Tests for Sjögren's syndrome vary from the very simple to the very technical but in most cases a few simple tests will be sufficient to confirm the diagnosis. The medical community across the UK , Europe and America have now agreed on 6 specific criteria of which at least 4 must be present to confirm the diagnosis.
The first two of these criteria simply involve asking you 6 specific questions about your dryness, three relating to mouth and three to eye dryness. They are:
- Have you had a daily feeling of dry mouth for more than 3 months?
- Have you had recurrently or persistently swollen salivary glands as an adult?
- Do you frequently drink liquids to aid in swallowing dry foods?
- Have you had daily, persistent, troublesome dry eyes for more than 3 months?
- Do you have a recurrent sensation of sand or gravel in the eyes?
- Do you use a tear substitute more than 3 times a day?
Next the doctor needs to assess how dry your mouth actually is. Sometimes this is just done by looking at the inside of your mouth an under your tongue. The amount of dental work that you have had done and the extent of any tooth decay is also a helpful sign . Often the salivary flow rates can be measured by asking you to 'dribble' into a dry container over period of five minutes or so. In some cases more specific test are requested such as stimulated salivary flow (where lemon juice is usually used to provoke flow of saliva) or scans of the salivary glands. Various types of scan are used to look at the glands and ducts within them e.g. scintigraphy, sialograms, ultrasound scans or MRI. Your specialist would advise if any of these more specific scans is required.
To assess the tear flow the commonest test is called 'Schirmers test' and involves placing small strips of blotting paper inside the lower eyelid. This takes 5 minutes and should cause no more than mild and temporary discomfort. More specialised tests are often done by opthalmologists (eye doctors), these usually involve putting drops in the eyes to temporarily stain damaged areas on the surface of the eye.
Many units will arrange for you to have a minor salivary gland or 'lip biopsy'. This involves an injection of local anaesthetic into the inner surface of the lower lip, a shallow incision and the removal of a few of your 'minor salivary glands. If you run your tongue along inside your lower lip you should be able to feel these glands very close to the surface. They are about the size of a matchhead and the whole of the inside of the mouth is lined with them. The glands that are removed are sent to the laboratory and examined under the microscope for signs of Sjögren's syndrome.
Finally there are two specific blood tests that are useful in making the diagnosis. These are looking for the presence of two specific auto-antibodies in the blood - anti-Ro and anti-La. They are sometimes also referred to as SS-A and SS-B reflecting their importance in Sjögren's. However they are only present in about 60% of patients with Sjögren's syndrome so it is perfectly possible to have negative results and still have the condition.
In addition to all the above your doctor may well check for other things such as anaemia which can be found in association with the condition.
