Medical comorbidities in patients with lichen planopilaris, a retrospective case-control study

Lichen Planus: What is New in Diagnosis and Treatment?

Lichen planus (LP), an idiopathic, multifaceted chronic inflammatory disease with a heterogeneous clinical presentation, affects approximately 0.5-1% of the population. The various clinical manifestations of LP fall into three broad categories, namely cutaneous, appendageal, and mucosal, with further subclassification depending on the morphology and distribution patterns of individual lesions. There is mounting evidence that LP has systemic associations, including autoimmune conditions, glucose intolerance, dyslipidemia, and cardiovascular disorders. Cutaneous hypertrophic and mucosal forms of LP are at a heightened risk for malignant transformation. Familiarity with these potential associations in conjunction with long-term follow-up and regular screening could lead to a timely diagnosis and management of concomitant conditions. In addition, the frequent quality of life (QoL) impairment in LP underscores the need for a comprehensive approach including psychological evaluation and support. Several treatment strategies have been attempted, though most of them have not been adopted in clinical practice because of suboptimal benefit-to-risk ratios or lack of evidence. More recent studies toward pathogenesis-driven treatments have identified Janus kinase inhibitors such as tofacitinib, phosphodiesterase-4 inhibitors such as apremilast, and biologics targeting the interleukin-23/interleukin-17 pathway as novel therapeutic options, resulting in a dramatic change of the treatment landscape of LP. This contemporary review focuses on the diagnosis and management of LP, and places emphasis on more recently described targeted treatment options.

Endocrine and metabolic comorbidities in primary cicatricial alopecia: A nationwide population-based study

Primary cicatricial alopecia (PCA) is a rare, scarring, hair loss disorder. Due to its low incidence, little is known about endocrine and metabolic comorbidities in patients with PCA. Thus, we aimed to investigate the association between PCA and endocrine and metabolic disorders. This nationwide, population-based, cross-sectional study included patients diagnosed with PCA or non-cicatricial alopecia (NCA) and normal individuals without history of alopecia registered in the Korean National Health Insurance Service database between January 1, 2011, and December 31, 2020. We calculated the odds ratios of endocrine and metabolic comorbidities of patients with PCA compared to all patients or age- and sex-matched patients with NCA or normal individuals using multivariable logistic regression models. A total of 3 021 483 individuals (mean age [SD], 38.7 [15.0] years, 1 607 380 [53.2%] men), including 11 956 patients with PCA, 601 852 patients with NCA, and 2 407 675 normal participants, were identified. Patients with PCA had an increased risk for dyslipidemia (adjusted odds ratio [aOR] 1.14, 95% confidence interval [CI] 1.06-1.24), diabetes (aOR 1.38, 95% CI 1.24-1.53), and hypertension (aOR 1.10, 95% CI 1.02-1.19) compared to matched patients with NCA. Regarding PCA subtypes, lichen planopilaris/frontal fibrosing alopecia was positively associated with hypothyroidism (aOR 2.03, 95% CI 1.44-2.86) compared to NCA. Folliculitis decalvans and dissecting cellulitis were positively associated with dyslipidemia (aOR 1.16, 95% CI 1.05-1.28 and aOR 1.16, 95% CI 1.04-1.29, respectively), diabetes (aOR 1.38, 95% CI 1.20-1.58 and aOR 1.52, 95% CI 1.32-1.74, respectively), and hypertension (aOR 1.10, 95% CI 1.00-1.20 and aOR 1.14, 95% CI 1.02-1.27, respectively). Similar trends were observed when each PCA subgroup was compared with the normal control group. This study demonstrates that patients with PCA are more likely to have endocrine and metabolic comorbidities than patients without PCA. Further research on these comorbidities may improve the understanding of PCA.

Prevalence and incidence of comorbid diseases and mortality risk associated with lichen planopilaris: a Korean nationwide population-based study

BACKGROUND

Various comorbid diseases have been reported in patients with lichen planopilaris (LPP); however, data regarding the risks of incident diseases and mortality are lacking.

OBJECTIVES

To investigate the risks of incident diseases and mortality associated with LPP.

