Beyond skin white spots: Vitiligo and associated comorbidities

Vitiligo is a common depigmentation disorder of an unknown origin characterized by the selective loss of melanocytes, resulting in typical white macules and patches. However, vitiligo is now recognized as more than just a skin disease, what a dermatologist observes as a white spot of skin is just the "tip of the iceberg" of the condition. We attempt to clarify the classification of comorbidities associated with vitiligo from various reviews and reports, and describe their possible pathogenesis. In conclusion, the literature provides evidence of an association between vitiligo and ocular and auditory abnormalities, autoimmune disorders, other dermatological diseases, metabolic syndrome and related disorders, and psychological diseases. These associations highlight the importance of a multidisciplinary approach in managing vitiligo patients.

Immunometabolism in the pathogenesis of vitiligo

Vitiligo is a common depigmenting skin disorder characterized by the selective loss of melanocytes. Autoimmunity, genetic, environmental, and biochemical etiology have been proposed in vitiligo pathogenesis. However, the exact molecular mechanisms of vitiligo development and progression are unclear, particularly for immunometabolism. Sporadic studies have suggested mitochondrial dysfunction, enhanced oxidative stress, and specific defects in other metabolic pathways can promote dysregulation of innate and adaptive immune responses in vitiligo. These abnormalities appear to be driven by genetic and epigenetic factors modulated by stochastic events. In addition, glucose and lipid abnormalities in metabolism have been associated with vitiligo. Specific skin cell populations are also involved in the critical role of dysregulation of metabolic pathways, including melanocytes, keratinocytes, and tissue-resident memory T cells in vitiligo pathogenesis. Novel therapeutic treatments are also raised based on the abnormalities of immunometabolism. This review summarizes the current knowledge on immunometabolism reprogramming in the pathogenesis of vitiligo and novel treatment options.

Vitiligo and Metabolic Syndrome: Systematic Review and Meta-Analysis

BACKGROUND

Metabolic syndrome (MetS) has been associated with various skin conditions including vitiligo. However, the association between these 2 conditions has yet to be determined by quantitative meta-analysis.

OBJECTIVE

The aim of this paper was to determine the association between vitiligo and metabolic syndrome via systematic review and meta-analysis.

METHODS

A systematic literature search of Pubmed, Embase, Cochrane, and Web of Science was performed for all published literature prior to August 16, 2020. Case control and prospective cross-sectional studies analyzing the association between vitiligo and MetS were included in this review. The primary outcome measures include the type of vitiligo, diagnostic criteria for MetS, components of MetS (waist circumference, blood pressure, triglycerides, fasting glycemic index, and high-density lipoprotein cholesterol), low-density lipoprotein cholesterol levels, and BMI. A meta-analysis was performed to evaluate the prevalence and association of MetS in patients with vitiligo.

RESULTS

A total of 6 studies (n=734 participants) meeting eligibility criteria were included for systematic review and meta-analysis. The pooled prevalence of MetS in patients with vitiligo was (0.296, 95% CI 0.206, 0.386; P<.001). Patients with vitiligo were no more likely to develop MetS compared to control patients (odds ratio 1.66, 95% CI 0.83, 3.33; P=.01). A leave-one-out sensitivity analysis showed a significant association between MetS and vitiligo (P<.001). Significant elevations in fasting glycemic index (mean difference 5.35, 95% CI 2.77, 7.93; P<.001) and diastolic blood pressure (mean difference 1.97, 95% CI 0.02, 3.92; P=.05) were observed in patients with vitiligo compared to control patients.

CONCLUSIONS

The association between vitiligo and metabolic syndrome carries important clinical implications. Dermatologists and other multidisciplinary team members should remain vigilant when treating this patient population in order to prevent serious cardiovascular complications that may arise as a result of metabolic disease.

Increased risk of subclinical atherosclerosis and metabolic syndrome in patients with vitiligo: a real association or a coincidence?

