Estimating the burden of vitiligo: a systematic review and modelling study.

BACKGROUND: Vitiligo is a chronic autoimmune disease characterised by depigmented skin patches, which can pose substantial psychosocial challenges particularly in individuals with dark skin tones. Despite its impact on quality of life, there is an absence of standardised global epidemiological data. We sought to address this gap with the present study. METHODS: In this study we did a systematic review and modelling analysis to estimate the global, regional, and national prevalence and incidence of vitiligo. We did a comprehensive search of nine digital libraries (PubMed, Embase, Web of Science, Scientific Electronic Library Online, KCI Korean Journal Database, Russian Science Citation Index, Western Pacific Region Index Medicus, Informit, and Health Research and Development Information Network) from inception up to May 25, 2023. We included cross-sectional or cohort studies reporting the incidence rate or prevalence of vitiligo, or data from which incidence rate or prevalence could be calculated, in the general population of a country or area of a country. Summary estimate data were extracted. A main outcome was to estimate the worldwide, regional, and country-specific lifetime prevalence of vitiligo diagnosed by physicians or dermatologists among the general population and in adults and children (as per age groups defined in included studies). We used a Bayesian hierarchical linear mixed model to estimate prevalence, and calculated number of affected individuals using the UN population structure in 2022. In estimating lifetime prevalence, studies reporting point or period prevalence were excluded. Our other main outcome was to estimate incidence rates of vitiligo, but due to a small number of studies, the data on incidence were presented in a descriptive summary. This study was registered on PROSPERO, CRD42023390433. FINDINGS: Our search identified 22 192 records, of which 90 studies met our inclusion criteria. Of these studies, six focused on the incidence of vitiligo, 79 reported on the prevalence of vitiligo, and five provided data on both incidence and prevalence. 71 studies reported on lifetime prevalence. In the most recent years studied, incidence rates in the general population ranged from 24·7 cases (95% CI 24·3-25·2) per 100 000 person-years in South Korea in 2019, to 61·0 cases (60·6-61·4) in the USA in 2017. In individual studies, incidence rates showed an increasing trend over the periods studied. The global lifetime prevalence of vitiligo diagnosed by a physician or dermatologist was estimated at 0·36% (95% credible interval [CrI] 0·24-0·54) in the general population (28·5 million people [95% CrI 18·9-42·6]), 0·67% (0·43-1·07) in the adult population (37·1 million adults [23·9-58·9]), and 0·24% (0·16-0·37) in the child population (5·8 million children [3·8-8·9]). Vitiligo prevalence was higher in adults than in children across all regions. Central Europe and south Asia reported the highest prevalence (0·52% [0·28-1·07] and 0·52% [0·33-0·82], respectively, in the general population). INTERPRETATION: This study highlights the need for standardised epidemiological data collection globally to inform public health policies and improve vitiligo diagnosis and management. Emphasis on the impact on individuals with darker skin tones is crucial to reducing stigma and improving quality of life. Furthermore, our study highlights the need to conduct more research in regions and populations that have been historically under-represented, to effectively address the worldwide burden of vitiligo. FUNDING: None.

Prevalence and incidence of comorbid diseases and mortality risk associated with lichen planopilaris: a Korean nationwide population-based study.