METHODS

This was a retrospective nationwide population-based study, using data from the National Health Insurance Service Database of Korea from 2002 to 2019. Patients aged ≥ 18 years with three or more documented medical visits for LPP were included. The adjusted hazard ratios (aHRs) for incident disease outcomes and mortality were compared with 1 : 20 age-, sex-, insurance type- and income-level-matched controls.

RESULTS

In total, 2026 patients with LPP and 40 520 controls were analysed. The risks of incident systemic lupus erythematosus [aHR 1.91, 95% confidence interval (CI) 1.21-3.03], psoriasis (aHR 3.42, 95% CI 2.83-4.14), rheumatoid arthritis (aHR 1.39, 95% CI 1.19-1.63), lichen planus (aHR, 10.07, 95% CI 7.17-14.15), atopic dermatitis (aHR 2.15, 95% CI 1.90-2.44), allergic rhinitis (aHR 1.29, 95% CI 1.13-1.49), thyroid diseases (hyperthyroidism: aHR 1.42, 95% CI 1.14-1.77, hypothyroidism aHR 1.19 95% CI 1.01-1.41, and thyroiditis: aHR, 1.35, 95% CI 1.08-1.69), nonmelanoma skin cancer (aHR 2.33, 95% CI 1.00-5.44) and vitamin D deficiency (aHR 1.23, 95% CI 1.03-1.47) were higher in patients with LPP. Patients with LPP had a higher mortality rate than controls (aHR 1.30, 95% CI 1.04-1.61), although the risk was not significant after adjusting for comorbidities (aHR 1.08, 95% CI 0.87-1.34).

CONCLUSIONS

Patients with LPP had a higher risk of various diseases following LPP diagnosis. Close follow-up is needed to optimize comprehensive patient care.

Comprehensive Insight into Lichen Planus Immunopathogenesis

Lichen planus is a chronic disease affecting the skin, appendages, and mucous membranes. A cutaneous lichen planus is a rare disease occurring in less than 1% of the general population, while oral illness is up to five times more prevalent; still, both forms equally impair the patient's quality of life. The etiology of lichen planus is not entirely understood. Yet, immune-mediated mechanisms have been recognized since environmental factors such as hepatitis virus infection, mechanical trauma, psychological stress, or microbiome changes can trigger the disease in genetically susceptible individuals. According to current understanding, lichen planus immunopathogenesis is caused by cell-mediated cytotoxicity, particularly cytotoxic T lymphocytes, whose activity is further influenced by Th1 and IL-23/Th-17 axis. However, other immunocytes and inflammatory pathways complement these mechanisms. This paper presents a comprehensive insight into the actual knowledge about lichen planus, with the causal genetic and environmental factors being discussed, the immunopathogenesis described, and the principal effectors of its inflammatory circuits identified.

Study of the Thyroid Profile of Patients with Alopecia

Thyroid hormones are required for the physiological growth and maintenance of hair follicles. We aim to study the thyroid profile of patients with alopecia. This is a narrative review. PubMed literature was searched from 2013 to 2022. We followed different types of alopecia: alopecia areata (AA), androgenic alopecia in males and females, telogen effluvium (TE), frontal fibrosing alopecia (FFA), lichen planopilaris, and alopecia neoplastica (AN). AA shares a common autoimmune background with autoimmune thyroid diseases, either sporadic or belonging to autoimmune polyglandular syndromes. Some data suggested that AA is more severe if thyroid anomalies are confirmed, including subclinical dysfunction or positive antithyroid antibodies with normal hormone values. However, routine thyroid screening for patients with AA, if the patients are asymptomatic from a thyroid point of view and they have negative personal and family history of autoimmunity, remains controversial. TE, apart from the autoimmune type, associates thyroid anomalies of a hormonal assay (between 5.7% and 17%). FFA, mostly a postmenopausal entity (however, not exclusive), associates a higher prevalence of thyroid conditions (up to 50%) than the general population. However, these might have an age-dependent pattern, thus the association may be incidental since there are a limited number of studies. Overall, alopecia remains a very challenging condition for patients and physicians; a multidisciplinary team is required to improve the outcome and quality of life. The common autoimmune background is suggestive of some types of alopecia and thyroid disorders, yet, the underlying mechanisms are still a matter of debate. AA, TE, FFA, LPP, and, potentially, female pattern hair loss have been found to be connected with thyroid entities, thus a state of awareness from a dual perspective, of trichology and endocrinology, is helpful.

