March 2010

A New and Specific Definition of Burning Mouth Syndrome (BMS)

BMS has commonly been considered a complex clinical phenomena based upon several symptoms including oral burning, phantageusia (presence of a distorted taste in the mouth in the absence of any obvious oral stimulus), xerostomia (dry mouth) and/or loss of taste and/or smell acuity, occurring in older adults, most commonly in post menopausal women.

This definition has neither been useful to define BMS nor useful to develop treatment strategies.

Based upon our experience over the past 20 years with patients with BMS I now define BMS as consisting of one symptom and two findings:

The Symptom

• pyrosis or a burned sensation in one or several regions of the oral cavity

The Findings

• no anatomical or pathological change in the character of the oral mucous membranes

• no associated local or systemic symptom or pathology

There may be other symptoms which may accompany these three obligatory criteria. These other symptoms may include phantageusia, xerostomia and loss of taste and/or smell acuity but incidence of these symptoms are variable.

I consider BMS a type of sensory distortion or oral pain. While it occurs from a variety of clinical causes the most common cause is at present unknown or idiopathic.

The importance of my definition lies in distinguishing BMS from a myriad of other disorders which mimic it or may be confused with it. These include disorders of an infectious, nutritional, local or systemic neurological, dermatological, endocrinological, immunological or autoimmunological, local oral, local irritation, drug treatment, allergic, gastrointestinal malabsorptive, oncological, atypical pain perceptual, psychological or x-irradiation induced etiology in which the obligatory and limiting criteria I propose for this syndrome are not met.

Confusion as to the definition of this syndrome has been one reason for both the inability to characterize this syndrome clearly or to establish effective therapy.

With use of this definition I have related BMS, as previously reported in What’s New in May and October of 2005, to decreased levels of brain neurotransmitters, mainly gamma-aminobutyric acid (GABA), which normally inhibit unwanted sensory signals which can generate pyrosis but because of their decreased brain concentration they do not inhibit these sensory signals.

There is no oral cavity pathology responsible for this syndrome.

With this definition it is now possible to define specific treatment for this disorder based upon diminished levels of brain GABA.