Inflammatory and autoimmune skin diseases such as vitiligo may be associated with systemic disorders, including endocrine and cardiovascular diseases, due to some similarities in the pathogenesis. It was aimed to evaluate metabolic syndrome and subclinical atherosclerosis in patients with vitiligo. Seventy patients with nonsegmental vitiligo and 70 age-matched and gender-matched healthy controls participated in the study. These participants were investigated for metabolic syndrome criteria. The mean intima-media thickness of the common carotid artery (MIMT-CCA) of the subjects was measured for assessment of subclinical atherosclerosis. Metabolic syndrome and subclinical atherosclerosis were significantly more frequent in vitiligo patients compared with the controls (P = .006 and P = .002, respectively). In addition, metabolic syndrome and subclinical atherosclerosis had positive, significant correlations with the severity and duration of vitiligo (P = .031 and r = .482; P < .01, respectively). Our study suggested that patients with vitiligo, especially those with more chronic and severe disease or concomitant metabolic syndrome, are at a higher risk of developing cardiovascular diseases. Therefore, early diagnosis and treatment of metabolic syndrome in patients with vitiligo to prevent cardiovascular complications were recommended.

The association between melasma and iron profile: a case-control study

Background — Melasma is a chronic acquired localized hypermelanosis, causing aesthetic problem for women and impairing their quality of life. Evidence has suggested that hyperpigmentation can occur as a result of iron deficiency anemia and vitamin B12 deficiency. Aim — We aimed to evaluate the serum parameters of iron profile in melasma patients. Material and Methods — This case-control study investigated 51 adult non pregnant women with melasma, compared with 51 controls, from patients referred to the Hospital, Tehran, Iran, 2017–2018. Melasma was diagnosed clinically according to the melasma area and severity index (MASI) score was calculated and recorded by the physician. The groups were compared in terms of vitamin B12, folate, serum iron, hemoglobin (Hb), mean corpuscular volume (MCV), total iron binding capacity (TIBC), and ferritin. Results — The mean and standard deviation of the women’s age was 36.89±8.88 years, significantly higher in the group of patients with melasma. Comparing the serum parameters between the groups indicated no statistically significant difference in terms of mean levels of ferritin, Hb, MCV, iron, vitamin B12, TIBC, and folate. The women in melasma group had a higher frequency in below normal range of ferritin and serum iron compared to the control group. None of the serum parameters were correlated with MASI. Conclusion — The higher frequency of below normal range of ferritin and serum iron levels in women with melasma compared to the control group showed a possible association between these serum parameters and melasma.

Higher incidence of metabolic syndrome components in vitiligo patients: a prospective cross-sectional study

BACKGROUND/OBJECTIVES

To investigate the association between vitiligo and metabolic syndrome.

METHODS

A prospective cross-sectional study was conducted between 2014 and 2016. Study (n=155) and control groups (n=155) were evaluated for metabolic syndrome according to National Cholesterol Education Program Adult Treatment Panel III and the International Diabetes Federation criteria. Study group was divided into three groups according to their vitiligo area severity index and vitiligo disease activity score values (Group 1: 6.89 for VASI score, Group A: -1-0, Group B: 1-2 and Group C: 3-4 for vitiligo disease activity score respectively). MetS rates according to both criteria were compared between the vitiligo disease activity score and vitiligo area severity index groups.

RESULTS

Metabolic syndrome rates were 37.4% and 40% in the study group and 19.4% and 26.5% in the control group according to National CholesterolEducation Program Adult Treatment Panel III and International Diabetes Federation criteria, respectively (p<001 and p=0.011). Metabolic syndrome was more frequent in vitiligo area severity index Groups 2 and 3 compared to vitiligo area severity index Group 1, and in vitiligo disease activity score Group C compared to vitiligo disease activity score Groups A and B.

STUDY LIMITATIONS

Single center experience, absence of more specific oxidative-stress markers and lack of long-term follow-up of the patients.

CONCLUSIONS

Frequency of metabolic syndrome was higher in patients with non-segmental vitiligo and the rate was higher in active/severe form of the disease.

