European Journal of Cardiovascular Medicine

The skin is the largest organ of the human body and, histologically, it consists of three primary layers: the epidermis, dermis, and hypodermis. The epidermis is further subdivided into five layers—stratum basale (the deepest layer), stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum (the most superficial layer) [1]. The mechanism of skin pigmentation is primarily regulated by keratinocytes and melanocytes located in the basal layer of the epidermis [2].

Melanocytes originate embryologically from neural crest cells, and their migration to the skin and hair follicles is governed by several transcription factors and signaling pathways [3]. These cells produce a brown pigment known as melanin, which serves to protect the skin from potentially harmful ultraviolet (UV) radiation in sunlight. Exposure to UV light can induce DNA damage in keratinocytes [4,5], which leads to overexpression of the p53 gene, subsequently increasing the transcription of the proopiomelanocortin (POMC) gene and enhancing the synthesis of POMC protein. This protein is cleaved into adrenocorticotropic hormone (ACTH) and alpha-melanocyte-stimulating hormone (α-MSH).

α-MSH binds to the melanocortin 1 receptor (MC1R), a G-protein-coupled receptor on melanocytes, activating adenylate cyclase and the mitogen-activated protein (MAP) kinase pathway. This cascade stimulates the production of eumelanin, tyrosinase, and tyrosinase-related proteins. Tyrosinase, the rate-limiting enzyme in melanogenesis, converts tyrosine into DOPA and then into melanin. The produced melanin is packaged into melanosomes—lysosome-like organelles—which are then transferred to keratinocytes via protease-activated receptors. As keratinocytes migrate from the basal layer to the surface, they carry melanosomes with them, contributing to the visible pigmentation of the skin.

There are two main types of melanin: pheomelanin and eumelanin. Pheomelanin predominates in fair-skinned individuals, while eumelanin is more abundant in dark-skinned individuals. Eumelanin offers greater protection against UV radiation than pheomelanin [6–10].

Hypopigmentation refers to a reduction in melanin, resulting in areas of skin that are lighter than the surrounding normal skin. Common causes include pityriasis Alba, pityriasis versicolor, vitiligo, seborrheic dermatitis, idiopathic guttate hypomelanosis, and atopic dermatitis [11]. Hypopigmented skin lesions are among the most frequently encountered dermatological concerns in clinical practice. One of the primary reasons for seeking medical attention is cosmetic disfigurement, which can lead to psychological stress and social stigma, especially in individuals with darker skin tones. The increasing prevalence of pediatric skin diseases significantly contributes to morbidity in children; however, epidemiological data on pediatric dermatoses remain limited and are derived from only a few published studies

Study Design: This was an institution-based, descriptive, cross-sectional study. Children presenting with hypopigmented lesions who fulfilled the inclusion criteria and whose parents provided informed consent were included in the study.

Study Setting and Timeline: The study was conducted in the Department of Dermatology, Medical College, and Kolkata. Recruitment of patients and data collection took place from January 2020 to March 2021. Data analysis and literature review were carried out between March 2021 and May 2021. Thesis writing and final submission were completed from June 2021 to August 2021.

Study Place: The proposed study was conducted in the outpatient and inpatient departments of the Department of Dermatology, Medical College and Hospital, Kolkata.

Study Period: January 2020 to March 2021.

Study Population: All pediatric patients attending the Dermatology Outpatient Department (OPD) of Medical College and Hospital, Kolkata were considered for inclusion in the study.

Sample Size: Based on records from previous years, approximately 100 children below 12 years of age were expected to be recruited during the study period.

Inclusion Criteria:

• Pediatric patients below 12 years of age
• Both male and female children
• Presence of hypopigmented skin lesions
• Attending the Dermatology Outpatient Department (OPD) of Medical College and Hospital, Kolkata
• Parents/guardians willing to provide informed consent

Exclusion Criteria:

• Parents or guardians of affected children who did not provide consent to participate in the study

Parameters to Be Studied:

Patient Particulars: Age, Sex, Residence of Parents, Occupation of Parents, Income of Parents. Complaints Of Patients: Hypopigmention, Itching, Pain, Decreased Sensation, Scaling, Cosmetic.

Important History:

• Aggravating /Relieving Factors( Food, Seasons, Trauma, Chemicals)
• Co-Morbidities (If Any)
• H/O Atopy In Patient
• Family History Of Atopy
• Drug History; H/O Mdt

Description of the Lesion:

• Primary and Secondary Lesion.
• Number of The Lesion
• Size of The Lesion
• Shape of The Lesion
• Margin of The Lesion
• Site of The Lesion

Involvement of Other Sites:

• Oral Mucosa / Scalp / Nail
• Histopathological Examination In Selected Cases.(If Needed)
• Blood Tests Investigations (If Needed).

