Hepatitis C virus infection and lichen planus: a systematic review with meta-analysis

Hepatitis C virus (HCV) is one of the major causes of chronic liver disease worldwide but its morbidity is also due to a variety of extra-hepatic manifestations including mixed cryoglubulinemia, non-Hodgkin lymphoma, diabetes, porphyria cutanea tarda and lichen planus. The aims of this study were to conduct a systematic review and a meta-analysis on the prevalence of HCV in lichen planus patients and on the prevalence of lichen planus in chronic HCV infection.Bibliographic searches were conducted in several electronic databases. Pooled data were analysed by calculating odds ratios, using a random effects model.Thirty-three studies comparing the seroprevalence of HCV in lichen planus patients and six reporting the prevalence of lichen planus in patients with HCV infection were included in the meta-analysis. The summary estimate showed that LP patients have significantly higher risk (odds ratio 4.85; 95% confidence interval 3.58-6.56) than controls of being HCV seropositive. A similar odds ratio of having lichen planus was found among HCV patients (4.47; 95% confidence interval 1.84-10.86). Sub-analyses indicated that variability of HCV/lichen planus association seemed only partially depending on geographic effect.