Association of MTHFR C677T polymorphism with elevated homocysteine level and disease development in vitiligo

Increasing evidence on the association of MTHFR gene polymorphism and serum homocysteine levels with autoimmune diseases such as vitiligo has made the MTHFR gene a very interesting candidate to be evaluated in different ethnicities and populations. We aimed to evaluate the levels of serum homocysteine and vitamin B12 and their associations with MTHFR C677T polymorphism in the Iranian population. This case-control study included 104 patients with vitiligo and 100 age- and sex-matched healthy control subjects. Serum vitamin B12 and homocysteine levels were measured by a chemiluminescence assay. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used for genotyping the polymorphism. The mean serum homocysteine levels were significantly higher in cases than controls and associated with disease activity (p < .001). Furthermore, the homozygous MTHFR C677T variant genotype was associated with vitiligo development (adjusted OR: 3.52, 95% CI: 1.09-11.32, p = .02) and elevated homocysteine level (p < .001). There was no association between serum vitamin B12 levels and the MTHFR C677T genotype. The homozygous variant MTHFR C677T may be considered as a risk factor for both elevated homocysteine levels and the development of vitiligo in the Iranian population. Although these results are not conclusive, they could elucidate the contribution of genetic and immune-mediated inflammatory factors to the pathogenesis of vitiligo.

Serum homocysteine, folate, and vitamin B12 levels in patients with vitiligo and their potential roles as disease activity biomarkers: A systematic review and meta-analysis

BACKGROUND

Hyperhomocysteinemia and folate and vitamin B₁₂ deficiencies have been reported in patients with vitiligo. Investigating the role of these conditions might shed light on the pathogenesis of vitiligo.

OBJECTIVE

To perform a systematic review and meta-analysis of studies assessing serum homocysteine, folate, and vitamin B₁₂ levels in vitiligo patients.

METHODS

Online databases were searched on May 15, 2018, to identify studies comparing serum homocysteine, folate, and vitamin B₁₂ levels between patients with vitiligo and controls. A random effects model was used.

RESULTS

Twenty-two studies involving a total of 1448 patients with vitiligo were included. Patients with vitiligo had significantly higher serum homocysteine levels (standardized mean difference [SMD] 0.550, 95% confidence interval [CI] 0.262-0.838; I² 87.3%) and lower vitamin B₁₂ levels (SMD -0.430, 95% CI -0.738 to -0.121; I² 85.3%) than controls. Serum folate levels were not significantly different between the 2 groups (SMD -0.240, 95% CI -0.592 to 0.111; I² 85.5%). A subgroup analysis revealed that these findings correlated with disease activity.

LIMITATIONS

The included studies were heterogeneous. Serum homocysteine levels could be influenced by various factors.

CONCLUSION

Patients with vitiligo have higher serum homocysteine levels and lower vitamin B₁₂ levels than individuals without vitiligo.

Metabolic syndrome in vitiligo patients among a semi-urban Maharashtrian population: A case control study

AIM

To assess the prevalence of metabolic syndrome and its correlation with the severity and duration of vitiligo.

METHODS

One hundred vitiligo patients and 100 age-and-sex matched controls were included, whose waist circumference and blood pressure were measured; fasting serum cholesterol, triglycerides and glucose levels quantified; disease severity assessed and metabolic syndrome defined by National Cholesterol Education Program (NCEP) criteria.

RESULTS

Metabolic syndrome (24%:12%), hypertriglyceridemia (41%:24%), impaired glucose tolerance (25%:16%) [P<0.05] and low HDL (P=0.044) were significantly more prevalent in cases as compared to controls as were the mean values of triglycerides and fasting blood sugar. Increased mean age of vitiligo patients correlated with the presence of metabolic syndrome.

CONCLUSION

Metabolic syndrome had significant presence in but remained unaffected by the severity of vitiligo in our study patients.

Neutrophil to lymphocyte ratio in patients with vitiligo

Introduction

There are a few studies showing an increased risk of insulin resistance, metabolic syndrome, and oxidative stress in patients with vitiligo.

Aim

To investigate whether systemic inflammation is increased in vitiligo patients in a case-control study design.

Material and methods

Nonsegmental vitiligo patients who had been followed at the outpatient dermatology clinic of a university-affiliated teaching hospital, and healthy controls were enrolled in the study. Patients who were receiving systemic treatments and having a systemic disease such as diabetes mellitus and thyroiditis were excluded. Demographic features were recorded and peripheral blood samples were taken from all participants to study serum whole blood count, creatinine, and C-reactive protein (CRP).

