There are a variety of causes but the major ones are medication, especially tricyclic antidepressants and sympathomimetic drugs, head and neck irradiation, and auto-immune inflammatory diseases such as Sjogren’s syndrome, which targets exocrine glands in general[13]

There are a variety of causes but the major ones are medication, especially tricyclic antidepressants and sympathomimetic drugs, head and neck irradiation, and auto-immune inflammatory diseases such as Sjogren's syndrome,…