The Prevalence of Burning Mouth Syndrome: A Population-Based Study

Abstract

Background

Burning mouth syndrome (BMS) is defined as symptoms of persistent burning in the mouth without objective findings accounting for the symptoms.

Objectives

To calculate the point prevalence of BMS in Olmsted County, Minnesota, on December 31, 2010.

Methods

The Rochester Epidemiology Project (REP) medical records linkage system was used to identify BMS cases diagnosed or potentially diagnosed before December 31, 2009. Inclusion criteria were subjective oral discomfort, normal oral examination, and documented BMS diagnosis by a REP physician.

Results

In total, 149 BMS cases were confirmed, representing age- and sex-adjusted point prevalence of BMS in Olmsted County of 0.11%, or 105.6 (95% CI, 88.6–122.6) per 100,000 persons. Age-adjusted prevalence in women was significantly higher than men: 168.6 (95% CI, 139.0–198.2) vs 35.9 (95% CI, 21.4–50.3) per 100,000 persons (P<.001). The highest prevalence was in women aged 70 through 79 years (527.9 per 100,000 persons). Mean (SD) age at BMS diagnosis was 59.4 (15.1) years (range, 25–90 years).

Conclusions

To our knowledge, we provide the first report of population-based BMS prevalence. The data show that BMS most commonly affects women older than 50 years, and when defined through diagnostic criteria, it is less prevalent than described previously.

Introduction

Burning mouth syndrome (BMS) is the persistent burning sensation of the mouth in the absence of objective signs. Published prevalence data are sparse and highly variable, ranging from 1% to 40% (Table 1). Our group has recently described the incidence of BMS, but to our knowledge, no population-based data exist on BMS prevalence. The aim of this study was to determine the population-based prevalence of BMS in Olmsted County, Minnesota.

Table 1.

Epidemiologic Studies of Burning Mouth Syndrome

Reference	Prevalence, %	Study Method
Kohorst et al, present reporta	0.11, total; 0.04, male; 0.17, female	Population-based retrospective review of Olmsted County, Minnesota
Netto et al2	1.0	Retrospective review of 3,243 patients referred to oral pathology department at a single hospital in Brazil over 7 y
Suzuki et al3	3.0, total; 2.8, male; 3.2, female	Questionnaire of 2,599 dental patients at 2 offices in Japan
Rabiei et al4	16.9	Cross-sectional study of 216 nursing-home residents in Iran
Moore et al5	2.1	Cross-sectional study of 216 volunteer participants in Pittsburgh, Pennsylvania
Brailo et al6	5.4	Retrospective review of 1,399 patients referred to oral medicine department in Croatia in 2001
Bergdahl and Bergdahl7	3.7, total; 1.6, male; 5.5, female	Survey of 1,427 Swedish volunteers (age, 20–69 y)
Riley et al8	1.7	Telephone survey of 1,636 volunteers from North Florida (age, >65 y)
Hakeberg et al9	4.6	1,017 middle-aged and elderly women in Sweden
Thorstensson and Hugoson10	3.4	Survey of 533 Swedish volunteers (age, 20–70 y)
Tammiala-Salonen et al11	14.8	431 Finnish volunteers

^aPoint prevalence on December 31, 2010.

Adapted from Kohorst JJ, Bruce AJ, Torgerson RR, et al. A population-based study of the incidence of burning mouth syndrome. Mayo Clin Proc 2014; pii: 1–8. [Epub ahead of print] Used with permission.

Materials and Methods

After approval by the Mayo Clinic and Olmsted Medical Center institutional review boards, the REP medical records linkage system was used to identify cases of BMS. Since 1966, the REP has collected patient records of Olmsted County residents with 98% represented by the REP.¹² The county is socioeconomically and demographically similar to the US white population. ^19–14

The REP was screened for patients with a BMS diagnosis between January 1, 2000 and December 31, 2009. Inclusion criteria were subjective oral discomfort, a normal oral examination, and a documented BMS diagnosis by a REP physician. Exclusion criteria was any objective abnormality in the mouth that would account for oral burning symptoms.

The earliest BMS entry was retained for any duplicate entries. All demographic and symptom-specific data was retrospectively collected from the medical record. Intensity of pain was abstracted from either a 0-to-10 numeric pain scale or a subjective description of mild, moderate, or severe pain.

Data were analyzed with SAS version 9.3 software (SAS Institute Inc). Point prevalence of BMS in Olmsted County was calculated assuming the entire population of Olmsted County for 2010 was at risk. The prevalence estimates were age- and sex-adjusted to the population distribution of US whites in 2010. Age- and sex-specific denominator values used the total Olmsted County population at the 2010 census. The 95% CIs for prevalence were constructed assuming Poisson error distribution. Difference in prevalence by sex was assessed with a Poisson regression to control for age. Observations used in the regression were crude prevalence counts by 10-year age-groups and sex, which were offset by the natural logarithm of the number of persons in each observation. Overdispersion was accounted for through estimation of the dispersion parameter, which was used to adjust the variance of the parameter estimates.¹⁵ The calculated P value was 2-sided.

