Burning mouth syndrome: Clinical description, pathophysiological approach, and a new therapeutic option

Innovative histological and histochemical characterization of tongue biopsies from patients with burning mouth syndrome

OBJECTIVES

The present pilot study aims to perform an innovative histological and histochemical characterization of samples from patients with burning mouth syndrome (BMS) to correlate these findings with the clinical scenario.

METHODS

To carry out this objective, the study samples were stained with the hematoxylin-eosin stain and later, an histochemical study was carried out to determine the composition of the extracellular matrix (ECM) using the stains of Alcian Blue, Picrosirius, Reticulin from Gomori and Verhoeff.

RESULTS

The results of this study revealed histological patterns compatible with cellular hypertrophy in different layers of the epithelium as well as a greater keratinization in BMS cases. On the other hand, a lower amount of proteoglycans and a greater amount of collagen fibers were observed compared to the control. In addition, older patients had fewer reticular fibers and younger patients had fewer elastic fibers compared to the control.

CONCLUSIONS

In conclusion, the present study shows the existence of a correlation between the histological patterns, age and symptoms of patients with BMS. Therefore, it is necessary to develop synergistic studies in order to assess and implement new classification systems that could improve the therapeutic approach of patients with BMS.

Salivary metabolome indicates a shift in tyrosine metabolism in patients with burning mouth syndrome: a prospective case-control study

ABSTRACT

The pathophysiology of primary burning mouth syndrome (BMS) remains controversial. Targeted analyses or "omics" approach of saliva provide diagnostic or pathophysiological biomarkers. This pilot study's primary objective was to explore the pathophysiology of BMS through a comparative analysis of the salivary metabolome among 26 BMS female cases and 25 age- and sex-matched control subjects. Secondary objectives included comparative analyses of inflammatory cytokines, neuroinflammatory markers, and steroid hormones among cases and control subjects, and among BMS patients according to their clinical characteristics. Salivary metabolome, neuroinflammatory markers, cytokines, and steroids were, respectively, analysed by liquid chromatography coupled with mass spectrometry, ELISA and protease activity assay, and multiparametric Luminex method. Among the 166 detected metabolites, univariate analysis did not find any discriminant metabolite between groups. Supervised multivariate analysis divided patients into 2 groups with an accuracy of 60% but did not allow significant discrimination (permutation test, P = 0.35). Among the metabolites contributing to the model, 3 belonging to the tyrosine pathway ( l -dopa, l -tyrosine, and tyramine) were involved in the discrimination between cases and control subjects, and among BMS patients according to their levels of pain. Among the detectable molecules, levels of cytokines, steroid hormones, and neuroinflammatory markers did not differ between cases and control subjects and were not associated with characteristics of BMS patients. These results do not support the involvement of steroid hormones, inflammatory cytokines, or inflammatory neurogenic mediators in the pathophysiology of pain in BMS, whereas the observed shift in tyrosine metabolism may indicate an adaptative response to chronic pain or an impaired dopaminergic transmission.

Síndrome de boca ardiente, abordaje otorrinolaringológico. Revisión bibliográfica sistemática

Introducción y objetivo: El síndrome de boca ardiente (SBA) es una afección crónica, que cursa con quemazón o dolor de la mucosa bucal, afectando predominantemente a mujeres de edad media. Puede aparecer como cuadro primario o bien de forma secundaria. La fisiopatología de esta entidad es bastante desconocida. Existe un amplio abanico terapéutico, pero por lo general precisa de un abordaje multidisciplinar. Nuestra intención es realizar una puesta al día de la enfermedad para poder hacerla frente en la consulta de otorrinolaringología. Método: Revisión bibliográfica de la literatura. Fecha de publicación limitada de 2012 a 2022. Resultados: El SBA presenta una etiopatogenia de carácter multifactorial. Para su diagnóstico es necesario realizar una exhaustiva anamnesis y exploración. Se diferencian 3 tipos distintos de SBA, siendo el tipo II el más frecuente y el más refractario a la terapia. El adecuado tratamiento se fundamenta en un correcto diagnóstico y debe ser multidisciplinar. Discusión: Es importante resaltar que es una entidad benigna. Los tratamientos son variados y no hay ninguno que destaque sobre el resto, lo que dificulta el manejo de estos pacientes. Aunque la bibliografía sobre este síndrome es abundante, no se han producido en los últimos años, importantes innovaciones en cuanto a la etiología y tratamiento. Conclusiones: La anamnesis y los estudios de laboratorio son fundamentales para descartar casusas secundarias de la enfermedad. La terapia es diversa y debe incluir derivación a salud mental como parte del manejo multidisciplinar.  