Results

Fifty patients with localized vitiligo, 43 patients with generalized vitiligo, and 50 healthy volunteers were enrolled in the study. Neutrophil to lymphocyte ratio and serum CRP levels were significantly higher in patients who have generalized vitiligo than those with localized vitiligo and healthy controls. However, there was no significant difference regarding neutrophil to lymphocyte ratio (NLR) and CRP between localized vitiligo and control groups.

Conclusions

Patients with generalized vitiligo seem to have increased systemic inflammation compared with localized vitiligo and control subjects in our cohort. To the best of our knowledge, this is the first study in the literature showing increased NLR values in generalized vitiligo patients. Further studies with cardiovascular disease markers are required to elicit this association better.

Autoimmune skin diseases and the metabolic syndrome

The metabolic syndrome represents an important association of cutaneous maladies with cardiovascular illnesses. Chronic inflammation, shared risk factors (ie, smoking and alcohol consumption), treatment (ie, immunosuppressive agents and drugs that alter the lipid profile), and shared genetic risk loci have been proposed to the cause metabolic syndrome and cardiovascular morbidity of autoimmune diseases. There are many possible inflammatory mediators that are suggested to play a role in insulin resistance pathogenesis, such as tumor necrosis factor-α, interleukin-6, leptin, and adiponectin. These mediators are also abnormal in autoimmune skin disorders. We discuss several autoimmune skin diseases, connective tissue diseases, bullous diseases, vitiligo, psoriasis, lichen planus, chronic urticaria, and atopic dermatitis.

Correlation between Serum Homocysteine and Vitiligo Area Scoring Index

BACKGROUND

Vitiligo is a chronic skin disorder. White macules caused by melanocyte destruction is a characteristic finding that cosmetically disturbing. Until recently, pathogenesis of vitiligo is still unclear. The role of homocysteine in vitiligo is mentioned in previous studies thus it is probable that it can be a biomarker to determine vitiligo severity.

AIM

To determine correlation between serum homocysteine and vitiligo area Scoring Index (VASI).

SUBJECT AND METHOD

This was a cross-sectional analytic study which involved 30 vitiligo patients that were diagnosed by clinical and Wood's lamp examinations then VASI score was determined and same numbers of control. We conducted blood sampling and measurement of serum homocysteine level to the patients.

RESULTS

There is no significant correlation between serum homocysteine and VASI score (p = 0.133, r = 0.281), family history (p = 0.706), and duration of vitiligo (p = 0.993, r = 0.002). There is no significant difference between serum homocysteine in vitiligo patients and controls (p = 0.905). There is a correlation between serum homocysteine with gender (p = 0.001) and age (p = 0.036; r = 0.385) in vitiligo patient.

CONCLUSION

There is no significant correlation between serum homocysteine and VASI score, family history, and duration of vitiligo. There is no significant difference between serum homocysteine in vitiligo patients and controls. There is a correlation between serum homocysteine with gender and age in vitiligo patient.

Usefulness of ischemia-modified albumin in predicting oxidative stress in patients with vitiligo

Aim: To investigate the emphasis of oxidative stress in the pathogenesis of vitiligo through an evaluation of ischemia-modified albumin (IMA). Results/methodology: IMA was of higher statistical significance in patients than in the control group (IMA: 0.57 ± 0.2 vs 0.52 ± 0.2 ΔABSU; p < 0.0001). IMA (p < 0.0001; OR: 8.9; 95% CI = 3.1–26.1) was found as an independent predictor of oxidative stress. Increases in affected body surface area and age were found to be independent risk factors for IMA. The sensitivity, specificity and positive and negative predictive values and capacity of IMA were higher than other studied biomarkers. Discussion/conclusion: IMA can be detected in the condition of oxidative stress in vitiligo; it has great potential as a biomarker of said condition, when compared with other studied biomarkers.

A Practical Approach to the Diagnosis and Treatment of Vitiligo in Children

Vitiligo is a common inflammatory skin disease with a worldwide prevalence of 0.5% to 2.0% of the population. In the pediatric population, the exact prevalence of vitiligo is unknown, although many studies state that most cases of vitiligo are acquired early in life. The disease is disfiguring, with a major psychological impact on children and their parents. Half of vitiligo cases have a childhood onset, needing thus a treatment approach that will minimize treatment side effects while avoiding psychological impacts. Management of vitiligo should take into account several factors, including extension, psychological impact, and possible associations with other autoimmune diseases. This review discusses the epidemiology of vitiligo and outlines the various clinical presentations associated with the disorder and their differential diagnosis. In addition, the pathophysiology and genetic determinants, the psychological impact of vitiligo, and management strategies are reviewed.

