Sjögren syndrome

Sjögren syndrome is a systemic autoimmune disease, meaning a disease in which the body's defense system attacks the body itself and can do so in several places at once. In its primary form it presents mainly with sicca symptoms, from the medical word for dryness, especially of the eyes and the mouth.

What happens in the tissue has a name of its own: focal lymphocytic sialadenitis. It sounds complicated and it describes something concrete: inside the glands, foci appear as small clusters of mononuclear cells, most of them T lymphocytes, which are defense cells. Those clusters settle right up against the blood vessels and the ducts through which secretions drain. The tear and saliva factory is still there, but occupied by cells that do not belong to it.

The effect is what you would expect: the lacrimal glands make fewer tears and the salivary glands make less saliva. And because the same process can reach other exocrine glands, the ones that pour their product outward, the skin, the airway and the vagina can dry out too.