The effects of topical anesthesia on oral burning in burning mouth syndrome.

Burning mouth syndrome (BMS) is an oral pain disorder of uncertain origin. Central or peripheral pain mechanisms may play a role in the oral burning of BMS. We tested the effect of a topical anesthetic (dyclonine HCl) on patients' intensity ratings for oral burning, taste dysgeusia and the taste of two chemical stimuli (1.0 M NaCl and 1.0 M sucrose). A total of 33 patients (9 male and 24 female, average age: 60 yr) are included in this analysis. The anesthetic reduced the perceptual intensity of both chemicals in these patients on four out of five postanesthesia trials (p < 0.01). The BMS cohort included 12 patients whose burning increased (p < 0.001), 14 patients whose burning did not change, and 7 patients whose burning decreased (p < 0.001) after anesthesia. Baseline dysgeusias (n = 13) decreased in intensity (p < 0.001) after anesthesia, suggesting BMS dysgeusia is related to the activation of peripheral taste mechanisms. The results also suggest that BMS oral burning may be a disorder of peripheral pain pathways in some patients.

Disorders in taste and smell.

Although many conditions and medications have been associated with chemosensory disturbances, data from major chemosensory clinical research centers support three major disorders as being causative: nasal and paranasal sinus disease (21%), post-upper respiratory tract viral infection (19%), and head trauma (14%). Despite extensive evaluation, 22% of patients do not demonstrate identifiable causation.

Differential effects of cocaine, alcohol, and nicotine dependence on olfactory evoked potentials.

Olfactory evoked potentials (OEP) were elicited by odorous and nonodorous stimuli in 50 adult subjects: 26 subjects with histories of either cocaine (n = 19) or alcohol (n = 7) dependence, 10 with histories of nicotine but no other drug dependence, 2 with clinical anosmia of peripheral origin, and 12 subjects without drug or olfactory disorders. The presentation of nonodorous stimuli (i.e. a nasal air puff) did not elicit OEP component amplitude and latency differences among the groups. However, the presentation of odorous stimuli elicited a significantly smaller P1 component in the cocaine-dependent and alcohol-dependent groups than in the normal control and nicotine-dependent groups. The P1 amplitude deficit in the cocaine-dependent group is consistent with case report data associating cocaine use with lesions of the peripheral and/or central olfactory apparatus.

Topical corticosteroid treatment of anosmia associated with nasal and sinus disease.

OBJECTIVE: To establish the efficacy of topical corticosteroid nasal spray treatment of severe olfactory loss associated with severe nasal and sinus disease. DESIGN: Efficacy before and after open-label trial of topical corticosteroid nasal spray used exclusively in the head-down-forward position. SETTING: Taste and smell clinic of a university teaching hospital and research facility. PATIENTS: Taste and smell clinic patients with anosmia or severe hyposmia associated with paranasal sinus disease and nasal polyposis including 39 of 45 patients recruited from 1988 to 1994 who completed the topical corticosteroid treatment course and returned for subsequent testing. INTERVENTION: At least 8 weeks of treatment with flunisolide (Nasalide), 2 sprays in each nostril twice a day, with concurrent antibiotic treatment of any bacterial infection. MAIN OUTCOME MEASURES: Subjective olfactory symptoms, objective olfactory function tests, and otolaryngological evaluation (including endoscopic examination). RESULTS: Olfactory scores significantly improved following treatment (P < .001); signs of nasal and sinus disease significantly decreased (P < .001); and 26 (66%) of the patients reported a subjective improvement in their sense of smell. CONCLUSION: Topical corticosteroid nasal spray administered in a head-down-forward position is an effective treatment of severe olfactory loss associated with severe nasal and sinus disease.

Effects of chlorhexidine on human taste perception.

Chlorhexidine gluconate at a dose used to control bacteria in the mouth has a reversible effect on taste perception. Taste-intensity ratings and taste-quality identification for concentration series of sucrose, sodium chloride, citric acid and quinine hydrochloride were obtained from 15 healthy humans. The participants rinsed with 0.12% chlorhexidine for 3 min twice a day. Each individual was tested 3 times: before the 4-day rinse period, 30 min after the final rinse, and 4 days after the rinse period. Chlorhexidine rinses reduced the perceptual intensity of sodium chloride and quinine hydrochloride, not sucrose or citric acid. No effects on taste perception were detected 4 days after the rinse period. The identification of sodium chloride as salty was seriously impaired by chlorhexidine but the identification of quinine hydrochloride as bitter was not affected. Specific sites of action of chlorhexidine on the taste epithelium are not known but its effects on salty taste may be related to its strong positive charge and its effect on bitter taste may be related to its amphiphilicity. Chlorhexidine has promise as a probe of taste transduction, as well as for the management of salty/bitter dysgeusias in humans.

