Vitiligo is the most common acquired disorder of skin depigmentation, affecting approximately 1%-2% of the global population. It is characterized by the selective destruction of melanocytes, leading to depigmented macules or patches on the skin and mucosa. Though it is not a life-threatening condition, it significantly affects the psychological and social well-being of patients due to its disfiguring appearance, particularly in darker-skinned individuals. The peak incidence of vitiligo is observed in the second and third decades of life, though it can manifest at any age [1].

The etiology of vitiligo remains complex and multifactorial. Several theories have been proposed, including autoimmune destruction of melanocytes, genetic predisposition, oxidative stress, neurogenic factors, and environmental triggers [2]. The autoimmune hypothesis is widely accepted, supported by the presence of melanocyte-specific autoantibodies and the association of vitiligo with other autoimmune diseases such as autoimmune thyroiditis, diabetes mellitus, and Addison’s disease [3]. Studies indicate that up to 30% of vitiligo patients have a family history of the disease, suggesting a genetic component in its pathogenesis [4]. Genetic studies have identified several susceptibility loci linked to immune regulation and melanocyte function, further supporting the polygenic nature of vitiligo [5].

Vitiligo is clinically classified into non-segmental vitiligo (NSV), segmental vitiligo (SV), and mixed vitiligo. NSV is the most common type and is characterized by symmetrical depigmented macules that progress over time. SV, in contrast, presents as unilateral lesions following a dermatomal distribution and tends to have a stable course [6]. Mixed vitiligo involves features of both NSV and SV. The disease progression is unpredictable, with periods of rapid depigmentation followed by stability or even spontaneous repigmentation in some cases [7].

In addition to its autoimmune associations, vitiligo has been linked to endocrine disorders, particularly those involving the thyroid gland. Studies suggest that patients with vitiligo have a higher prevalence of autoimmune thyroid diseases such as Hashimoto’s thyroiditis and Graves’ disease, necessitating regular thyroid function screening [8]. Similarly, vitiligo has been associated with diabetes mellitus, with studies showing increased fasting glucose levels and insulin resistance in affected individuals [9]. Addison’s disease, an autoimmune disorder affecting the adrenal glands, has also been reported in vitiligo patients, further supporting the autoimmune hypothesis [10].

Given the increasing recognition of vitiligo as an autoimmune disorder with systemic associations, there is a growing need to assess its clinicodemographic profile and endocrinological associations. This study aims to analyze the clinical characteristics of vitiligo patients and evaluate their association with diabetes mellitus, thyroid dysfunction, and Addison’s disease. By identifying these associations, we hope to emphasize the importance of screening for endocrine disorders in vitiligo patients, facilitating early diagnosis and management.

This hospital-based cross-sectional observational study was conducted at the Department of Skin & VD, M.K.C.G Medical College and Hospital, from October 2019 to August 2021. A total of 100 clinically diagnosed vitiligo patients attending the outpatient department were included in the study. Patients were selected based on predefined inclusion and exclusion criteria. The inclusion criteria comprised all clinically diagnosed vitiligo patients, while the exclusion criteria included patients with other causes of depigmentation, those who had received prior vitiligo treatment, pregnant and lactating women, children under five years of age, and individuals with known endocrinopathies.

Data collection involved obtaining a detailed history, including demographic details, duration of disease, family history, presence of comorbid conditions, and lifestyle factors. A thorough cutaneous and systemic examination was conducted for each patient, assessing the type and extent of vitiligo, presence of leukotrichia, and Koebner’s phenomenon. The severity of vitiligo was graded using the Vitiligo Disease Activity (VIDA) score. Dermoscopic evaluation was performed to differentiate vitiligo from other hypopigmentary disorders.

Laboratory investigations were conducted to evaluate the association between vitiligo and endocrine dysfunctions. Thyroid function tests (T3, T4, and TSH), fasting and postprandial blood glucose levels, and morning serum cortisol levels were measured. Serum cortisol estimation was performed at 8 AM as a screening test for adrenal insufficiency, with confirmatory testing done where required. The thyroid profile was analyzed using an electrochemiluminescence immunoassay (ECLIA) method, while blood glucose levels were estimated using the glucose oxidase-peroxidase (GOD-POD) method.

Statistical analysis was performed using SPSS software version 21. Descriptive statistics were expressed as mean and standard deviation for continuous variables, while categorical data were presented as frequencies and percentages. Associations between variables were analyzed using Fisher’s exact test and Pearson’s chi-squared test, with a p-value of less than 0.05 considered statistically significant.

The study included 100 patients with vitiligo, with a slight male predominance (51%) over females (49%). The most commonly affected age group was 21-30 years (26%), followed by 31-40 years (22%). The lowest prevalence was observed in individuals older than 50 years (12%).

Table 1: Age and Gender Distribution of Vitiligo Patients

Among the different clinical types of vitiligo, vitiligo vulgaris was the most common presentation (51%), followed by focal vitiligo (31%) and acrofacial vitiligo (13%). Segmental vitiligo was observed in only 3% of cases, while lip vitiligo accounted for 2%.

