How is Sjögren's syndrome diagnosed?
Primary Sjögren's syndrome
The diagnosis of Sjögren's syndrome is based on several factors, including:
- Presence of dry eyes and mouth. Dry eyes can be diagnosed by an ophthalmologist (eye doctor) by measuring tear production or carefully examining the cornea (clear part of the eye).
- Certain laboratory tests also suggest that dry eyes and mouth are caused by autoimmune mechanisms. Examples include the presence of autoantibodies in the blood, known as ANA, anti-SSA, or anti-SSB (also known as anti-Ro or anti-La), and even rheumatoid factor.
- Biopsy of the inner lip (performed in some cases to prove the diagnosis of primary Sjögren's syndrome). The biopsy may show the inflammation that is damaging the salivary glands.
Secondary Sjögren's syndrome
Secondary Sjögren's syndrome is generally diagnosed when someone with an established autoimmune disease such as rheumatoid arthritis or systemic lupus erythematosus develops extreme dryness of the eyes and mouth. This diagnosis only rarely requires a lip biopsy.