Sjögren’s Syndrome is a systemic autoimmune disorder where the body’s immune system mistakenly targets its own moisture-producing glands. This disease primarily affects the exocrine glands, which are responsible for secreting fluids like tears and saliva. The salivary glands become a significant site of inflammatory attack, leading to a profound reduction in saliva production. This gland dysfunction is central to the condition’s most common and disruptive symptoms, affecting oral health and quality of life.
The Immune Attack on Salivary Tissue
The underlying mechanism in Sjögren’s Syndrome involves a severe malfunction of the immune system directed against the salivary glands. This destructive process begins when immune cells, primarily a type of white blood cell called lymphocytes, infiltrate the glandular tissue. These lymphocytes, mostly T cells and B cells, gather in dense clusters around the salivary ducts, a process known as focal lymphocytic infiltration.
This infiltration triggers chronic inflammation that progressively damages the acinar cells, which are the specialized cells responsible for producing and secreting saliva. The immune assault is thought to be driven by the recognition of autoantigens exposed by the epithelial cells of the salivary glands, leading to the activation of T and B cells. The sustained presence of these inflammatory cells causes the atrophy and ultimate destruction of the secretory tissue.
As the acinar cells are destroyed, the gland’s ability to produce saliva declines dramatically, leading to glandular hypofunction. This loss of secretory function is the direct consequence of the body’s own immune system dismantling the structures meant to generate moisture. The damage can sometimes lead to the formation of ectopic germinal centers within the glands, where B cells produce autoantibodies and perpetuate the autoimmune cycle.
Recognizing Salivary Gland Symptoms
The profound reduction in saliva flow, known medically as hyposalivation, manifests as the chronic symptom of dry mouth, or xerostomia. Patients often describe this sensation as a persistent stickiness or burning in the mouth, which is present even when not eating. This lack of lubricating saliva makes it difficult to chew and swallow dry foods, a problem known as dysphagia, and can interfere with clear speech.
Saliva is important for taste perception, and its reduction can lead to changes in the ability to taste food, a symptom called dysgeusia. The remaining saliva may become thick, stringy, or foamy due to the change in its composition.
Without the protective and cleansing action of normal saliva, patients become highly susceptible to secondary oral complications. These secondary issues include an increased rate of dental decay and cavities, as saliva normally neutralizes acids and remineralizes tooth enamel. The lowered flow also raises the risk of oral fungal infections, most commonly oral candidiasis. This infection can present as white patches or painful redness on the tongue and inner cheeks, or as sores at the corners of the lips, known as angular cheilitis.
Assessing Gland Function and Damage
Diagnosis of Sjögren’s Syndrome involves objective measures to evaluate the function and structure of the salivary glands. One primary method is sialometry, which precisely measures the rate of saliva production. This test typically involves collecting both unstimulated whole saliva and stimulated saliva collected after chewing on a substance like paraffin. An abnormally low flow rate provides objective evidence of glandular dysfunction, though it is not exclusive to Sjögren’s.
The most specific test to confirm the autoimmune damage is the minor salivary gland biopsy, often taken from the lower lip. This procedure involves removing a small sample of the minor glands for microscopic examination.
The tissue sample is analyzed for the hallmark sign of the disease: focal lymphocytic infiltration. The severity of the infiltration is quantified using a focus score, which represents the number of inflammatory cell clusters in a specific area of glandular tissue. A focus score greater than one cluster per four square millimeters of tissue has a high specificity for Sjögren’s Syndrome. Imaging techniques, such as sialography or scintigraphy, may also be used to assess the structure of the major salivary glands.
Strategies for Managing Dry Mouth
Management focuses on alleviating the symptoms of xerostomia and protecting the oral cavity from its damaging effects. Over-the-counter interventions offer immediate relief and include the regular use of saliva substitutes, often available as sprays or gels, to moisten the oral mucosa. Simple measures like sipping water frequently, especially during meals to aid chewing and swallowing, and using a humidifier at night are also recommended.
For individuals with residual salivary gland function, prescription medications can be used to stimulate saliva production. These drugs, known as secretagogues, include pilocarpine and cevimeline. Both medications work by activating muscarinic receptors on the salivary glands, prompting them to produce more fluid.
Scrupulous preventative dental care is important to counteract the increased risk of tooth decay. This includes brushing twice daily with a fluoride toothpaste and using alcohol-free fluoride rinses. Patients are often advised to chew sugarless gum or lozenges, particularly those containing xylitol, to stimulate mechanical saliva flow and reduce cavity risk. Avoiding substances that further dry the mouth, such as caffeine, alcohol, and tobacco, is also a standard part of the management strategy.