Background: Diffuse facial melanosis (DFM) is a common pigmentary disorder affecting individuals of all ages. Conditions in this category include pigmented contact dermatitis (PCD), lichen planus pigmentosus (LPP), and ashy dermatosis (AD), which fall under the umbrella term acquired dermal macular hyperpigmentation, as well as other diseases. These disorders impose a significant psychological burden and present a complex clinical challenge. Aim: This study aims to evaluate and correlate the clinical, dermoscopic, histopathological, and immunohistochemical patterns of acquired pigmentary DFM in patients older than 12 years. Methods: This descriptive cross-sectional study was conducted in the pigmentary clinic between August 2022 and January 2024. Patients above 12 years of age with DFM were enrolled, and evaluation was done by clinical, dermoscopic, histopathological, and immunohistochemical analysis. A statistical correlation was performed on the above findings. Results: A total of 110 patients, aged between 17 and 65 years, were included in the study. PCD was the most common disorder (31.82%), followed by LPP (26.36%), exogenous ochronosis, and AD. The most common medical conditions included nonalcoholic fatty liver disease (8.18%) and hypothyroidism (7.27%). Pigmentation was the chief complaint in all cases, followed by scaling and itching. Dermoscopy revealed features such as globules or dots of varied colors, a pseudoreticular pattern, pigment network, and pinkish hue across different types of melanoses. Specific patterns such as the owl’s-eye, hem-like, worm-like, and wagyu beef-like patterns were also noted. Histopathological analysis showed features of pigment incontinence, perivascular infiltrate, and increased basal pigmentation in most disorders. Immunohistochemical analysis revealed positivity for CD4, CD8, and Melan-A, which correlated with the histopathological findings. Limitations: These include selection bias and interobserver variability in dermoscopic and histopathological findings, as well as smaller sample sizes in some cases of facial melanosis, and limitations of immunohistochemical analysis. Conclusion: A combined approach involving clinical, dermoscopic, histopathological, and immunohistochemical diagnosis can aid in more accurate diagnosis of this challenging entity and a deeper understanding of its molecular pathology.
Background: Medical students, as future healthcare providers, play a key role in promoting photoprotection and skin cancer prevention. However, gaps in their own knowledge, attitudes, and practices regarding sun protection may limit their effectiveness in patient education. This study aimed to assess and compare these domains across different professional years. Objective: To evaluate and compare the knowledge, attitudes, and practices regarding photoprotection among medical students in the preclinical, paraclinical, and clinical years. Methods: A cross-sectional study was conducted among 404 undergraduate medical students at a tertiary-care medical college using a validated, self-administered questionnaire. Knowledge (15 items), attitudes (10 items; 5-point Likert scale), and practices (12 items) were assessed. Descriptive statistics, chi-square tests, one-way ANOVA, and logistic regression were used for analysis. Results: The mean knowledge score was 9.8 ± 3.2 out of 15 (65.3%), with only 42.6% achieving adequate knowledge (≥70%). Knowledge scores increased significantly across professional years (preclinical: 8.1, paraclinical: 9.7, clinical: 11.4; P < 0.001). Attitudes were generally positive (mean 3.6/5), but only 58.4% had strongly positive attitudes. Consistent sunscreen use was reported by 31.7% of users, correct application by 42.8% of users, and regular skin self-examination by 19.8% of users. Clinical-year students showed the highest rates of appropriate practices ( P < 0.001). Higher knowledge was associated with better attitudes [odds ratio (OR): 2.8] and practices (OR: 3.4) (both P < 0.001). Female students had significantly higher knowledge scores and sunscreen use than male students ( P < 0.001). Conclusion: While photoprotection knowledge, attitudes, and practices improve with advancing professional years, substantial gaps remain among medical students. Targeted educational interventions are needed early in medical training to enhance sun-safety awareness and behavior.
Vitiligo is a chronic autoimmune pigmentary disorder characterized by melanocyte destruction and progressive depigmentation, frequently associated with substantial psychosocial burden, particularly in individuals with skin of color. Despite recent advances in therapy, including topical ruxolitinib and emerging targeted immunomodulatory approaches, major limitations remain, including incomplete repigmentation, variable therapeutic response, relapse following treatment discontinuation, limited access to phototherapy, and challenges in treating extensive body surface areas. These gaps highlight the need for strategies that improve the localization, durability, and consistency of therapeutic exposure within depigmented lesions. Emerging biomaterial-based approaches, including hydrogels and nanoparticle delivery systems, offer promising opportunities to enhance localized retention and sustained release of topical therapeutics. Chitosan-based systems are particularly attractive due to their biocompatibility, electrostatic interaction with nucleic acids, mucoadhesive properties, and tunable physicochemical characteristics. Modified derivatives such as succinylated chitosan further expand opportunities to regulate hydration behavior, diffusion kinetics, and localized therapeutic retention. Localized nucleic acid delivery approaches, including siRNA and dsRNA-based systems, represent an additional translational strategy for targeted modulation of inflammatory pathways implicated in vitiligo pathogenesis. Chitosan polyplex nanoparticles may provide a platform for protecting nucleic acid cargo while improving localized transport and therapeutic delivery within the cutaneous microenvironment. This narrative review examines the translational potential of chitosan-based hydrogels, N-succinyl chitosan and nucleic acid nanoparticle systems in vitiligo, emphasizing precision topical delivery, skin of color considerations, and future biomaterial strategies aimed at improving repigmentation outcomes and reducing disease burden.