Comorbidities in Patients with Vitiligo: A Systematic Review and Meta-Analysis

Vitiligo has been reported to be associated with a variety of diseases, but it has not been systematically reviewed. Therefore, we aimed to identify prevalent diseases in patients with vitiligo and quantify their associations compared with those in healthy controls. A comprehensive search of MEDLINE and EMBASE from the inception to June 2022 was conducted. Observational studies on prevalent diseases in patients with vitiligo compared with those in healthy controls were included, whereas studies limited to pediatrics or providing only laboratory results were excluded. A total of 78 studies were eligible for analyses. Patients with vitiligo showed higher risks of having comorbid autoimmune and connective tissue diseases, including alopecia areata (OR = 2.63, 95% confidence interval [CI] = 2.50‒2.78), discoid lupus erythematosus (OR = 2.54, 95% CI = 1.74‒3.72), Sjogren's syndrome (OR = 2.50, 95% CI = 1.98‒3.16), myasthenia gravis (OR = 2.30, 95% CI = 1.74‒3.02), systemic lupus erythematosus (OR = 1.96, 95% CI = 1.52‒2.52), and rheumatoid arthritis (OR = 1.82, 95% CI = 1.55‒2.15). Thyroid diseases, diabetes mellitus, metabolic syndrome, sensorineural hypoacusis, and ophthalmic abnormalities were also more prevalent in patients with vitiligo. In conclusion, vitiligo is associated with various systemic diseases. Physicians should evaluate and manage potential comorbid conditions in patients with vitiligo.

Frontiers in Lichen Planopilaris and Frontal Fibrosing Alopecia Research: Pathobiology Progress and Translational Horizons

Lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) are primary, lymphocytic cicatricial hair loss disorders. These model epithelial stem cell (SC) diseases are thought to result from a CD8⁺ T-cell‒dominated immune attack on the hair follicle (HF) SC niche (bulge) after the latter has lost its immune privilege (IP) for as yet unknown reasons. This induces both apoptosis and pathological epithelial‒mesenchymal transition in epithelial SCs, thus depletes the bulge, causes fibrosis, and ultimately abrogates the HFs' capacity to regenerate. In this paper, we synthesize recent progress in LPP and FFA pathobiology research, integrate our limited current understanding of the roles that genetic, hormonal, environmental, and other factors may play, and define major open questions. We propose that LPP and FFA share a common initial pathobiology, which then bifurcates into two distinct clinical phenotypes, with macrophages possibly playing a key role in phenotype determination. As particularly promising translational research avenues toward direly needed progress in the management of these disfiguring, deeply distressful cicatricial alopecia variants, we advocate to focus on the development of bulge IP and epithelial SC protectants such as, for example, topically effective, HF‒penetrating and immunoinhibitory preparations that contain tacrolimus, peroxisome proliferator-activated receptor-γ, and/or CB1 agonists.

Frontal Fibrosing Alopecia: A Review

Frontal fibrosing alopecia is a scarring alopecia, the prevalence of which is increasing worldwide since its first description in 1994. The reason for this emerging epidemic may be a higher exposure to an unknown trigger, although its aethiology and pathogenesis still remain enigmatic. Clinical, trichoscopic, sonographic, and histopathologic findings are allowing clinicians to understand more aspects about this type of cicatricial alopecia. Several treatments have been used in frontal fibrosing alopecia, although the 5-alpha reductase inhibitors seem to be the most promising. The aim of this report is to provide a compilation about the published data regarding frontal fibrosing alopecia in a narrative review.

Frontal fibrosing alopecia: a disease that remains enigmatic

Frontal fibrosing alopecia (FFA) is recognized to represent a generalized process of inflammatory scarring alopecia. Apart from the classic form affecting the frontal hairline, there are a range of disease manifestations involving loss of eyebrows and of eyelashes, loss of peripheral body hair, fibrosing alopecia in a pattern distribution, facial and extrafacial skin, mucous membrane, and nail involvement. Classic linear, diffuse “zigzag”, pseudo “fringe sign”, androgenetic alopecia-like, cockade-like, ophiasis-like and incomplete patterns are distinguished. The aetiology of FFA remains obscure, but a number of pathogenetic hypotheses and treatments to halt disease progression have been proposed.