Circuit 4, station 7

Clinical features • Dry mouth in oral medicine clinic OR • White patch in the mouth • Up to a third can have parotid swelling

Sicca syndrome is the combination of dryness of the eyes (xeropthalmia), oral cavity (xerostomia), pharynx and/or larynx, which are the classical symptoms of pSS (primary Sjögren Syndrome). In women, vaginal dryness is also a common feature of pSS.

Oral symptoms – a positive response to at least one of the following questions:
• 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 food?

Common causes of dry mouth
Medications, including antidepressants, anticholinergics, antispasmodics, antihypertensives, antihistamines, sedatives, and diuretics
• Sjögren Syndrome
• Diabetes mellitus (type 1 and type 2)
• Head and neck irradiation
• Dehydration
• Parkinson’s disease
Investigations for dry mouth
There are a number of methods to measure the degree of a dry mouth, and whether it is true or not.

Salivary flow rate which measures the rate of production of saliva in mouth:
Method 1: collect mixed saliva from the mouth over a certain length of time e.g. 1 minute, and ask the patient to spit into a universal tube. This can be done at rest and after chewing a piece of wax to get a stimulated flow rate.

Method 2: collect from an individual salivary gland e.g. testing parotid flow rate. This is then measured using a Carlsson Critteenden cup which fits over the parotid duct orifice in the buccal vestibule. This is done at rest or by stimulating the flow by placement of a dilute solution of citric acid on tongue.

Ocular or eye tests:
The lacrimal gland flow by Schirmer’s test is the standard method.

Tear production often decreases when salivary flow rate is also decreased. Place a filter paper under the lower eyelid for 5 mins and measure how far moisture travels. A rate of < 5 mm is indicative of reduced tear production. Other causes of an abnormal Schirmer’s test – Drug-induced: Anticholinergics, antihistamines, tricyclic antidepressants, diuretics – Age-related/menopause – Status post head/neck radiation – Chronic viral infections (HCV, HIV) – Sarcoidosis, lymphoma – IgG4-related disease Other investigations Labial gland biopsy: Take a sample from small salivary gland from lower lip via a local anaesthetic, a small cut and the sutured cut heals within a week. Sialography: Inject radio-opaque dye into the salivary gland duct and take X-rays. This shows the architecture, and any strictures, stones or filling defects along with any functional abnormalities. Scintigraphy: Intravenous injection of radioactive dye - usually technecium 99m pertrechnetate. The measured uptake is assessed by gamma camera to visualise the functional salivary gland tissue. Blood tests: Full blood count looks for other causes such as an infection (raised white cell count) and allergy (raised eosinophils). Erythrocyte sedimentation rate (ESR) will be raised. Autoimmune antibodies: Anti-nuclear antibody (ANA) raised in 55-97% of cases Anti-SSA (Ro) raised in 16-70% of cases Anti-SSB (La) raised in 7-50% of cases Rheumatoid factor (RF) raised in 32-90% of cases Complications of Sjögren syndrome There is a risk of MALT - mucosa associated lymphoid tissue, lymphoma B cell lymphoproliferative as a later change in Sjögren syndrome, which could be indicated if there is present a firm enlargement of one or more glands. If suspected, after biopsy, refer under the suspected cancer pathway to Head and Neck Surgery.