Study Tools:

• OPD Admission Register, OPD Tickets.
• Informed Consent Form.
• Case Record From.
• Journals and Text Books.
• Digital Image Recording System.
• Histopathology Slides in Selected Cases.
• Blood Reports and Other Reports (If Required).

Statistical Analysis: Descriptive statistics were done for analyzing, summarizing the data on different variables. Comparison among subgroups such as gender and age groups was performed by chisquare test for categorical data and unpaired t-test for continuous data. P value ≤0.05 will be considered significant. Microsoft excel was used for drawing graph.

Table 1: Distribution of Cases According To Provisional Diagnosis

Table 2: Comparison of Provisional Diagnosis by Religion

Table 3: Comparison of Provisional Diagnosis between Urban and Rural Populations

Table 4: Distribution of Symptoms (Cosmetic Concern, Itching, Loss of Sensation) In Different Provisional Diagnoses

Table 5: Distribution of Lesions By Site (Face, Trunk, Extremities) In Different Provisional Diagnoses

In this study, the most frequent provisional diagnosis among patients presenting with hypopigmented skin lesions was early vitiligo, accounting for 25% of cases. This was followed by pityriasis versicolor (15%), seborrheic dermatitis (12%), and post-inflammatory hypopigmentation (12%). Other less common diagnoses included xerotic dermatitis (8%), atopic dermatitis (6%), idiopathic guttate hypomelanosis (5%), and polymorphous light eruption (PMLE) (4%). Rarely observed conditions were pityriasis alba (9%), nevus depigmentosus (2%), halo nevus (1%), and Hansen’s disease (1%). The overall distribution of these conditions was statistically significant (p < 0.00001).

When comparing the distribution between religious groups, early vitiligo was most common among Hindu patients (14 cases), followed by seborrheic dermatitis (8), post-inflammatory hypopigmentation (7), and pityriasis versicolor (5). Less frequent conditions included pityriasis alba (3), xerotic dermatitis (3), idiopathic guttate hypomelanosis (3), atopic dermatitis (2), PMLE (1), nevus depigmentosus (1), and halo nevus (1). Notably, there were no cases of Hansen’s disease among Hindu patients. Among Muslim patients, pityriasis versicolor (10) and early vitiligo (11) were most prevalent, followed by xerotic dermatitis (5) and seborrheic dermatitis (4). Other diagnoses included post-inflammatory hypopigmentation (5), atopic dermatitis (4), pityriasis alba (4), PMLE (3), idiopathic guttate hypomelanosis (2), nevus depigmentosus (1), and Hansen’s disease (1), while no cases of halo nevus were reported. Statistical analysis showed no significant association between religion and the type of hypopigmented skin disorder (p = 0.6984).

Analysis based on residence revealed that among urban patients, early vitiligo was most common (14 cases), followed by pityriasis versicolor (8), post-inflammatory hypopigmentation (8), xerotic dermatitis (5), and pityriasis alba (4). Other diagnoses included seborrheic dermatitis (4), idiopathic guttate hypomelanosis (2), and atopic dermatitis (2). No cases of PMLE, Hansen’s disease, nevus depigmentosus, or halo nevus were reported in this group. In rural patients, early vitiligo (11) and seborrheic dermatitis (8) were most frequent, followed by pityriasis versicolor (7), pityriasis alba (5), xerotic dermatitis (3), idiopathic guttate hypomelanosis (3), post-inflammatory hypopigmentation (4), atopic dermatitis (4), PMLE (4), nevus depigmentosus (2), halo nevus (1), and Hansen’s disease (1). No statistically significant difference was found between urban and rural populations regarding the pattern of hypopigmented skin disorders (p = 0.3447).

Presenting symptoms were categorized as cosmetic concern, itching, or sensory loss. Cosmetic concerns predominated in cases of early vitiligo (25), pityriasis alba (9), post-inflammatory hypopigmentation (12), idiopathic guttate hypomelanosis (5), nevus depigmentosus (2), halo nevus (1), and Hansen’s disease (1). Itching was most commonly reported in pityriasis versicolor (13), seborrheic dermatitis (11), and xerotic dermatitis (8). It was also noted in atopic dermatitis (6), PMLE (4), pityriasis alba (3), and post-inflammatory hypopigmentation (2), but was minimal or absent in other conditions. Loss of sensation was reported exclusively in Hansen’s disease (1), consistent with its clinical presentation. The association between presenting symptoms and diagnosis was statistically significant (p < 0.001), with cosmetic concerns predominating in depigmenting disorders and pruritus more common in inflammatory dermatoses.

