Burning Mouth Syndrome - New Diagnostic Criteria and Treatment (BMS)

The first part of this study is to optimize diagnostic criteria for BMS, i.e. not a clinical trial, and will not be covered in this application. The second part will compare topical treatment with clonazepam, capsaicin and placebo in a n-of-1 study design regarding effects of pain, pain-related disability, somatosensory changes in the trigeminal nerve and patient experience in patients with primary BMS or other oral mucosal pain. The patients will be treated for two weeks with each drug, with a one-week wash-out period in between. After the last washed-out period, the patients will be able to chose the treatment that they prefer the most and continue with that treatment during 6 months.

The clinical trial in the present study will investigate treatment effects on pain, pain-related disability, jaw function and patients' experiences by topical treatment with clonazepam or capsaicin in comparison with placebo in patients with BMS or other oral mucosal pain. Twenty patients with primary BMS and 20 patients with other oral mucosal pain will be included. The study will comprise a n-of-1-design where each participant will be it's own control. The study will compare topical treatment with clonazepam, capsaicin and placebo regarding effects of pain, pain-related disability, somatosensory changes in the trigeminal nerve and patient experience. primary outcome will be pain intensity and patient experience. The patients will be treated for two weeks with each drug, with a one-week wash-out period in between. After the last washed-out period, the patients will be able to chose the treatment that they prefer the most and continue with that treatment during 6 months. After this 6 months, pain, pain-related disability, somatosensory changes in the trigeminal nerve and patient experience will be assessed again.

BMS, Chronic pain, Pain-related disability, Somatosensory changes, clonazepam, capsaicin, oral mucosa

N-of-1 design. Three two-week treatment arms with a one-week wash-out period in between. After that, the patient will chose their preferred treatment and continue with that treatment for 6 months (i.e. this part is not randomized or controlled).

One clinical examinator for all examinations (baseline examination, outcome assessments), randomization, allocation and drug management by another person,

Topical treatment of oral mucosa with a 3-min lozenge tablet with clonazepam (0.5 mg), three times a day.

Topical treatment of oral mucosa with capsaicin rinsing solution (XXXX IE) for three min three times a day.

Topical treatment of oral mucosa with rinsing solution without capsaicin for three min three times a day.

Overall oral mucosa pain intensity. Will be assessed using the subscale "Characteristic pain intensity" (three numerical rating scales 0 - 10 assessing current pain. intensity as well as worst and average pain intensity during the last two weeks) in the Graded Chronic Pain Scale

Overall oral mucosa pain intensity. Will be assessed using the subscale "Characteristic pain intensity" (three numerical rating scales 0 - 10 assessing current pain. intensity as well as worst and average pain intensity during the last two weeks) in the Graded Chronic Pain Scale

Overall oral mucosa pain intensity. Will be assessed using the subscale "Characteristic pain intensity" (three numerical rating scales 0 - 10 assessing current pain. intensity as well as worst and average pain intensity during the last two weeks) in the Graded Chronic Pain Scale

Point measurement, will be assessed the day after each treatment period is finished (22 days after start of each treatment)

Patient satisfaction with the treatment tested. Will be assessed using a numerical rating scale 0 - 10 where 0 = very dissatisfied and 10 = very satisfied.

Patient satisfaction with the treatment tested. Will be assessed using a numerical rating scale 0 - 10 where 0 = very dissatisfied and 10 = very satisfied.

Patient satisfaction with the treatment tested. Will be assessed using a numerical rating scale 0 - 10 where 0 = very dissatisfied and 10 = very satisfied.

Point measurement, will be assessed the day after each treatment period is finished (22 days after start of each treatment)

Pain-related disability from oral mucosal pains. Will be assessed using the subscale "Pain-related Disability" (three numerical rating scales 0 - 10 assessing impact on the oral pain on general, social and work-related activities during the last two weeks) in the Graded Chronic Pain Scale

Point measurement, will be assessed immediately before start of treatment as well as one, two and three weeks after treatment start.

Inclusion Criteria: Diagnosis of primary BMS according to International Classification of Orofacial Pain (ICOP) OR diagnosis of other oral mucosal pains according to ICOP Exclusion Criteria: Fibromyalgia IBS Reflux Recent (<3 months) intraoral surgical procedure Ongoing medication with Clonazepam or Capsaicin