Diagnosis of Sjogren's Syndrome

Diagnostic Evaluation of Sjogren's Syndrome

A thorough diagnostic evaluation for patients with suspected Sjogren's syndrome usually includes the following:

  • Patient history
  • Physical examination
  • Oral examination
  • Eye examination
  • Laboratory studies
  • Other studies

Patient History

A detailed patient history is crucial in the diagnostic "work-up" for Sjogren's syndrome. Information gathered by the doctor usually includes:

  • History of symptoms - oral changes, ocular changes, fatigue, anxiety, joint or muscle pain
  • Duration and pattern of symptoms
  • Medications that the patient is presently taking that may cause similar symptoms
  • History of other comorbid conditions

Physical Examination

The physical examination relating to the diagnosis of Sjogren's syndrome is very important because it may reveal certain important aspects of the disease, including:

  • Salivary gland enlargement
  • Regional lymph node swelling and tenderness
  • Severely cracked lips
  • Ulceration of the tongue
  • Smooth tongue with atrophy of the papillae (taste buds)
  • Halitosis - bad breath
  • Pooling of saliva in the floor of the mouth
  • Appearance of the eyes (e.g., red, watery)
  • Excess production of mucus in lower part of eyes

Oral Examination

Studies that are performed to evaluate the extent and severity of oral symptoms in order to reach a diagnosis of Sjogren's syndrome include:

  • Sialometry - this is a test which measures salivary flow rate. Collection devises are placed over the various salivary glands while saliva flow is stimulated with citric acid. It evaluates stimulated and unstimulated saliva flow rates for a set period of time. A flow rate of 0.5L or less in 1 minute for stimulated saliva, or a flow rate of 0.5L or less in 5 minutes for unstimulated saliva is indicative of xerostomia (reduction of salivary production). This test cannot, however, distinguish between the various possible causes of xerostomia.
  • Parotid sialography - This is a radiographic evaluation of the salivary duct system and reveals any gross distortions of the parotid ductules such as a stone or a mass. An iodine containing contrast material is introduced into the ductal system and the distribution pattern of the contrast dye through the salivary ducts is observed.
  • Salivary (parotid) gland scintigraphy - This test is used to measure the timed uptake and excretion of a radioactive compound (technetium) by the major salivary glands and is a sensitive indicator of salivary gland function. It is also known as radionuclide imaging. In patients with Sjogren's syndrome, the uptake of the radioactive technetium compound is delayed and excretion into the oral cavity may not be noted at all.
  • Minor salivary gland biopsy (also called lip gland biopsy) - A biopsy sample of the minor salivary glands of the lower lip is obtained and is examined under a microscope to measure the extent of mononuclear cell infiltration. A Focus Score of 1 or higher, reflecting an aggregate of at least 50 mononuclear cells per 4 mm, is considered to be consistent with Sjogren's syndrome. This is a highly specific test for the components of saliva in Sjogren's syndrome patients and was in the past the "gold standard" technique used to diagnose Sjogren's syndrome (diagnostic criteria have since changed; see below). It may cause temporary soreness but healing is rapid with no significant scarring.
  • Parotid gland biopsy - performed in the presence of parotid gland swelling where lymphoma may be suspected.
  • Dental examination - a careful dental examination by a dentist should be performed to evaluate the presence of rampant tooth decay (dental caries) which may be one of the first signs of dry mouth.

Eye Examination

Tests to evaluate the extent and severity of dry eye include:

  • Schirmer test - This test is designed to evaluate the extent of dry eye by measuring the amount of tear production. Patients with Sjogren's syndrome usually produce less than 8 ml of tears over a 5-minute time interval.
  • Slit-lamp examination - This test is performed in conjunction with the Rose-Bengal dye test. Rose-Bengal dye is introduced into the conjunctival sac of the eye. After blinking twice, the slit-lamp examination evaluates the cornea for evidence of punctuate keratopathy (corneal irritation) as well as detects destroyed conjunctival tissue which may be due to keratoconjunctivitis sicca (dry eye).

Since keratoconjunctivitis sicca can be associated with other medical conditions, neither of these tests alone is diagnostic for Sjogren's but positive results of both tests combined confirms the diagnosis of Sjogren's syndrome.

Laboratory Studies

Laboratory studies that are performed to determine the presence of important markers of Sjogren's syndrome include:

  • Antinuclear Antibodies (ANA) - Approximately 90% of patients with primary Sjogren's syndrome have elevated antinuclear antibodies (ANA) in their blood suggestive of an autoimmune disorder.
  • Rheumatoid Factor (RF) - About 60% of patients with primary Sjogren's syndrome have elevated rheumatoid factor (RF) in their blood which is also consistent with an autoimmune disorder. It is important to note that detection of elevated levels of ANA or RF is not specifically diagnostic for Sjogren's syndrome since these substances may also be elevated in a broad range of other autoimmune, inflammatory, or infectious disorders.
  • The presence of so-called "Sjogren's antibodies" (Ro/SS-A and La/SS-B) in the blood is more specific for Sjogren's syndrome, however, these antibodies are also detected in a significant number of patients with systemic lupus erythematosus (SLE).
  • Immunoglobulin levels - Approximately 80% of patients with Sjogren's syndrome show signs of diffuse hypergammaglobulinemia (abnormally high levels of antibodies in the blood) specifically elevated levels of IgG, IgM, and IgA antibody subtypes.

Other Laboratory Studies

  • Complete Blood Count (CBC) - Blood tests for Sjogren's syndrome may reveal several abnormalities including:

    • leucopenia - reduced number of white blood cells
    • thrombocytopenia - reduced number of platelets
    • anemia - reduced number of red blood cells

  • Erythrocyte Sedimentation Rate (ESR) - this is elevated for the majority of Sjogren's syndrome patients

  • Chest X-ray
  • Other tests may be ordered by your doctor depending upon your specific symptoms

Upon diagnosis, the physician may see partial glandular destruction leading to dysfunction of remaining tissue. In addition, evidence of dry eye must be carefully evaluated as it is important to establish if the level of dry eye is compatible with the level of Sjogren's syndrome. Thus the doctor must make sure that the objective signs of dry eye are in agreement with the level of symptoms reported by the patient. In addition, while the lack of saliva may be a prominent symptom reported by the patient, it is not associated with any pain. If the patient complains of pain, other conditions causing dry mouth should be explored.