Anatomical distribution of lesions was assessed across the face, trunk, and extremities. Pityriasis alba was exclusively localized to the face (9 cases). Pityriasis versicolor predominantly affected the trunk (15), followed by the extremities (4) and face (2). Seborrheic dermatitis involved both the face (6) and trunk (8), with no extremity involvement. Early vitiligo was widely distributed across the face (5), trunk (14), and extremities (9). Post-inflammatory hypopigmentation showed a predilection for the extremities (8), with fewer cases on the trunk (2) and face (2). PMLE (2) and atopic dermatitis (6) were more common on the extremities. Xerotic dermatitis (8 trunk, 3 extremities), idiopathic guttate hypomelanosis (2 trunk, 2 extremities), nevus depigmentosus (2 trunk), halo nevus (1 extremity), and Hansen’s disease (1 trunk) also demonstrated varied anatomical involvement. However, there was no statistically significant association between the site of lesions and specific diagnosis (p = 2.5844).

In this study, early vitiligo emerged as the predominant diagnosis among patients presenting with hypopigmented skin lesions, accounting for 25% of cases. This finding is consistent with prior epidemiological data; for example, Singh et al. (2017) identified vitiligo as the leading cause of hypopigmentation in their cohort, with a reported prevalence of approximately 27%, underscoring its global clinical relevance as a major pigmentary disorder [12]. The observed prevalence of pityriasis versicolor (15%) and seborrheic dermatitis (12%) in our cohort aligns with the findings of Boonchai and Jiamton (2013) and Kaur et al. (2015), who reported these as common etiologies of hypopigmented lesions, particularly in tropical regions where factors such as Malassezia proliferation and increased sebaceous gland activity are contributory [13,14].

Our analysis revealed no statistically significant differences in the distribution of hypopigmented disorders when stratified by religion or residential status (urban vs. rural). This mirrors the findings of Kumar et al. (2018), who suggested that environmental and genetic predispositions may have a greater influence on the manifestation of these conditions than sociocultural or demographic variables [15]. Although not statistically significant, the relatively higher prevalence of pityriasis versicolor among Muslim patients and seborrheic dermatitis among Hindu patients may reflect differences in hygiene practices, occupational exposures, or other lifestyle factors—a hypothesis supported by Choudhary and Dutta (2016) [16].

Symptomatically, cosmetic concerns were the predominant complaint among patients with early vitiligo, pityriasis alba, and post-inflammatory hypopigmentation. This trend is consistent with the psychosocial impact highlighted by Ongenae et al. (2006), who emphasized the substantial burden visible pigmentary disorders can have on patients’ quality of life [17]. In contrast, itching was more frequently reported in inflammatory dermatoses such as seborrheic dermatitis and pityriasis versicolor, corroborating the findings of Gupta and Mays (2001), who noted pruritus as a common symptom in both fungal and seborrheic conditions [18]. Notably, sensory loss was reported exclusively in the single case of Hansen’s disease, reflecting the classical neuropathic features extensively described in the literature, including a comprehensive review by Walker (2012) [19].

With regard to anatomical distribution, our findings revealed distinct site predilections: pityriasis ALBA was confined to the face, pityriasis versicolor predominantly affected the trunk, and early vitiligo demonstrated widespread involvement across the face, trunk, and extremities. These patterns are consistent with the clinical descriptions provided by Das and Mukhopadhyay (2014), who detailed site-specific manifestations that aid in the differential diagnosis of hypopigmented dermatoses [20]. Despite these patterns, statistical analysis showed no significant association between lesion site and diagnosis, which may be attributed to overlapping clinical presentations or limitations in sample size

This study highlights early vitiligo as the most prevalent cause of hypopigmented skin lesions, followed by pityriasis versicolor, seborrheic dermatitis, and post-inflammatory hypopigmentation. The distribution of these conditions showed no statistically significant differences across religious affiliations or between urban and rural populations. From a symptomatic perspective, cosmetic concerns were the predominant complaint in pigmentary disorders such as vitiligo, while pruritus was more commonly associated with inflammatory dermatoses like seborrheic dermatitis and pityriasis versicolor. Although lesion distribution patterns generally aligned with classical clinical presentations, no significant correlation was observed between the anatomical site of lesions and the specific diagnosis.

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