Incidence of lichen planus and subsequent mortality in finnish women

The incidence pattern of lichen planus (LP) and LP-related mortality are unknown. The aim of this study was to assess these factors, based on Finnish nation-wide registry data including 13,378 women with LP diagnosed during 1969 to 2012. The incidence rate for LP in 2003 to 2012 was 28 per 100,000 woman-years age-adjusted to the European Standard Population. Mortality was assessed using the standardized mortality ratio (SMR) with national mortality rates as the re-ference. All-cause mortality was increased (SMR 1.07, 95% confidence interval (95% CI) 1.02–1.11), with excess mortality from Hodgkin lymphoma (SMR 6.73, 95% CI 1.83–17.2), non-Hodgkin lymphoma (SMR 1.68, 95% CI 1.11–2.44), cancer of the oral cavity (SMR 10.5, 95% CI 5.99–17.0), cancer of the tongue (SMR 7.25, 95% CI 3.13–14.3), infections (SMR 1.78, 95% CI 1.14–2.64), respiratory diseases (SMR 1.31, 95% CI 1.07–1.57), and diseases of the digestive sys-tem (SMR 1.39, 95% CI 1.09–1.75). In conclusion, LP is a common disease and patients seem to have an im-paired long-term prognosis.