Efficacy of photobiomodulation in reducing pain and improving the quality of life in patients with idiopathic burning mouth syndrome. A systematic review and meta-analysis

Burning mouth syndrome is a chronic condition, which is characterised by a burning sensation or pain in the mucosa of the oral cavity. Treatment options include antidepressants, antipsychotics, anticonvulsants, analgesics, hormone replacement therapies and more recently photobiomodulation. This study aims to perform a systematic review with meta-analysis in order to determine the effect of photobiomodulation on pain relief and the oral health-related quality of life associated with this condition. A bibliographical search of the Pubmed, Embase, Web of Science and Scopus databases was conducted. Only randomised clinical trials were included. Pain and quality of life were calculated as mean difference and pooled at different treatment points (baseline = T0 and final time point = Tf) and laser modality. From a total of 103 records, 7 articles were retrieved for inclusion. PBM group had a greater decrease in pain than control group at Tf with a mean difference =  − 2.536 (IC 95% − 3.662 to − 1.410; I² = 85.33%, p < 0.001). An improvement in oral health-related quality of life was observed in both groups, although this was more significant in the photobiomodulation group mean difference =  − 5.148 (IC 95% − 8.576 to − 1.719; I² = 84.91%, p = 0.003). For the red laser, a greater improvement than infrared was observed, in pain, mean difference =  − 2.498 (IC 95% − 3.942 to − 1.053; I² = 79.93%, p < 0.001), and in quality of life, mean difference =  − 8.144 (IC 95% − 12.082 to − 4.206; I² = 64.22%, p = 0.027). Photobiomodulation, in particular, red laser protocols, resulted in improvement in pain and in quality of life of burning mouth syndrome patients.

Dopamine agonist responsive burning mouth syndrome: Report of eight cases

BACKGROUND

Burning mouth syndrome (BMS) is characterized by burning sensation of the oral mucosa. There is a lack of effective treatment. In recent years, a special subtype of BMS has been reported, in which oral burning sensation is alleviated after chewing, speaking, or dopaminergic drug delivery. Currently, there are few reports about the subtype of BMS in China. This study was a retrospective analysis of the clinical data of BMS patients sensitive to dopamine agonist at our hospital, aiming to improve the recognition on this disease.

CASE SUMMARY

Eight patients diagnosed with dopamine agonist responsive BMS at the Liaocheng People's Hospital from January 1, 2017 to June 30, 2020 were recruited. The clinical manifestations, treatment, and prognosis were retrospectively analyzed. There were three male and five females in the eight patients. The median age was 56 years (range, 46-65 years). All the eight patients showed burning pain in the mouth. The symptoms were mild in the morning and severe in the evening, and alleviated after chewing, talking, and other oral activities. Four patients were accompanied by restless legs syndrome (RLS). Family history of RLS was positive in two patients. All patients were treated with pramipexol, and symptoms were basically relieved after 2-8 wk.

CONCLUSION

Dopamine agonist responsive BMS is a special subtype of BMS, which is alleviated after oral activities. Dopamine receptor agonist is an effective treatment.

How and when to refer patients diagnosed with secondary headache and other craniofacial pain in the Emergency Department and Primary Care: Recommendations of the Spanish Society of Neurology's Headache Study Group

INTRODUCTION

When secondary headache is suspected and the patient is referred to the emergency department or to the outpatient neurology clinic, it is important to know which are the appropriate complementary examinations to perform and the suitable referral pathway for patients to follow. In order to establish recommendations on this matter, the Spanish Society of Neurology's Headache Study Group (GECSEN) has decided to issue a series of agreed recommendations constituting a referral protocol for patients with headache and/or craniofacial neuralgias.

DEVELOPMENT

Young neurologists with an interest and experience in headache were invited to draft a series of practical guidelines in collaboration with GECSEN's Executive Committee. For practical reasons, the document was divided into 2 articles: the first focuses on primary headaches and craniofacial neuralgias and this second article on secondary headaches and other craniofacial pain. In order for the recommendations to be helpful for daily practice, they follow a practical approach, with tables summarising referral criteria, examinations to be performed, and referral to other specialists.

CONCLUSIONS

We hope to offer a guide and tools to improve decision-making regarding patients with headache, identifying complementary tests to prioritise and referral pathways to be followed, in order to avoid duplicated consultations and delayed diagnosis and treatment.

Profiling intraoral neuropathic disturbances following lingual nerve injury and in burning mouth syndrome

Background

The aim of the study was to analyse intraoral neurophysiological changes in patients with unilateral lingual nerve lesions as well as patients with Burning Mouth Syndrome (BMS) by applying a standardized Quantitative Sensory Testing (QST) protocol.

Methods

The study included patients suffering from a peripheral lesion of the lingual nerve (n = 4), from BMS (n = 5) and healthy controls (n = 8). Neurophysiological tests were performed in the innervation areas of the tongue bilaterally. For BMS patients the dorsal foot area was used as reference.

Results

For patients with peripheral lesion of the lingual nerve the affected side of the tongue showed increased thresholds for thermal (p < 0.05–0.001) and mechanical (p < 0.01–0.001) QST parameters, indicating a hypoesthesia and thermal hypofunction. In BMS patients, a pinprick hypoalgesia (p < 0.001), a cold hyperalgesia (p < 0.01) and cold/warmth hypoesthesia (p < 0.01) could be detected.

Conclusions

The results of this study verified the lingual nerve lesion in our patients as a peripheral dysfunction. The profile showed a loss of sensory function for small and large fibre mediated stimuli. A more differentiated classification of the lingual nerve injury was possible with QST, regarding profile, type and severity of the neurologic lesion. BMS could be seen as neuropathy with variable central and peripheral contributions among individuals resulting in chronic pain.