xerostomia
Summary
Xerostomia is dry mouth from reduced salivary flow. The commonest cause is medication with anticholinergic activity, and the most important disease cause is Sjogren syndrome.
Detail
Saliva protects the mouth, so its loss produces rampant dental caries especially at the gum line, candidiasis, difficulty chewing and swallowing dry food, altered taste, and burning mouth. Drug causes dominate: antimuscarinics, tricyclic antidepressants, antipsychotics, antihistamines, and diuretics. Sjogren syndrome is a chronic autoimmune lymphocytic infiltration of exocrine glands producing xerostomia plus keratoconjunctivitis sicca with a positive Schirmer test, often with parotid enlargement and arthralgia; it is associated with anti-Ro (SSA) and anti-La (SSB) antibodies, may be primary or secondary to rheumatoid arthritis or lupus, and carries a markedly increased risk of mucosa-associated lymphoid tissue (MALT) lymphoma, so a persistently enlarging parotid warrants biopsy. Anti-Ro also crosses the placenta and causes neonatal lupus with congenital heart block. Other causes are head and neck radiotherapy, in which amifostine is protective, dehydration, graft-versus-host disease, and mumps. Management includes saliva substitutes, sugar-free gum, meticulous dental care with topical fluoride, and muscarinic agonists pilocarpine or cevimeline.
Sources
- Harrison's Principles of Internal Medicine
- First Aid for the USMLE Step 1
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