Burning mouth syndrome (BMS): controlled open trial of the efficacy of alpha-lipoic acid (thioctic acid) on symptomatology

Burning mouth syndrome: Clinical presentation, diagnosis and treatment

Burning mouth syndrome is an oral dysaesthesia presenting as a burning sensation of the tongue and less frequently other oral and peri-oral sites. There may be other coincident symptoms and signs, but the defining feature is the absence of any obvious organic cause. Because of this the condition frequently remains unrecognized for extended periods with a variable progression of symptoms. The current paper describes the complex presentation of burning mouth syndrome with the major aim of increasing recognition.

Life-threatening disorders of mucous membranes

Oral mucosa is one of the first barriers to the outside world which encounters various antigens, microorganisms and physical agents. Numerous oral pathologies challenge the dermatologists. Some may be the first sign of an underlying immunosuppression, while others are the inevitable serious outcomes of long-lasting mucosal disease. The differential diagnosis is crucial in terms of prompt and effective treatment.

Interventions for the treatment of burning mouth syndrome

BACKGROUND

The complaint of a burning sensation in the mouth can be said to be a symptom of other disease or a syndrome in its own right of unknown aetiology. In patients where no underlying dental or medical causes are identified and no oral signs are found, the term burning mouth syndrome (BMS) should be used. The prominent feature is the symptom of burning pain which can be localised just to the tongue and/or lips but can be more widespread and involve the whole of the oral cavity. Reported prevalence rates in general populations vary from 0.7% to 15%. Many of these patients show evidence of anxiety, depression and personality disorders.

OBJECTIVES

The objectives of this review are to determine the effectiveness and safety of any intervention versus placebo for relief of symptoms and improvement in quality of life and to assess the quality of the studies.

SEARCH STRATEGY

We searched the Cochrane Oral Health Group Trials Register (20 October 2004), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2004), MEDLINE (January 1966 to October 2004), EMBASE (January 1980 to October). Clinical Evidence Issue No. 10 2004, conference proceedings and bibliographies of identified publications were searched to identify the relevant literature, irrespective of language of publication.

SELECTION CRITERIA

Studies were selected if they met the following criteria: study design - randomised controlled trials (RCTs) and controlled clinical trials (CCTs) which compared a placebo against one or more treatments; participants - patients with burning mouth syndrome, that is, oral mucosal pain with no dental or medical cause for such symptoms; interventions - all treatments that were evaluated in placebo-controlled trials; primary outcome - relief of burning/discomfort.

DATA COLLECTION AND ANALYSIS

Articles were screened independently by two reviewers to confirm eligibility and extract data. The reviewers were not blinded to the identity of the studies. The quality of the included trials was assessed independently by two reviewers, with particular attention given to allocation concealment, blinding and the handling of withdrawals and drop outs. Due to both clinical and statistical heterogeneity statistical pooling of the data was inappropriate.

MAIN RESULTS

Nine trials were included in the review. The interventions examined were antidepressants (two trials), cognitive behavioural therapy (one trial), analgesics (one trial), hormone replacement therapy (one trial), alpha-lipoic acid (three trials) and anticonvulsants (one trial). Diagnostic criteria were not always clearly reported. Out of the nine trials included in the review, only three interventions demonstrated a reduction in BMS symptoms: alpha-lipoic acid (three trials), the anticonvulsant clonazepam (one trial) and cognitive behavioural therapy (one trial). Only two of these studies reported using blind outcome assessment. Although none of the other treatments examined in the included studies demonstrated a significant reduction in BMS symptoms, this may be due to methodological flaws in the trial design, or small sample size, rather than a true lack of effect.

AUTHORS' CONCLUSIONS

Given the chronic nature of BMS, the need to identify an effective mode of treatment for sufferers is vital. However, there is little research evidence that provides clear guidance for those treating patients with BMS. Further trials, of high methodological quality, need to be undertaken in order to establish effective forms of treatment for patients suffering from BMS.

Burning mouth syndrome: the efficacy of lipoic acid on subgroups

OBJECTIVE

We have examined the effect of alpha-lipoic acid (ALA, tioctic acid; Tiobec), a free radical scavenger, on the discomfort of burning mouth syndrome (BMS) in patients who had used tranquillizers previously, compared with those who had not.

