Neurogenic Mechanisms in Burning Mouth Syndrome

Study Overview
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Brief Summary
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Burning mouth syndrome (BMS) is characterized by a bilateral burning sensation in the anterior tongue, hard palate and lips in the absence of any clinical or laboratory findings. The term syndrome implicates the simultaneous presence of oral dryness (xerostomia) and altered taste (dysgeusia) in addition to the burning sensation in the oral mucosa. BMS is most often seen in women and is more frequent during menopause. The etiology and pathogenesis are still unclear but recent studies suggest that BMS is a neuropathic pain condition. The objectives of the study are: To clarify potential neurogenic mechanisms behind BMS using immunohistochemistry (IH) to characterize the localization and distribution of peripheral nerve fibres, neuropeptides like substance P, calcitonin gene-related peptide, nerve growth factor, nerve growth factor receptor, PGP 9.5 neuronal marker and TRPV1 as well as inflammatory/structural changes. To perform a randomized double blind cross-over intervention study to examine the efficacy and safety of topical application of capsaicin oral gel (on the tongue) to relieve the burning sensation in patients with BMS.

Detailed Description
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Data which support the hypothesis that BMS is a neuropathic pain condition include amongst others a recent clinically controlled study that has shown up-regulation of TRPV1-positive nerve fibres in tongue mucosa in patients with BMS. The vanilloid receptor-1 (TRPV1) is a voltage-dependent cation channel expressed by the unmyelinated C-nociceptive nerve fibres and the receptor may be activated by capsaicin (from chili peppers), heat and H+. Capsaicin binds to the TRPV1 receptor causing depolarization of the C-nociceptors. Prolonged activation of these neurons by capsaicin depletes pre-synaptic substance P and makes them unable to report pain.

Official Title
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Neurogenic Mechanisms in Burning Mouth Syndrome With Focus on Localization and Desensibilization of Vanilloid Receptor TRPV1

Conditions
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Burning Mouth Syndrome

Intervention / Treatment
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* Other: Capsaicin oral gel 0.025%
* Other: Capsaicin oral gel 0.01%


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: non-smoking female patients with burning mouth syndrome (n=26) healthy aged-matched control group (n=10) Exclusion Criteria: pregnancy and lactation (inclusion requires negative pregnancy test) women who do not use safe anticonception patients with know allergy/hypersensitivity to capsicum and other capsaicinoid-containing products Active infection which requires antibiotic treatment use of mouthrinse. The use of these is stopped 14 days before inclusion patients who are able to give informed consent due to physical or mental disabilities

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Capsaicin oral gel 0.01%<br> | Other: Capsaicin oral gel 0.01%<br>* Application 3 times daily for 14 days on the tongue, followed by 14 days wash-out<br>* Other names: Capsicum, extract from chilipepper;|
| Active Comparator: Capsaicin oral gel 0.025%<br> | Other: Capsaicin oral gel 0.025%<br>* Application 3 times daily for 14 days on the tongue, followed by 14 days wash-out<br>* Other names: Capsicum, extract from chilipepper;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Primary outcome: To evaluate the efficacy and safety of topical application of capsaicin oral gel (using to different concentrations) to relieve the burning sensation in patients with BMS and alleviate BMS related symptoms. |  | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To characterize the localization and distribution of peripheral nerve fibres, neuropeptides like substance P, calcitonin gene-related peptide, NGF, NGF-R, PGP 9.5 neuronal marker and TRPV1 as well as inflammatory/structural changes. |  | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Burning mouth syndrome, neuropathy, inflammation, tongue mucosa, tongue innervation, dysgeusia