Results

A total of 546 patients were identified from the Rochester Epidemiology Project (REP) as having a potential BMS diagnosis. Patients were excluded for the following characteristics: 24, lack of research authorization; 26, nonresident status; and 74, death before December 31, 2010. Of the remaining 413 patients, 149 met the study inclusion criteria, while the remainder had objective findings on oral examination (n=4) or did not receive a diagnosis of BMS by an REP physician (n=260).

The 149 prevalent cases involved 125 women (83.9%) and 24 men (16.1%). Most were white (92.6%) and never smokers (62.6%). Mean (SD) age at BMS diagnosis was 59.4 (15.1) years (range, 25–90 years). The tongue, alone or in conjunction with other areas, was a site of burning mouth symptoms in 81.9% of the 149 prevalent cases. Symptom intensity was frequently described as mild (41.6%) with bilateral (89.3%) and midline (73.2%) localization. Symptoms typically occurred in a continuous pattern (86.6%) throughout the day (68.5%). Parageusia was reported in 10.7% of cases and xerostomia in 28.2%.

Age- and sex-adjusted point prevalence of BMS in Olmsted County was 0.11% or 105.6 (95% CI, 88.6–122.6) per 100,000 persons (Table 2). Total prevalence was highest in the group aged 70 through 79 years (0.34%). The age-adjusted prevalence in women was significantly higher than in men: 168.6 (95% CI, 139.0–198.2) vs 35.9 (95% CI, 21.4–50.3) per 100,000 persons (P<.001). The highest prevalence was in women aged 70 through 79 years (527.9 per 100,000 persons); the highest prevalence in men was in this age-group (204.9 per 100,000 persons).

Table 2.

Point Prevalence of Burning Mouth Syndrome per 100,000 Persons by Age and Sex in Olmsted County, Minnesota, on December 31, 2010

	Women (n=125)		Men (n=24)		Both Sexes (N=149)
Age-group, y	No. of Cases	Proportion per 100,000 Persons (95% CI)	No. of Cases	Proportion per 100,000 Persons (95% CI)	No. of Cases	Proportion per 100,000 Persons (95% CI)
<50	31	62.7 (42.6–89.0)	9	18.2 (8.3–34.5)	40	40.4 (28.9–55.1)
50–59	29	277.5 (185.8–398.5)	4	40.7 (11.1–104.1)	33	162.7 (112.0–228.4)
60–69	33	507.1 (349.1–712.2)	2	34.5 (4.2–124.6)	35	284.5 (198.1–395.6)
70–79	21	527.9 (326.8–807.0)	7	204.9 (82.4–422.2)	28	378.7 (251.6–547.3)
≥80	11	326.6 (163.0–584.4)	2	101.5 (12.3–366.5)	13	243.5 (129.6–416.4)
Total (95% CI)		169.5 (141.1–201.9)a		34.0 (21.8–50.7)a		103.3 (87.4–121.3)b

Prevalence per 100,000 persons is directly age- and sex-adjusted to the population structure of the US total population in 2010.

Discussion

Demographic and symptom data in our study are comparable with prior BMS prevalence studies and BMS was again found most commonly in postmenopausal women.⁷. However, the present study shows a lower BMS prevalence than previously reported (Table 1). This is likely owing to the strict BMS definition used. Many definitions of BMS have been used in prior prevalence studies, but few would fulfill the stringent criteria applied in this study (persistent symptoms of oral discomfort, no findings on oral examination, exclusion of other causes of oral burning). Past studies have retained patients with subjective oral burning as the only inclusion criterion^3,5 or abnormal findings on oral examination,¹¹ which may account for the higher reported prevalence in these studies. Additionally our study observed that BMS prevalence suddenly increases after age 70 in males: why this should be the case is unclear.

This study has multiple limitations. Factors that could contribute to the sensation of oral burning, including medication intake, nutritional status, and both local and systemic diseases, were not analyzed. Pain intensity was not consistently documented in the medical records, but rather subjectively described. Finally, the use of stringent BMS criteria is both a strength and a limitation. The strength is that these data offer a specific representation of the BMS population with persistent oral symptoms and thorough exclusion of other possible etiologic factors. The limitation is that patients with burning mouth symptoms who did not meet these diagnostic criteria were excluded.

To our knowledge, these are the first-reported population-based prevalence data for BMS. The findings provide a reliable contribution to the nascent BMS epidemiology literature. The data show that BMS most commonly affects women older than 50 years, and that when defined through diagnostic criteria, BMS is less prevalent than previously suspected with a prevalence of approximately 1:1,000 patients. Further studies should evaluate the impact of medication intake, nutritional status, and the presence of both local and systemic diseases on the prevalence of this challenging disease.

What’s already known about this topic?

• Burning mouth syndrome is the sensation of oral burning unexplained by other disease.

• Published prevalence data on burning mouth syndrome are sparse and variable and were produced using a variety of burning mouth syndrome definitions and populations.

What does this study add?

• This is the first population-based prevalence study of burning mouth syndrome.

• The study shows that when defined by specific diagnostic criteria, burning mouth syndrome is less prevalent than previously described.

Abbreviations

BMS

burning mouth syndrome

REP

Rochester Epidemiology Project