MedicineToday 2014; 15(4): 30-37 PEER REVIEWED FEATURE 2 CPD POINTS An approach to the patient with a dry mouth Key points • The subjective complaint of ELHAM AFLAKI MD; TAHEREH ERFANI MD; NICHOLAS MANOLIOS MB BS(Hons), PhD, MD, FRACP, FRCPA; xerostomia needs to be MARK SCHIFTER FFD, RCSI(Oral Med), FRACDS(Oral Med) differentiated from true salivary hypofunction. Dry mouth is a common and disabling problem. After exclusion of treatable • Salivary hypofunction can significantly reduce quality causes, treatment is symptomatic to prevent the consequences of salivary of life through its adverse hypofunction, such as tooth decay and infection of the oral mucosa. effects on taste, mastication, swallowing, cleansing of the erostomia, or the subjective feeling of neuropathic-induced orofacial dysaesthesia) mouth, killing of microbes a dry mouth, is a common complaint. and psychological and psychiatric disorders, and speech. It is often a consequence of salivary such as anxiety and depression. • Salivary hypofunction is a hypofunction (hyposalivation), in substantive risk factor for X which there is objective evidence of reduced NORMAL SALIVA PRODUCTION dental caries, oral mucosal salivary output or qualitative changes in saliva. Under normal physiological conditions, the disease and infection, Typically, patients complain of oral dryness salivary glands produce 1000 to 1500 mL of particularly oral candidiasis. only when salivary secretion is reduced by more saliva daily as an ultrafiltrate from the circu- • Patients should be than half.1 As saliva has a crucial role in taste lating plasma. Therefore, simple dehydration investigated for contributory perception, mastication, swallowing, cleansing reduces saliva production. The parotid glands and underlying causes, of the mouth, killing of microbes and speech, are the major source of serous saliva (60 to 65% which include drugs and abnormalities in saliva production can signif- of total saliva volume), producing the stimu- rheumatological diseases. icantly affect quality of life. lated salivary flow seen with mastication. • Patients with salivary Xerostomia also occurs in patients with no Serous saliva is also produced during rest by hypofunction can be treated measurable decrease in saliva production. the submandibular glands. This unstimulated with artificial saliva, Causes of this ‘subjective’ xerostomia include salivary flow is essential for maintenance of moisturising gels, sugar-free burning mouth syndrome (better termed oral and dental health. Mucinous saliva is lozenges or gums and muscarinic drugs Dr Aflaki was a Visiting Academic of the University of Sydney (currently Assistant Professor of Rheumatology, Shiraz (cevimeline, pilocarpine). University of Medical Sciences, Shiraz, Iran) and Dr Erfani was a Basic Physician Trainee Registrar in the Department • Attention to maintaining and of Rheumatology, Westmead Hospital, Sydney (currently a Clinical Research Fellow in the Department of Rheumatology, improving oral health is Royal North Shore Hospital, Sydney). Professor Manolios is Head of the Department of Rheumatology, Westmead important, and treatment of Hospital, Sydney. Dr Schifter is Head of the Department of Oral Medicine, Oral Pathology and Special Needs consequent dental Copyrightcaries is _LayoutDentistry, 1 17/01/12 Westmead 1:43 Hospital, PM Page Sydney; 4 Clinical Associate Professor in the Faculty of Dentistry, the University of essential. Sydney; and a Consultant in Oral Medicine at the Skin and Cancer Foundation Australia, Sydney, NSW. © JACKIE HEDA 30 MedicineToday x APRIL 2014, VOLUME 15, NUMBER 4 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. produced primarily by minor salivary of the tongue glands. The quality of saliva depends on • a feeling of xerostomia or more 1. CAUSES OF XEROSTOMIA5 the rate of flow. Resting saliva is viscous commonly a sense of an unpleasant and acidic, whereas stimulated saliva is alteration in the texture and quality Psychological and psychiatric hypotonic and alkaline. of the saliva disorders • frequently, dysgeusia. • Anxiety SYMPTOMS OF A DRY MOUTH Best described as an orofacial dysaes- • Depression Several studies have reported discordance thesia, with an element of neuropathic- Burning mouth syndrome between patients’ complaints of xerostomia induced sensory disturbance and associated Hyposalivation and hyposalivation, with a limited associ- psychogenic factors, burning mouth syn- • Medications and other drugs ation observed between perceived dry drome warrants specialist evaluation, for • Rheumatological diseases mouth and decreased salivary flow.2,3 A example by a specialist in oral medicine. − Sjögren’s syndrome South Australian study reported that − Rheumatoid