METHODS

In this study we gave lipoic acid for 2 months to two groups of 20 BMS patients, one of which had previously been treated with tranquillizers.

RESULTS

The results showed greater effectiveness of lipoic acid in BMS patients who had not previously used tranquillizers.

CONCLUSIONS

The patients with BMS who had previously been treated with tranquillizers responded poorly to therapy with lipoic acid compared with those who had not received previous psychotropic therapy.

Biochemical analysis of saliva and taste acuity evaluation in patients with burning mouth syndrome, xerostomia and/or gustatory disturbances

OBJECTIVE

In the current study, we performed taste and salivary analysis on patients suffering from burning mouth syndrome and xerostomia or taste disturbances.

STUDY DESIGN

A total of 180 patients who complained of idiopathic burning mouth syndrome (BMS) and taste aberrations and/or xerostomia that may accompany BMS were evaluated. These patients were compared with 90 healthy, age- and sex-matched controls. Salivary flow rate, biochemical and immunological analysis and taste acuity by the forced-choice drop technique were performed for all subjects. These analyses were found to be conclusive in distinguishing controls from patients with complaints.

RESULTS

The great similarity of both salivary and taste analysis in the BMS, taste aberration and xerostomia groups, which were significantly different from the results obtained in the control group, was found to be the most striking result. Higher salivary concentrations in the experimental group were consistent with a lower saliva (water) flow rate.

CONCLUSION

An oral neuropathy and/or neurological transduction interruption induced by salivary compositional alterations is suggested as the possible aetiology for the complaints. This report may add an important objective diagnostic tool to the clinician treating these patients.

Sialochemical and gustatory analysis in patients with oral sensory complaints

Our objective was to perform concomitant taste and salivary analyses in subjects with oral sensory complaints (OSC), including burning mouth syndrome (BMS), idiopathic taste aberrations, and xerostomia without established etiology, to attempt to find a possible explanation for the mechanism underlying those complaints. BMS is a disorder characterized by a painful burning or scalding sensation in clinically normal and healthy oral mucosa. Taste and salivary analyses were performed on 163 subjects with OSC who complained of BMS, taste aberration, or xerostomia, alone or in combination. These subjects were compared with 84 healthy, age- and sex-matched control subjects. The salivary and taste analyses were found to be helpful in distinguishing control subjects from complaining subjects. The most striking result found was the great similarity of both salivary and taste analyses in the BMS, taste aberration, and xerostomia groups, which were significantly different from the results obtained in the control group. An oral neuropathy or neurologic transduction interruption induced by salivary compositional alterations is suggested as the possible etiology for the complaints. This report might add an important objective diagnostic tool to the clinician treating such patients.

PERSPECTIVE

The merit of the current study stems from the fact that it suggests for the first time a salivary-related local neuropathic mechanism for oral sensorial complaints. This may be of paramount importance, both with respect to the biological background of these complaints and to the possible therapeutic modalities that might be offered to suffering patients.

[Mouth dryness and burning sensation of the oral mucosa: causes and possibilities for treatment]

Both sets of complaints, mouth dryness and a burning sensation of the oral mucosa, can have a variety of causes. Local and regional as well as systemic causes can be responsible for burning mouth syndrome. Diseases of the oral mucosa can have genetic, inflammatory, or neoplastic origins. Autoimmune diseases and allergies as well as different afflictions relating to internal medicine can be accompanied by a burning sensation in the oral mucosa. Neurological and psychiatric illnesses must be clarified during interdisciplinary diagnostics in order to identify idiopathic forms. The causes of mouth dryness are similarly complex. In addition to inadequate fluid intake, particularly in elderly patients, drug side effects or systemic diseases are frequently also responsible. Treatment is directed at the underlying disease; in ambiguous cases, symptomatic therapy can provide relief for medical complaints.

Idiopathic dysgeusia; an open trial of alpha lipoic acid (ALA) therapy

We selected two homogenous groups, each of 22 patients with idiopathic dysgeusia, an altered perception of taste, matched for age and sex, for an open trial of alpha lipoic acid compared with placebo. The 22 patients in the study group were treated with alpha lipoic acid for 2 months. The 22 patients in the control group were treated for 2 months with carboxymethylcellulose. The latter group was then treated with alpha lipoic acid for 2 months. The results showed significant symptomatic improvements compared with placebo, in both groups of patients with dysgeusia treated with alpha lipoic acid, suggesting that idiopathic dysgeusia may be a neuropathy comparable to the burning mouth syndrome.

