Oral lichen planus and thyroid gland diseases: possible associations

The Correlation between Oral Lichen Planus and Thyroid Pathologies: A Retrospective Study in a Sample of Italian Population

OBJECTIVES

 The association between oral lichen planus and thyroid disorders, especially hypothyroidism and Hashimoto's thyroiditis, has been discussed in current literature with conflicting outcomes.

MATERIALS AND METHODS

 The study retrospectively evaluated the thyroid status in patients diagnosed with oral lichen planus and oral lichenoid lesions. A case-control approach was used to prove that thyroid disorders were statistically significant risk factors for oral lichen planus and oral lichenoid lesions.

STATISTICAL ANALYSIS

 To evaluate these associations, odds ratios (ORs) were used. ORs precision and statistical significance were estimated using a 95% confidence interval (CI) and p-value, respectively.

RESULTS

 A total of 307 patients were involved in the study: 158 females and 149 males. OR, 95% CIs, and p-values were analyzed. Patients with thyroid diseases showed an increased risk of developing oral lichen planus (OR: 4.29, 95% CI: 1.85-9.96, p-value: 0.0007) and oral lichenoid lesions (OR: 2.76, 95% CI: 1.24-6.13, p-value: 0.0129). This association was maintained in patients with oral lichen planus, while also considering hypothyroidism (OR: 3.74, 95% CI: 1.46-9.58, p-value: 0.0059) and Hashimoto's thyroiditis (OR: 4.57, 95% CI: 1.58-13.23, p-value: 0.005) alone. The correlation of hypertension, diabetes, dyslipidemia, and smoking status with oral lichen planus and oral lichenoid lesions was also evaluated but no statistical significance was found.

CONCLUSION

 Even if further investigations are needed, the association between oral lichen planus and oral lichenoid lesions with thyroid pathologies should be taken into consideration by endocrinologists due to the potential malignancy of these disorders.

Oral Lichen Planus: An Updated Review of Etiopathogenesis, Clinical Presentation, and Management

Lichen planus (LP) is a chronic idiopathic immune-mediated inflammatory condition. LP is a heterogeneous disease with varied clinical presentations having different natural history, prognosis, sequelae, and outcomes. It can affect skin, hair, nails, and mucosae. Mucosal LP (including oral LP) tends to be persistent and resistant to treatment, compared to cutaneous LP. Oral LP (OLP) is broadly divided into two main categories: hyperkeratotic (usually asymptomatic) and erosive (commonly symptomatic). It can present with symptoms including odynophagia, dysphagia, dysgeusia, and sensitivity to hot spicy foods. Apart from the superficial epidermal changes, which vary with the type of clinical presentation, histopathologically oral LP shows a unifying similar and consistent feature of a lichenoid interface dermatitis. Recently, researchers have highlighted the critical role played by IL-17 in the pathogenesis of OLP. World Health Organization has categorized oral LP as one of the oral potentially malignant disorders (OPMD), albeit with a low risk of malignant transformation. Also, in the last couple of years there have been various reports on the usage of newer drugs like anti-IL17, anti-IL12/23, anti-IL 23, PDE4 inhibitors, and JAK inhibitors in the management of refractory OLP. The principal aim of treatment still remains to resolve the symptoms, prolong the symptoms free period, and reduce the risk of potential malignant transformation. We have described many new revelations made in recent times regarding the etiopathogenesis, associated conditions as well as management of OLP. Thus, the objective of this review is to present a comprehensive up-to-date knowledge including the recent advances made regarding OLP.

