INTRODUCTION

Xerostomia is the subjective sensation of dry mouth, which may be caused by the reduction of salivary gland function. It is more common among the elderly and may cause oral and dental infections, dysphagia, speech disorders and taste alterations7. The most common causes of xerostomia are the use of drugs that reduce salivary flow (xerogenic drugs), autoimmune diseases and salivary gland radiation3,8,14. Saliva is very important for the maintenance of oral homeostasis. It has an antimicrobial activity, lubricates the oral mucosa, stabilizes pH, prevents demineralization of teeth7 and dissolves and transports the molecules necessary to taste sensation11,12.

Xerostomia may present variable severity, including cases in which the oral mucosa is relatively normal and cases in which there is complete absence of saliva, resulting in significant oral mucosa abnormalities and great discomfort to the patient. In addition to difficulties to masticate, swallow and speak because of lack of lubrication9, patients with xerostomia tend to avoid crunchy, sticky and dry foods10. They may also progress to tongue itching, halitosis and reduction of taste sensation1.

The purpose of the present study was to retrospectively analyze cases of xerostomia treated in our service, especially concerning the possible detected etiologies.

MATERIAL AND METHOD

We conducted a retrospective survey of all patients with xerostomia treated at the Ambulatory of Stomatology, Department of Otorhinolaryngology at Santa Casa de Misericórdia de São Paulo, between January 1997 and May 2000. The diagnosis of xerostomia was defined by the authors as the sensation of dry mouth reported by patients.

We studied 40 patients by analyzing the following parameters: gender, age, onset of symptomatology and first visit, symptoms referred by patients and possible detected etiologies.

RESULTS

Out of 40 studied patients, 38 (95%) were female and two (5%) were male subjects. Ages ranged from 16 to 81 years (mean age of 61.37 years). Distribution according to gender and age may be seen n Table 1.

The interval between onset of symptoms and the first visit to the Ambulatory of Stomatology ranged from one month to 12 years (mean of 2 years and 4 months). In addition to the sensation of dry mouth, reported by all studied patients, 20 patients (50%) complained of mouth etching and four (10%) had sore throat. Three patients (7.5%) progressed to dysphagia and six (15%) reported some type of food intolerance, such as difficulties to take spicy food (three patients), hard food (two patients), dry food (one patient), hot food (one patient), acid food (one patient), and sweet food (one patient). One patient reported intolerance to soft drinks. Two patients (5%) presented reduction of appetite and one of them complained of bitter taste in the mouth. Ocular dryness was associated with xerostomia in five cases (15%). Other less common complaints were thick saliva, recurrent edema in the parotid region, lip dryness, parestesia and tongue pruritus, each one reported by one patient. Six patients (15%) did not have any other symptom besides xerostomia.





The possible etiologies for each case of xerostomia were determined based on the data from anamnesis and posterior confirmation by laboratory tests and evaluation by other specialists. The known causes of xerostomia are shown in Chart 1. The use of drugs that reduced salivation was observed in 24 cases (60%), the most frequent cause of xerostomia in the studied group. Sjögren's syndrome accounted for symptoms in 11 patients (27.5%). Among the studied patients, 30% had hypertension, 10% had diabetes and 12.5% had dyslipidemia. In four female patients xerostomia was probably caused by hormonal factors, requiring hormone replacement therapy. Two patients (5%) had been submitted to radiotherapy in the head and neck region, two patients had thyroid pathology, two had psychiatric disorders and two had rheumatoid arthritis. Sialoadenitis was present in one single case and cerebral vascular accident in another.

DISCUSSION

More than 50% of the elderly have occasional complaints of xerostomia, whereas 10% to 25% present the symptom constantly12,15. In spite of that, xerostomia has been frequently neglected by health care professionals and even patients. This fact may be confirmed by the average 2 years and 4 months that took patients to come to a specialized center. The reasons behind that fact are complex. Some patients may believe that it is a normal symptom or a natural consequence of the aging process. Others are affected by a number of systemic complaints and tend to consider xerostomia as less important. The mean age of evaluated patients was 61.37 years, a fact in accordance with the data obtained from the literature that states that xerostomia is more prevalent among the elderly population. The only adolescent patient studied (16 years) had been submitted to radiotherapy to treat rhinopharynx lymphoepithelioma.

