Relevance of congenital melanocytic naevi in vitiligo

Epidemiology of Vitiligo - A Dual Population-Based Approach

Background

Most epidemiological data on vitiligo refer to selected environments or focus on the prevalence of comorbidity unrelated to the population.

Objective

Aim of the study was to gain robust representative prevalence data on vitiligo and on associated dermatologic comorbidity in the German adult population.

Methods

A dual population-based approach was applied with 1) primary data obtained between 2004 and 2014 from dermatological exams in the general working population; 2) claims data from a large German statutory health insurance, reference year 2010.

Results

In the working cohort (N = 121,783; 57% male; mean age 43 years), the prevalence of vitiligo was 0.77% (0.84% in men; 0.67% in women). In the claims data (N = 1,619,678; 38% male; mean age 46 years), prevalence was 0.17% (0.14% in men; 0.18% in women). In the working cohort, vitiligo was significantly more common in people with fair skin type, ephelides and port-wine stains and less common in people with acne and solar lentigines. In the claims data, vitiligo was associated with a variety of skin conditions, eg, atopic dermatitis, psoriasis and alopecia areata.

Conclusion

The resulting discrepancy of claims vs primary data between 0.17% and 0.77% indicates the most probable spectrum of vitiligo prevalence in Germany. It is more frequently observed in clinical exams than recorded in claims data, indicating a marked proportion of people seeking no medical help. Such nonattendance may result from the fact that many treatment options do not provide satisfying benefits to the patients.

Distribution Patterns (7B Rule) and Characteristics of Large Congenital Melanocytic Nevi: A Retrospective Cohort Study in China

Large congenital melanocytic nevus has a high risk of malignancy. However, few studies have summarized its characteristics, treatments, outcomes and malignancy incidence in Chinese patients. This paper reviews a retrospective cohort study evaluating 1,171 patients from Shanghai Ninth People's Hospital between 1 January 1989 and 31 August 2019 using electronic medical records and phone calls to collect clinical and pathological data in which 133 patients were diagnosed with a large congenital melanocytic nevus. Three patients relapsed, and none developed melanoma among the qualified patients. Besides, a new “7B” rule for distribution patterns of large congenital melanocytic nevi was proposed, including bonce, bolero, back, bathing trunk, breast/belly, body extremity, and body. The most common distribution pattern of large congenital melanocytic nevi was bonce, and all blue nevi distributed as bonce. Statistical analysis showed a significant difference (P = 0.0249) in the “7B” patterns between the melanocytic nevus and the neuronevus. In conclusion, the malignancy rate of large congenital melanocytic nevi is much lower in China than in other regions and people of other races. The pathology of large congenital melanocytic nevus may decide its “7B” distribution pattern.

Pigmentation Traits, Sun Exposure, and Risk of Incident Vitiligo in Women

Vitiligo is the most common cutaneous depigmentation disorder worldwide, yet little is known about specific risk factors for disease development. Using data from the Nurses' Health Study, a prospective cohort study of 51,337 white women, we examined the associations between (i) pigmentary traits and (ii) reactions to sun exposure and risk of incident vitiligo. Nurses' Health Study participants responded to a question about clinician-diagnosed vitiligo and year of diagnosis (2001 or before, 2002-2005, 2006-2009, 2010-2011, or 2012+). We used Cox proportional hazards regression models to estimate the multivariate-adjusted hazard ratios and 95% confidence intervals of incident vitiligo associated with exposures variables, adjusting for potential confounders. We documented 271 cases of incident vitiligo over 835,594 person-years. Vitiligo risk was higher in women who had at least one mole larger than 3 mm in diameter on their left arms (hazard ratio = 1.37, 95% confidence interval = 1.02-1.83). Additionally, vitiligo risk was higher among women with better tanning ability (hazard ratio = 2.59, 95% confidence interval = 1.21-5.54) and in women who experienced at least one blistering sunburn (hazard ratio = 2.17, 95% confidence interval = 1.15-4.10). In this study, upper extremity moles, a higher ability to achieve a tan, and history of a blistering sunburn were associated with a higher risk of developing vitiligo in a population of white women.