Pia Halonen, Maija Jakobsson, Oskari Heikinheimo, Mika Gissler, Eero Pukkala
DOI: 10.2340/00015555-3664

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 nationwide 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 reference. 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 system (SMR 1.39, 95% CI 1.09–1.75). In conclusion, LP is a common disease and patients seem to have an impaired long-term prognosis.

Lichen planus is a skin disease that may affect many different cutaneous or mucous parts of the body in individuals at all ages. Little is known of its incidence and long-term prognosis. This study analysed the incidence of lichen planus in women and the mortality of lichen planus patients, based on nationwide Finnish registry data. The incidence was 28 per 100,000 woman-years. The mortality of women with lichen planus was slightly increased because of excesses in mortality from several specific disease categories. These results confirm the importance of long-term and multidisciplinary follow-up of patients with lichen planus.

Table SI
Table SII