Crossroads between Skin and Endocrine Glands: The Interplay of Lichen Planus with Thyroid Anomalies

In this narrative review, we aimed to overview the interplay between lichen planus (LP) and thyroid conditions (TCs) from a dual perspective (dermatologic and endocrine), since a current gap in understanding LP-TC connections is found so far and the topic is still a matter of debate. We searched PubMed from Inception to October 2023 by using the key terms "lichen planus" and "thyroid", (alternatively, "endocrine" or "hormone"). We included original clinical studies in humans according to three sections: LP and TC in terms of dysfunction, autoimmunity, and neoplasia. Six studies confirmed an association between the thyroid dysfunction (exclusively hypothyroidism) and LP/OL (oral LP); of note, only one study addressed cutaneous LP. The sample size of LP/OLP groups varied from 12-14 to 1500 individuals. Hypothyroidism prevalence in OLP was of 30-50%. A higher rate of levothyroxine replacement was identified among OLP patients, at 10% versus 2.5% in controls. The highest OR (odd ratio) of treated hypothyroidism amid OLP was of 2.99 (p < 0.005). Hypothyroidism was confirmed to be associated with a milder OLP phenotype in two studies. A single cohort revealed a similar prevalence of hypothyroidism in LP versus non-LP. Non-confirmatory studies (only on OLP, not cutaneous LP) included five cohorts: a similar prevalence of hypothyroidism among OLP versus controls, and a single cohort showed that the subjects with OLP actually had a lower prevalence of hypothyroidism versus controls (1% versus 4%). Positive autoimmunity in LP/OLP was confirmed in eight studies; the size of the cohorts varied, for instance, with 619 persons with LP and with 76, 92, 105, 108, 192, 247, and 585 patients (a total of 1405) with OLP, respectively; notably, the largest control group was of 10,441 individuals. Four clusters of approaches with respect to the autoimmunity in LP/OLP were found: an analysis of HT/ATD (Hashimoto's thyroiditis/autoimmune thyroid diseases) prevalence; considerations over the specific antibody levels; sex-related features since females are more prone to autoimmunity; and associations (if any) with the clinical aspects of LP/OLP. HT prevalence in OLP versus controls was statistically significantly higher, as follows: 19% versus 5%; 12% versus 6%; and 20% versus 9.8%. A single study addressing LP found a 12% rate of ATDs. One study did not confirm a correlation between OLP-associated clinical elements (and OLP severity) and antibody values against the thyroid, and another showed that positive TPOAb (anti-thyroperoxidase antibodies) was more often found in erosive than non-erosive OLP (68% versus 33%). Just the reverse, one cohort found that OLP subjects had a statistically significantly lower rate of positive TPOAb versus controls (9% versus 15%). Five case-control studies addressed the issue of levothyroxine replacement for prior hypothyroidism in patients that were diagnosed with OLP (no study on LP was identified); three of them confirmed a higher rate of this treatment in OLP (at 8.9%, 9.7%, and 10.6%) versus controls. In conclusion, with regard to LP/OLP-TC, we note several main aspects as practical points for multidisciplinary practitioners: OLP rather than LP requires thyroid awareness; when it comes to the type of thyroid dysfunction, mostly, hypothyroidism should be expected; female patients are more prone to be associated with ATDs; a potential higher ratio of OLP subjects taking levothyroxine was found, thus a good collaboration with an endocrinology team is mandatory; and so far, OLP individuals have not been confirmed to be associated with a higher risk of thyroid nodules/cancer.

Risk of Prediabetes and Diabetes in Oral Lichen Planus: A Case-Control Study according to Current Diagnostic Criteria

OBJECTIVE

To estimate the prevalence of prediabetes and diabetes in patients with oral lichen planus (OLP).

METHODS

Prospective cohort, including consecutive patients diagnosed clinically and histologically with OLP from 2018 to 2022. Patients and controls were matched by age and gender. Fasting plasma glucose value collection from all patients. Multivariate regression analysis evaluated the relationship between prediabetes and diabetes variables according to current diagnostic criteria.

RESULTS

The sample comprised 275 patients (207 women; 75.3%), mean age 59.60 ± 12.18 years for both groups. Prediabetes was diagnosed according to the American Diabetes Association (ADA, 100-125 mg/dL), in 21.45% of OLP patients (59/275) and 14.55% (40/275) of control patients (p = 0.035). Patients with the atrophic-erosive form exhibited stronger association with taking oral antidiabetics (p = 0.011). Multivariate analysis showed that being over >60 years and having a cutaneous location was associated with ≥3 sites (OR 1.81 and OR 2.43). ADA prediabetes and oral antidiabetics drugs increased the probability of OLP (OR 1.60 (1.04-2.51), p = 0.03 and OR 2.20 (1.18-4.69), p = 0.017) after adjustment for sex and age.

