What is Sjögren's syndrome?

Sjögren's syndrome is a common autoimmune disease that often causes symptoms such as dry mouth and dry eyes. Even if you want to cry, you can't see tears. This disease is a global disease that occurs mostly in middle-aged women, with a very small proportion in the elderly. It may also occur in children.

1. Overview

Sjögren's syndrome (SS) is a chronic inflammatory autoimmune disease that primarily affects exocrine glands, also known as autoimmune exocrine gland epithelial cell inflammation or autoimmune exocrinopathy. Clinically, in addition to dry mouth and dry eyes caused by damaged salivary glands and lacrimal glands, other exocrine glands and extra-glandular organs are affected, resulting in symptoms of multi-system damage. There are multiple autoantibodies and hyperimmunoglobulinemia in their serum. This disease is divided into two categories: primary and secondary.

Primary Sjögren's syndrome is a global disease with a prevalence of 0.3% to 0.7% in the Chinese population and 3% to 4% in the elderly population. This disease is more common in women, with a male to female ratio of 1:9 to 20. The age of onset is mostly between 40 and 50 years old. Also seen in children.

2. Local manifestations

(1) Xerostomia. Due to salivary gland lesions, salivary mucin deficiency causes the following common symptoms: ① Most patients complain of dry mouth. In severe cases, the oral mucosa, teeth and tongue become sticky, so the patient needs to drink water frequently when speaking, and solid food must be taken with water or liquid food. ② Rampant dental caries is one of the characteristics of this disease. About 50% of patients develop multiple uncontrolled caries, which are manifested by the gradual darkening of the teeth, followed by small pieces falling off, and ultimately leaving only residual roots. ③ In adult mumps, 50% of patients present with intermittent alternating parotid swelling and pain, involving one or both sides. Most of them can disappear on their own in about 10 days, but sometimes the swelling persists. A few people have submandibular gland enlargement, while sublingual gland enlargement is less common. ④ The tongue manifests as tongue pain, dry and cracked tongue surface, and atrophied and smooth tongue papillae. ⑤Ulcers or secondary infections occur in the oral mucosa.

(2) Keratoconjunctivitis sicca. This is due to the decrease in mucin secretion by the lacrimal glands, which causes symptoms such as dry eyes, foreign body sensation, and less tears. In severe cases, the patient may cry without tears. Some patients have recurrent purulent infections of the eyelid margin, conjunctivitis, keratitis, etc.

(3) Others. Exocrine glands in superficial areas such as the nose, hard palate, trachea and its branches, gastrointestinal mucosa, and vaginal mucosa can all be affected, causing their secretion to decrease and resulting in corresponding symptoms.