Burning mouth syndrome: an update.

Though it has been the subject of much research, burning mouth syndrome--a chronic oral-facial pain condition that affects many U.S. adults--remains poorly understood. It has been associated with numerous oral and systemic conditions. Treatment options frequently include various medications. While patients with symptoms of BMS are more likely to seek care from physicians, dentists should be involved in the evaluation and management of these patients.

Diagnosis and management of taste disorders and burning mouth syndrome.

Clinically significant taste loss is less common than abnormal tastes (dysgeusias). Both may be caused by a previous viral upper respiratory infection, head trauma, iatrogenic causation (medication, irradiation, surgery), neurologic or psychiatric disorders, toxic chemical exposure, systemic conditions, xerostomia, severe nutritional deficiencies, and some oral or dental disorders. Beyond treatment targeted toward causative conditions, there is no proven intervention to either enhance taste acuity or abolish dysgeusia. The prevalence of oral burning sensations has been estimated at 2.6% for the general population. The burning typically increases throughout the day, and may be associated with taste alterations and psychological effects. Differential diagnoses considered include psychiatric illness, menopause, nutritional disorders, oral and dental conditions, and diabetes mellitus. Low doses of tricyclic antidepressants may be effective in some patients with idiopathic oral burning, and spontaneous remissions without intervention have been reported.

The sense of taste: neurobiology, aging, and medication effects.

The sense of taste is an oral chemical sense in mammals that is involved in the choice of foods. Initial transduction of taste stimuli occurs in taste buds, which are distributed in four discrete fields in the oral cavity. Medications can affect the taste buds and ion channels in taste-bud cell membranes involved in stimulus transduction. The sense of taste gradually declines with aging, with bitter taste most affected. Neural circuits that mediate taste in primates include cranial nerves VII, IX, and X, the solitary nucleus in the brain stem, the ventroposteromedial nucleus of the thalamus, and the insular-opercular cortex. The central taste pathways process taste information about sweet, salty, sour, and bitter stimuli serially and in parallel. Medications associated with "metallic" dysgeusia and taste losses affect the taste system via unknown mechanisms.

Allergic rhinitis and olfactory loss.

BACKGROUND: Allergic rhinitis is associated with reports of olfactory loss, but there are few formal investigations. Patients with diminished smell function frequently have nasal polyps or sinusitis, making it difficult to separate the impact of allergic rhinitis from the effects of these other problems. OBJECTIVE: The goals of this descriptive study were to establish the prevalence of positive skin tests in patients reporting rhinitis and olfactory deficiency, and to assess olfactory function and the results of skin testing in a patient group with chronic rhinitis but without concomitant sinusitis or nasal polyps. METHODS: Sixty-two patients reporting olfactory loss and chronic rhinitis were examined by history, physical examination, olfactory testing, skin testing with perennial and seasonal allergens, endoscopic rhinoscopy, and CT scan of the paranasal sinuses. RESULTS: Seventy-one percent of all the subjects had at least one positive skin test, 69% to a perennial allergen, and 58% to mite. Eighty-two percent of the 28 subjects with chronic rhinitis but no evidence of polyps or sinusitis had positive tests. The mean olfactory score for this rhinitis group was 4.35, consistent with moderate hyposmia. The mean olfactory score of 34 subjects with polyps and/or chronic sinusitis was 0.61, consistent with anosmia, and significantly lower (P < .001). Sixty-two percent of this group had positive skin tests. CONCLUSION: These subjects who experienced olfactory loss and rhinitis appeared to have a high prevalence of allergic rhinitis as suggested by the number of positive skin tests. Olfactory loss was observed in patients without polyps or sinusitis, which suggests that allergic processes may have affected olfactory function.

Olfactory loss and allergic rhinitis.

Olfactory loss is of importance for allergists to investigate in their patients, because if it is due to either allergic rhinitis or nonallergic rhinitis, it is potentially reversible. One should be sure to consider nasal polyposis and inflammation from chronic sinusitis, especially of the ethmoidal sinuses. Simple screening in the office can be achieved with an odor identification test of widely available substances as described above. Should there be no response to treatment or if the patient has a history of chronic sinusitis, recalcitrant nasal polyposis, or previous otolaryngologic procedures, further evaluation including rhinoscopy may be required. Recent olfactory loss in the absence of nasal symptoms and in the absence of abnormalities in the nasal cavity should suggest further investigation to look for a more central process. Morphologic investigation with electron microscopy of the olfactory epithelium and the superior nasal cavity is just beginning. The impact of inflammation in this area awaits investigation.