Burning mouth syndrome (BMS): double blind controlled study of alpha-lipoic acid (thioctic acid) therapy

BACKGROUND

Burning mouth syndrome (BMS) has features of a neuropathy and could be related to the production of the toxic free radicals that are released in stress situations. Alpha-lipoic acid is an antioxidant able to increase the levels of intracellular glutathione and eliminate free radicals. This study aimed to examine the effectiveness of alpha-lipoic acid in the therapy of BMS.

METHOD

This was a double blind, controlled study conducted for two months on 60 patients with constant BMS. Comparing alpha-lipoic acid (test) with cellulose starch (placebo), there was no laboratory evidence of deficiencies in iron, vitamins or thyroid function and no hyperglycaemia.

RESULTS AND CONCLUSION

Following treatment with alpha-lipoic acid, there was a significant symptomatic improvement, compared with placebo, with the majority showing at least some improvement after 2 months, thus supporting the hypothesis that burning mouth syndrome is a neuropathy. This improvement was maintained in over 70% of patients at the 1 year follow-up.

Interventions for the treatment of burning mouth syndrome

BACKGROUND

The complaint of a burning sensation in the mouth can be said to be a symptom of other disease or a syndrome in its own right of unknown aetiology. In patients where no underlying dental or medical causes are identified and no oral signs are found, the term burning mouth syndrome (BMS) should be used. The prominent feature is the symptom of burning pain which can be localised just to the tongue and/or lips but can be more widespread and involve the whole of the oral cavity. Reported prevalence rates in general populations vary from 0.7% to 15%. Many of these patients show evidence of anxiety, depression and personality disorders.

OBJECTIVES

The objectives of this review are to determine the effectiveness and safety of any intervention versus placebo for relief of symptoms and improvement in quality of life and to assess the quality of the studies.

SEARCH STRATEGY

Electronic databases (The Cochrane Library, the Cochrane Oral Health Group's Specialised Register, MEDLINE, EMBASE), Clinical Evidence Issue No. 3, conference proceedings and bibliographies of identified publications were searched to identify the relevant literature, irrespective of language of publication.

SELECTION CRITERIA

Studies were selected if they met the following criteria: study design - randomised controlled trials (RCTs) and controlled clinical trials (CCTs) which compared a placebo against one or more treatments; participants - patients with burning mouth syndrome, that is, oral mucosal pain with no dental or medical cause for such symptoms; interventions - all treatments that were evaluated in placebo-controlled trials; primary outcome - relief of burning/discomfort

DATA COLLECTION AND ANALYSIS

Articles were screened independently by two reviewers to confirm eligibility and extract data. The reviewers were not blinded to the identity of the studies. The quality of the included trials was assessed independently by two reviewers, with particular attention given to allocation concealment, blinding and the handling of withdrawals and drop-outs. Due to differences in patient type, treatment and outcome measures, statistical pooling of the data was inappropriate.

MAIN RESULTS

Six trials were included in the review. The interventions examined were antidepressants (two trials), cognitive behavioural therapy (one trial), analgesics (one trial), hormone replacement therapy (one trial) and vitamin complexes (one trial). The participants included in the six identified trials reported suffering from BMS from six months to 20 years. Diagnostic criteria were not always clearly reported. Out of the six trials included in the review, only two interventions demonstrated a reduction in BMS symptoms; vitamin complexes and cognitive behavioural therapy. Neither of these studies reported using blind outcome assessment. Although none of the other treatments examined in the included studies demonstrated a significant reduction in BMS symptoms, this may be due to methodological flaws in the trial design, or small sample size, rather than a true lack of effect.

REVIEWER'S CONCLUSIONS

Given the chronic nature of BMS, the need to identify an effective mode of treatment for sufferers is vital. However, there is little research evidence that provides clear guidance for those treating patients with BMS. Further trials, of high methodological quality, need to be undertaken in order to establish effective forms of treatment for patients suffering from BMS.