Serum Homocysteine and Total Antioxidant Status in Vitiligo: A Case Control Study in Indian Population

BACKGROUND

Oxidative stress is considered as an initial pathogenic event in melanocyte destruction. These free radicals are scavenged by antioxidants, whose sum of activity in serum is measured by total antioxidant status (TAS). In addition, homocysteine (Hcy) may mediate melanocyte destruction via increased oxidative damage. However, previous studies investigating these parameters in vitiligo provide equivocal results.

AIMS

To study and compare serum Hcy and TAS levels in vitiligo patients with controls and also to correlate these parameters with the various disease characteristics. The present study further looked into any correlation between serum Hcy and TAS in vitiligo.

MATERIALS AND METHODS

A case control study was conducted on 82 vitiligo patients and 83 controls aged 18-45 years after excluding factors which could potentially alter serum Hcy or TAS levels. Disease characteristics were studied and blood samples were obtained for measuring serum Hcy and TAS levels.

RESULTS

TAS levels were lower in vitiligo patients than controls (1.79 ± 0.51 vs. 2.16 ± 0.63 mmol/L; P < 0.001) and had a negative correlation with disease activity (r = -0.410, P < 0.001). However, serum Hcy levels were comparable between vitiligo patients (18.68 ± 9.90 μmol/L) and controls (20.21 ± 13.39 μmol/L) (P = 0.406). No significant correlation was found between serum Hcy and serum TAS levels.

CONCLUSIONS

Serum TAS may be further investigated to establish its role as biomarker for vitiligo since its levels also correlate with disease activity. However, serum Hcy may not be a reliable marker in Indian population probably because of differences in dietary habits.

Alternative Systemic Treatments for Vitiligo: A Review

Vitiligo is a common, acquired disorder of skin pigmentation that can significantly impact quality of life. It often represents a therapeutic challenge, which has resulted in interest in alternative treatments such as herbal and vitamin supplements. In this review, we provide an overview of the most commonly studied complementary agents, describe proposed mechanisms of action, identify potential adverse effects, and discuss the primary evidence supporting their use. Our discussion focuses on L-phenylalanine, Polypodium leucotomos, khellin, Ginkgo biloba, and vitamins and minerals, including vitamins B12, C, and E, folic acid, and zinc used as monotherapy or in combination with other treatments for the management of vitiligo.

A review of vitamin B12 in dermatology

Vitamin B12, also known as cobalamin, is a water-soluble vitamin that is important in the hematological and nervous systems, and it has a complex relationship with the skin. Altered cobalamin levels can lead to dermatological manifestations, which may indicate a deficiency or excess of this vitamin. The biochemistry and metabolism of cobalamin is complex, and diseases can be associated with alterations of this metabolic pathway. The cutaneous manifestations of cobalamin deficiency include hyperpigmentation (most commonly); hair and nail changes; and oral changes, including glossitis. Additionally, several dermatologic conditions, including vitiligo, aphthous stomatitis, atopic dermatitis, and acne are related to cobalamin excess or deficiency. The cutaneous complications of cobalamin therapy include acne, rosacea, and allergic site reactions, or anaphylaxis with cobalamin injections. As cobalt is a component of cobalamin, patients with cobalt sensitivity have been reported to have cutaneous manifestations when receiving cobalamin replacement therapy.

Vitiligo as a systemic disease

Vitiligo is an acquired depigmentary skin disorder of unknown etiology. Vitiligo is not only a disease of melanocytes of the skin. Human melanocytes are derived from the neural crest and are located on various parts of the body. The involvement of skin melanocytes is the most visible one, but a systemic involvement of melanocytes can be observed. Some types of vitiligo (nonsegmental vitiligo) may also be associated with various diseases, mainly with autoimmune pathogenesis. Vitiligo represents a spectrum of many different disorders with different etiologies and pathogeneses, causing a common phenotype: the loss of melanocytes and/or their products. This phenotype is always consistent with a systemic involvement.