BACKGROUND: Various comorbid diseases have been reported in patients with lichen planopilaris (LPP); however, data regarding the risks of incident diseases and mortality are lacking. OBJECTIVES: To investigate the risks of incident diseases and mortality associated with LPP. METHODS: This was a retrospective nationwide population-based study, using data from the National Health Insurance Service Database of Korea from 2002 to 2019. Patients aged ≥ 18 years with three or more documented medical visits for LPP were included. The adjusted hazard ratios (aHRs) for incident disease outcomes and mortality were compared with 1 : 20 age-, sex-, insurance type- and income-level-matched controls. RESULTS: In total, 2026 patients with LPP and 40 520 controls were analysed. The risks of incident systemic lupus erythematosus [aHR 1.91, 95% confidence interval (CI) 1.21-3.03], psoriasis (aHR 3.42, 95% CI 2.83-4.14), rheumatoid arthritis (aHR 1.39, 95% CI 1.19-1.63), lichen planus (aHR, 10.07, 95% CI 7.17-14.15), atopic dermatitis (aHR 2.15, 95% CI 1.90-2.44), allergic rhinitis (aHR 1.29, 95% CI 1.13-1.49), thyroid diseases (hyperthyroidism: aHR 1.42, 95% CI 1.14-1.77, hypothyroidism aHR 1.19 95% CI 1.01-1.41, and thyroiditis: aHR, 1.35, 95% CI 1.08-1.69), nonmelanoma skin cancer (aHR 2.33, 95% CI 1.00-5.44) and vitamin D deficiency (aHR 1.23, 95% CI 1.03-1.47) were higher in patients with LPP. Patients with LPP had a higher mortality rate than controls (aHR 1.30, 95% CI 1.04-1.61), although the risk was not significant after adjusting for comorbidities (aHR 1.08, 95% CI 0.87-1.34). CONCLUSIONS: Patients with LPP had a higher risk of various diseases following LPP diagnosis. Close follow-up is needed to optimize comprehensive patient care.

Epidemiology and comorbidity of hidradenitis suppurativa in Korea for 17 years: A nationwide population-based cohort study.

Hidradenitis suppurativa (HS) is associated with various metabolic and autoimmune diseases. The epidemiology has been analyzed in various studies worldwide. However, epidemiological data on HS for Asian populations are limited. This study aimed to analyze the change in the prevalence and incidence of HS over 17 years in South Korea using the Korean National Health Insurance Service (NHIS) database. This study also evaluated the comorbidities in patients with HS. Population-based data from the NHIS database of Korea were obtained between January 2003 and December 2019. Odds ratios were estimated to determine the association between comorbidities and HS during the study period. Hazard ratios for the risk of incident comorbidities in patients with HS were obtained using the multivariable Cox proportional hazard analysis. This study included 45 511 patients with HS and 910 220 controls matched for age, sex, insurance type, and income level. The incidence rate of HS per 1 000 000 person-years in Korea increased from 11.69 in 2003 to 78.78 in 2019. The annual prevalence per 1 000 000 people also increased from 34.68 in 2003 to 140.10 in 2019, showing a similar trend. Many comorbidities, including atopic, metabolic and end-organ, autoimmune/inflammatory, and psychiatric diseases were associated with HS at baseline. In many diseases, the risk of incident comorbidities in patients with HS was higher than that in controls. The incidence and prevalence of HS in Korea have increased over the past 17 years. Various comorbidities, including allergic diseases, hypertension, diabetes mellitus, dyslipidemia, myocardial infarction, chronic hepatitis and cirrhosis, chronic kidney disease, inflammatory bowel diseases, rheumatoid arthritis, vitamin D deficiency, and psychiatric diseases, were associated with HS. Physicians need to keep in mind and closely monitor these comorbidities in patients with HS.

Comparison of the Efficacy and Safety of Biologics (Secukinumab, Ustekinumab, and Guselkumab) for the Treatment of Moderate-to-Severe Psoriasis: Real-World Data from a Single Korean Center.

Biologics are important treatment options for psoriasis; however, direct comparison of their efficacy, safety, and drug survival is insufficient in clinical practice. This retrospective single-center study aimed to compare the efficacy, safety, and drug survival of three commonly used psoriasis biologics (secukinumab, ustekinumab, and guselkumab) and identify the factors affecting drug survival in actual clinics in Korea. We enrolled 111 patients with moderate to severe psoriasis and for at least 56 weeks of follow-up; among these, 27, 23, and 61 were administered secukinumab, ustekinumab, and guselkumab, respectively. All groups were comparable with respect to their baseline characteristics. Secukinumab showed a rapid response, and guselkumab was superior in terms of a long-term response and complete remission compared with other biologics, while ustekinumab showed a lower efficacy compared with other biologics. All three biologics had a favorable and similar safety profile; however, allergic reactions and latent tuberculosis were more common with secukinumab and ustekinumab, respectively. Guselkumab was the most sustained biologic, and the survival rates of secukinumab and ustekinumab were similar. Drug survival was remarkably shorter in female patients and those with hypertension. Introduction of new biologics emerged as a negative factor for drug survival in clinical settings.