Table 2: Type of Vitiligo in Study Population

Vitiligo lesions in this study were most frequently observed on the lower limbs, affecting 73% of patients. The face was the second most common site (32%), followed by the trunk (29%) and upper limbs (29%). The predilection for extremities aligns with previous studies, suggesting areas subjected to friction and minor trauma may be more prone to depigmentation. This distribution pattern supports the Koebner phenomenon, where vitiligo lesions develop in areas of repeated trauma

A family history of vitiligo was associated with an increased risk of endocrine disorders. Among patients with a family history, 5% had diabetes mellitus, 8% had thyroid dysfunction, and 2% had Addison’s disease (figure 2). In contrast, in patients without a family history, the prevalence was lower (2%, 3%, and 1%, respectively).

The majority of patients belonged to the middle socioeconomic class (59%), followed by the lower class (33%), with only 8% from the upper class. In terms of geographic distribution, 70% of the study participants were from urban areas, while 30% were from rural regions. The higher prevalence in urban populations may be attributed to better healthcare accessibility and increased awareness of vitiligo.

Table 3: Socioeconomic and Geographic Distribution

The study assessed the association between vitiligo and endocrine dysfunctions. Abnormal thyroid function tests were found in 11% of cases, with hypothyroidism being the most common abnormality (6%). Diabetes mellitus was present in 7% of patients, while Addison’s disease was observed in 3% of cases. A significant association was found between vitiligo and thyroid dysfunction, particularly in female patients (p=0.02).

Table 4: Presence of Endocrine Disorders in Vitiligo Patients

Endocrine dysfunction was more prevalent among patients with longer disease duration. Among patients with less than one year of vitiligo, only 2% had diabetes mellitus, 3% had thyroid dysfunction, and 1% had Addison’s disease. These percentages increased significantly in patients with 5 or more years of vitiligo (7%, 11%, and 3%, respectively).

The findings of this study reinforce the existing literature on the association between vitiligo and endocrine disorders. Our study identified a significant relationship between vitiligo and thyroid dysfunction, particularly hypothyroidism, in 11% of the patients, which aligns with previous research indicating a higher prevalence of autoimmune thyroid disease in vitiligo patients [11]. The presence of thyroid dysfunction was notably higher among females, a trend also observed in earlier studies emphasizing the greater predisposition of women to autoimmune thyroiditis [12]. This supports the need for routine thyroid function screening in vitiligo patients, particularly females.

The study also highlighted a notable prevalence of diabetes mellitus in vitiligo patients (7%). Research suggests that vitiligo patients may exhibit insulin resistance, increasing their susceptibility to type 2 diabetes mellitus [13]. Furthermore, studies have shown that shared genetic and autoimmune mechanisms might explain the co-occurrence of these conditions, with HLA and non-HLA genes playing a role in their pathogenesis [14]. These findings indicate that dermatologists and endocrinologists should collaborate to ensure early detection and management of diabetes in vitiligo patients.

Addison’s disease was observed in 3% of patients, consistent with reports describing a link between vitiligo and adrenal insufficiency [15]. Addison’s disease, an autoimmune disorder affecting the adrenal glands, shares common immunopathogenic pathways with vitiligo, leading to the destruction of melanocytes and adrenal cortical cells [16]. Screening for adrenal insufficiency in vitiligo patients with unexplained fatigue or hyperpigmentation is recommended, as early diagnosis can prevent life-threatening adrenal crises.

In terms of clinicodemographic characteristics, the study found that vitiligo was most prevalent in individuals aged 21-30 years (26%), which is comparable to other studies reporting the peak onset in young adulthood [17]. The mean age of onset was 32.92±14.69 years, reinforcing the notion that vitiligo frequently manifests during reproductive years. Additionally, a slight male predominance was noted (51% male, 49% female), though previous studies have reported variable gender distributions, likely influenced by cultural and healthcare-seeking behaviors [18].

Socioeconomic and geographic distribution patterns in the study revealed that 70% of patients were from urban areas, which may reflect better healthcare access and awareness. The predominance of patients from middle-class backgrounds (59%) suggests that vitiligo affects individuals across all socioeconomic strata, although financial constraints may impact treatment adherence [19].

Overall, our study underscores the need for a multidisciplinary approach in vitiligo management, integrating dermatological care with endocrinological assessment. Given the strong association between vitiligo and autoimmune conditions, regular screening for thyroid dysfunction, diabetes mellitus, and adrenal insufficiency is warranted. Future longitudinal studies with larger sample sizes are needed to establish causality and explore genetic markers that predispose individuals to these comorbidities [20].

Vitiligo is associated with a significant burden of endocrine dysfunctions, particularly hypothyroidism and diabetes mellitus. Screening for endocrine abnormalities in vitiligo patients is crucial for early intervention and improved clinical outcomes. Further studies with larger sample sizes and longitudinal follow-ups are needed to establish a causal relationship between vitiligo and endocrinopathies.

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