANA)
  • Rheumatoid factor (RF) 1, 2

• Additional biomarkers:

  • Salivary protein 1 (SP1)
  • Carbonic anhydrase 6 (CA6)
  • Parotid secretory protein (PSP) 1, 3

Step 3: Additional Testing

• Salivary gland assessment:

  • Unstimulated salivary flow rate (< 0.1 ml/minute is abnormal)
  • Minor salivary gland biopsy (if needed) 1, 2

• Systemic evaluation:

  • Complete blood count
  • Comprehensive metabolic panel
  • C4 complement levels (decreased levels indicate higher lymphoma risk) 1, 2

Diagnostic Criteria

A patient meets the criteria for primary Sjögren's syndrome with a total score of ≥4 based on the weighted sum of:

• Anti-SSA/Ro antibody positivity (3 points)
• Focal lymphocytic sialadenitis with focus score ≥1 foci/4 mm² (3 points)
• Abnormal ocular staining score ≥5 (1 point)
• Schirmer's test result ≤5 mm/5 minutes (1 point)
• Unstimulated salivary flow rate ≤0.1 ml/minute (1 point) 1, 2

Important Considerations

• Early diagnosis is crucial as Sjögren's syndrome patients have increased risk for:

  • Ocular complications (scleritis, sterile keratitis, uveitis)
  • Lymphoproliferative disorders
  • Vasculitic complications 1, 2

• Differential diagnosis:

  • Medication-induced dry eye/mouth
  • Age-related dryness
  • Other autoimmune disorders (rheumatoid arthritis, lupus)
  • Sarcoidosis
  • Thyroid eye disease 1

• Common pitfalls:

  • Focusing only on sicca symptoms and missing systemic manifestations
  • Not testing for serological markers in patients with aqueous-deficient dry eye
  • Failing to monitor for lymphoma development, especially in patients with decreased C4 levels 2, 3

Referral Recommendations

• Rheumatology referral is essential for all patients with suspected or confirmed Sjögren's syndrome for evaluation of systemic manifestations and management 1, 2

• Pulmonology consultation should be considered for patients with respiratory symptoms, as approximately 10% develop pulmonary complications 1, 2