Saliva has a crucial role in the maintenance of oropharyngeal health.
Dry mouth (xerostomia) or salivary hypofunction is more common in older patients. It can result in impairment of masticatory effectiveness, host defences and speech, which can potentially result in a reduction in quality of life.
It is estimated that 30 per cent of the population over the age of 65 have some degree of salivary hypofunction.1
There are many causes for dry mouth (see box).
Features and diagnosis
Aside from the obvious feature of a reduction in the amount of saliva production, several other features are often apparent in xerostomia cases (see box).
Some of these features may also lead to problems with the aerodigestive tract. Indigestion may occur and even colonisation of the lungs with Gram-negative anaerobes resulting in an increased susceptibility to aspiration pneumonia.2
Unstimulated normal salivary flow is approximately 0.3ml/min. This rate can drop to less than 0.1ml/min in those with xerostomia.
Stimulated salivary flow can be as much as 1-2ml/min. Patients with xerostomia may have a stimulated flow rate lower than 0.5ml/min.
Blood tests to rule out a systemic cause may be considered. These include an FBC, U&Es, LFTs, ferritin, folate, B12, glucose and rheumatoid factor.
Specific tests would also include antinuclear antibody (ANA) and serum angiotensin converting enzyme, and extractable nuclear antigen antibodies (SSA and SSB). Antibodies to extractable nuclear antigens are important markers for primary or secondary Sjogren's syndrome.
Treatment of dry mouth depends on the diagnosis. This often involves a multidisciplinary team of clinicians.
General advice should consider things patients may have overlooked and is vital irrespective of the cause. Mouth spray or lozenges can offer relief for some patients (see box below).
Pilocarpine helps produce saliva via a parasympathetic stimulation pathway and thus can also produce parasympathetic-induced side-effects, for example, sweating, dizziness and blurred vision. A low dose is recommended initially.
Pilocarpine can work well when used in addition to the general measures outlined above.
- Mr Shah is a specialist oral surgeon at Southend Hospital, Essex.
1. Ship JA, Pillemer SR, Baum BJ. Xerostomia and the geriatric patient. J Am Geriatric Soc 2002; 50(3): 535-43.
2. Loesche WJ, Bromberg J, Terpenning MS et al. Xerostomia, xerogenic medications and food avoidances in selected geriatric groups. J Am Geriatric Soc 1995; 43(4): 401-7.