arthritis although dry mouth and hyposalivation Hyposalivation − Systemic lupus erythematosus had similar prevalence estimates (about Drugs − Scleroderma 20%), the two conditions occurred together Hyposalivation is a common side effect of • Immune-mediated conditions in only 6% of participants.4 many medications (see Box 2).6 Most of − Sarcoidosis Symptoms and signs that may accom- these medications affect the neural regu- − Primary biliary cirrhosis pany hyposalivation include: lation of the saliva, which is controlled by • Endocrine disorders • increased thirst and the need to the autonomic nervous system. The sym- − Diabetes mellitus constantly sip or drink water pathetic arm with adrenergic receptors − Diabetes insipidus • difficulty in eating and swallowing inhibits saliva production, and the para- • Radiotherapy (> 50 Gy) encompassing dry foods sympathetic arm with cholinergic (specif- one or more major salivary glands, • difficulty in wearing dentures ically muscarinic) receptors stimulates especially the parotid glands • an increased rate of dental caries saliva production. Many drugs are innately • Metabolic and nutritional disorders • halitosis anticholinergic, thereby limiting or reduc- − Dehydration • a hoarse voice or the inability to ing saliva production. Some drugs and • Infections (viral) speak continuously common beverages such as caffeine and − HIV infection • a constantly sore mouth or throat alcohol also have a diuretic effect, depleting − Hepatitis C • oral candidiasis. the body’s water reserves and so reducing − Cytomegalovirus (and other herpes Other symptoms that suggest sub jective saliva production. infections) xerostomia in the absence of hyposalivation • Renal disease (end-stage) include: Sjögren’s syndrome • Congenital • a burning sensation of the tongue Sjögren’s syndrome (autoimmune exocrin- − Prader–Willi syndrome • a feeling of altered quality and opathy) is a chronic autoimmune disorder − Congenital rubella viscosity of the saliva characterised by lymphocytic infiltration − Lacrimo-auriculo-dento-digital • altered sense of taste (dysgeusia). of all exocrine glands, with destruction of (LADD) syndrome the acini. It is more common in middle- − Complete agenesis of salivary glands CAUSES OF A DRY MOUTH aged women, particularly those of north- Causes of xerostomia are summarised in ern European ancestry. Sjögren’s syndrome Box 1.5 was previously classified as primary or as seen in two-thirds of patients with primary secondary to other autoimmune diseases, Sjögren’s syndrome but is not common Burning mouth syndrome particularly the mixed connective tissue when the syndrome is associated with other A proportion of patients with subjective diseases, rheumatoid arthritis, systemic immune-mediated conditions. Systemic xerostomia have burning mouth syn- lupus erythematosus (SLE) and manifestations are seen in one-third of drome. This poorly understood syndrome scleroderma. patients and include arthralgia, arthritis, presents in the absence of any identifiable The major presenting complaint is Raynaud’s phenomenon and vasculitis. pathology of the oral mucosa or of saliva increasing dryness of the eyes and mouth, Lymphoma (particularly extranodal, production and quantity. It has a typical but the nose, throat, trachea and vagina low-grade marginal zone B cell lymphoma) triad of symptoms:Copyright _Layout 1 17/01/12may 1:43 also PM be Pageaffected. 4 Enlargement of the is a known complication of Sjögren’s • a burning sensation, particularly parotid or other major salivary glands is syndrome.7 MedicineToday x APRIL 2014, VOLUME 15, NUMBER 4 31 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. APPROACH TO DRY MOUTH CONTINUED Endocrine disorders with a history of radiotherapy or systemic 2. DRUGS THAT COMMONLY The most common endocrine disorders conditions associated with hyposalivation CAUSE SALIVARY HYPOFUNCTION6 that can cause dry mouth include diabetes may indicate progression of the underlying mellitus, hypothyroidism and diabetes disease and the need for more aggressive • Alpha blockers: clonidine, prazosin insipidus. Diabetes mellitus can have two intervention or treatment of the conse- • Angiotensin–converting enzyme major adverse effects on saliva production: quences of salivary hypofunction. inhibitors: captopril, lisinopril diabetes-induced neuropathy of the para- • Anticholinergics: atropine, hyoscine, sympathetic nervous supply results in Physical examination tolterodine reduced saliva and, indirectly, the diuresis Before specifically examining the mouth • Antihistamines: loratadine, fexofenadine, associated with diabetes (also seen with for signs of hyposalivation, assess the diphenhydramine diabetes insipidus) can also impair