CONCLUSIONS

Because glycemia 100-125 mg/dL was associated with OLP, testing serum fasting plasma glucose seems reasonable in order to prevent development of diabetes and deal with possible complications until new studies are complete.

Oral lichenoid lesion simultaneously associated with Castleman's disease and papillary thyroid carcinoma: a rare case report

BACKGROUND

Oral lichenoid lesion (OLL) is a term used to describe oral lesions that have clinical and/or histopathological features similar to oral lichen planus (OLP), but it is thought to be caused by specific triggers or systemic conditions and presents higher malignant transformation rate than OLP. To date, OLL simultaneously complicated with Castleman's disease (CD) and papillary thyroid carcinoma (PTC) has not been reported. Reporting from such disorders is crucial to avoid misdiagnosis and help in timely intervention.

CASE PRESENTATION

We report a rare case of a 39-year-old female with extensive ulcerated lesions on the oral mucosa, diagnosed as OLL by histopathology. Routine oral treatment was scheduled to control the OLL, while the oral lesions remained unhealed. Computed tomography examination was performed after the oral treatment and revealed thyroid and mediastinal masses, which were then surgically removed and pathologically diagnosed as PTC and CD, respectively. Two months after complete excision of the neoplasms, the oral lesions showed obvious alleviation. With subsequent treatment for oral lesions, the patient's OLL healed.

CONCLUSIONS

This is the first reported OLL case simultaneously associated with CD and PTC. This case reminds us to focus on the underlying etiologies of OLL and the multidisciplinary collaboration for oral lesions associated with systemic diseases.

Diabetes mellitus and oral lichen planus: A systematic review and meta-analysis

OBJECTIVE

To undertake a meta-analysis of the association of Oral Lichen Planus (OLP) with diabetes, two diseases with an important impact on public health and the economy, but the evidence of which about their association is inconsistent.

METHODS

Relevant studies were localized by searching MEDLINE, EMBASE, Conference Proceedings, and other databases from inception to October 2020, without restrictions. The reference lists of included studies and of related reviews were also inspected. Global pooled odds ratios were calculated, and predefined subgroup analyses were performed. The heterogeneity between studies and publication bias was assessed and sensitivity analysis was carried out.

RESULTS

Thirty-two studies were included in the meta-analysis. Pooled ORs showed a moderate association between diabetes and OLP [OR: 1.87 (95%CI: 1.57, 2.34)]. The association is limited to studies carried out on adults only [OR: 2.12 (95%CI: 1.75, 2.57)] and is observed in all study designs. Globally, the heterogeneity was low to moderate. Studies carried out in European populations show a stronger association of diabetes and OLP than Asiatic studies [OR: 2.49 (95%CI: 1.87, 3.32) and 1.60 (95%CI: 1.25, 2.03), respectively].

CONCLUSIONS

Diabetes and OLP are moderately associated. Systematic diagnosis of diabetes in OLP patients could prove useful.

Possible Mechanisms Involved in the Cooccurrence of Oral Lichen Planus and Hashimoto's Thyroiditis

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disorder mediated by T cells, with a multifactorial etiology. Hashimoto's thyroiditis (HT) is a common autoimmune disease characterized by hypothyroidism. Although many clinical studies conducted over the past several decades have reported the cooccurrence of OLP and HT, the underlying mechanism remains unclear. This review summarizes potential mechanisms that might be involved in the cooccurrence of OLP and HT. We find that OLP and HT share a common or overlapping pathogenesis in terms of immune, heredity, environmental, and hormonal factors, which might cause cooccurrence. Furthermore, considering the latency of HT, a routine screen for thyroid diseases, particularly HT, is suggested for confirmed OLP patients.