CHART 1 - Causes of xerostomia.

A. Influence of encephalic salivary nuclei
1. Emotional factors
2. Psychiatric disorders
3. Central nervous system tumors
4. Central action drugs (such as Levodopa and Morphine)
B. Influence on nervous transmission
1. Encephalitis and neuritis
2. Nervous trauma
3. Cerebral vascular accident
4. Neurosurgical procedures
C. Salivary glands diseases
1. Aplasia
2. Surgical excision
3. Obstruction and sialoadenitis
4. Sjögren's syndrome
5. Sarcoidosis
6. Radiation
7. Salivary gland tumors
8. Heerfordt's syndrome (uveoparotiditis)
D. Hydro-electrolytic balance disorders
1. Dehydration
2. Diabetes
3. Uremia
4. Hypertension
5. Thyroid pathologies
6. Folic acid deficiency
7. Hormonal dysfunction
8. Parkinson's disease
9. Therapeutic and Illegal Drugs
E. Physiological changes
1. Aging
2. Menopause

From: James C. Burns Xerostomia - Va Dent J. 68(3):34-9, 1991.

Various factors are described in the literature as the causes of xerostomia. Among the most frequent ones we may list the use of drugs that reduce salivary flow, autoimmune diseases such as Sjögren's syndrome and head and neck radiotherapy8,14. We found the same distribution in our population, except for radiotherapy, which was present in the history of only 5% of the cases.

Every year, approximately 40,000 patients are submitted to radiotherapy to treat head and neck tumors in the United States. Relatively low doses of radiation are enough to reduce salivary flow, sometimes permanently8. Therefore, the low percentage of irradiated patients in our sample could mean that these people are not being appropriately informed about the therapeutic possibilities available for xerostomia.

The high prevalence of hypertension, diabetes mellitus, dyslipidemia and hormonal alterations in the studied group was obviously due to the old age range of patients. In some situations, these alterations are not the main factor responsible for xerostomia, but they definitely contribute to its occurrence4,5,16.

The reduction of salivary flow is not a natural consequence of aging process. Most of the times, it results from conditions that are more common among middle-aged and elderly people. Most of these conditions are iatrogenic, such as the use of medication and radiotherapy2. It is estimated that in the US the elderly uses 30% of all prescribed medication12. They frequently have systemic diseases, including autoimmune diseases, which require further use of drugs or cause xerostomia themselves. In addition, elderly people are less resistant to stress and they have a limited physiological reserve, which makes them particularly prone to the harmful consequences of xerostomia. We observed in our study that 15% of the patients presented intolerance to some kind of food, 7.5% had dysphagia and 5% complained of reduction of taste sensation. Studies suggested that problems like these could contribute to nutritional deficits in the elderly10,12.

According to the literature, women have more xerostomia than men6,13, a fact confirmed by the present study. The possible reason for that is that post-menopause women, between 50 and 65 years of age, tend to have a reduction in salivary flow; besides, female salivary glands are smaller than males'13,17.

CONCLUSION

The present study concluded that xerostomia is the most common complaint among middle-aged and elderly women. It is not a valued symptom by a large proportion of the patients, which sometimes takes long to search for specialized treatment. Low prevalence of irradiated patients in our sample made us believe that xerostomia is also underestimated by health care professionals who do not refer the patients to ENT assessment. Xerostomia should be carefully investigated in risk groups because it may contribute, among other complications, to nutritional deficits in patients who already have a limited physiological reserve. The most common causes of xerostomia in our center were use of drugs that reduce salivary flow and Sjögren's syndrome.

REFERENCES

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* Postgraduate, Faculdade de Ciências Médicas da Santa Casa de São Paulo.
** Joint Professor, Faculdade de Ciências Médicas da Santa Casa de São Paulo.

Study presented as poster at 35° Congresso Brasileiro de Otorrinolaringologia, in Natal/RN, on October 18, 2000.
Address correspondence to: Daniella Belotto Pupo - Rua Itambé, 367 - Apto. 72A - Higienópolis - São Paulo /SP - Tel: (55 11) 257-7829 - Fax: (55 11) 256-4062
Article submitted on November 20, 2000. Article accepted on January 15, 2001.