Risk of skin cancer in psoriasis patients receiving long-term narrowband ultraviolet phototherapy: Results from a Taiwanese population-based cohort study.

BACKGROUND: Narrowband ultraviolet B (NB-UVB) phototherapy is a widely used treatment for various dermatoses. The risk of skin cancer following long-term NB-UVB phototherapy has rarely been explored in skin phototypes III-V. METHODS: We conducted a nationwide-matched cohort study and identified a total of 22 891 psoriasis patients starting NB-UVB phototherapy from the Taiwan National Health Insurance Database during the period 2000-2013. Cumulative incidences of skin cancers were compared between subjects receiving less than 90 UVB treatments (S-cohort, N = 13 260) and age- as well as propensity score-matched subjects receiving more than or equal to 90 UVB treatments (L-cohort, N = 3315). RESULTS: There were no significant differences in the overall cumulative incidences of skin cancers between the two cohorts (log-rank t test, P = 0.691) during the follow-up periods. The S-cohort had a significantly lower prevalence of actinic keratosis when compared with the L-cohort (0.54% vs 1.00%, P = 0.005). CONCLUSION: Long-term NB-UVB phototherapy does not increase skin cancer risk compared with short-term NB-UVB phototherapy in psoriasis patients with skin phototypes III-V.

Risk of inflammatory bowel disease in patients with rosacea: Results from a nationwide cohort study in Taiwan.

BACKGROUND: A link between rosacea and inflammatory bowel disease (IBD) has been proposed with unknown mechanisms. Epidemiologic evidence of this association needs to be examined. METHODS: In this nationwide cohort study, a total of 89,356 patients with rosacea and 178,712 matched patients without rosacea between 1997 and 2013 were identified in the Taiwanese National Health Insurance Research Database. Cumulative incidences of IBD were compared between these 2 cohorts. Frailty Cox proportional hazard model was used and subgroup analyses were conducted to examine the risk factors for IBD. RESULTS: The 15-year cumulative incidences of IBD were 0.036% (95% confidence interval [CI] 0.00%-1.57%) and 0.019% (95% CI 0.00%-0.83%) in rosacea and nonrosacea cohorts, respectively (P = .05). Rosacea (adjusted hazard ratio 1.94, 95% CI 1.04-3.63, P = .04) and male gender (adjusted hazard ratio 3.52, 95% CI 2.03-6.11, P < .01) were independently associated with IBD, after adjustment for major comorbidities. Multivariate subgroup analyses revealed consistent results. The incidence rates of IBD decreased with increasing antibiotic use in patients with rosacea, but without statistical significance. LIMITATION: Information related to lifestyle, diet, alcohol, and smoking was not included in the database. CONCLUSION: Patients with rosacea may have an increased risk of IBD.