シェーグレン症候群
Xerostomia may be caused by autoimmune conditions which damage saliva-producing cells. Sjögren's syndrome is one such disease, and it is associated with symptoms including fatigue, myalgia and arthralgia. The disease is characterised by inflammatory changes in the moisture-producing glands throughout the body, leading to reduced secretions from glands that produce saliva, tears and other secretions throughout the body. Primary Sjögren's syndrome is the combination of dry eyes and xerostomia. Secondary Sjögren's syndrome is identical to primary form but with the addition of a combination of other connective tissue disorders such as systemic lupus erythematosus or rheumatoid arthritis.