Hepatitis C virus and lichen planus: A review

The relationship between hepatitis C virus (HCV) infection and oral lichen planus (OLP) remains a matter of controversy. It is important to determine whether there is an association between OLP and HCV infection so that guidelines regarding the routine HCV testing of patients with OLP can be developed for clinicians. The objective of this article was to review and summarize the published literature on the association between OLP and HCV and to describe future directions. A search of the computerized database MEDLINE (1966–June 2003) was conducted. The bibliographies of articles identified by means of MEDLINE were also searched. Any studies reporting the prevalence of HCV in a group of patients with LP either with or without a control group were included in this review. Also included were studies comparing the clinical and histologic features of LP among patients with and without HCV infection, studies on the presence of HCV within LP lesions, and studies of HCV genotypes among patients with LP. Thirty-two studies conducted in various parts of the world were identified. Study types included prevalence studies on HCV exposure among patients with OLP (0%-62%), prevalence of OLP among patients with HCV infection (1.6%-20%), and case-control studies of this association. In addition, the results from 3 studies on the replication of HCV in the oral mucosa, 3 studies on the genotype of HCV in OLP patients, and 4 studies comparing the clinical and histologic features of OLP in HCV-infected and uninfected individuals have been summarized. At present, studies on the association of OLP and HCV provide enough information to raise a number of interesting questions about this association. Important biases—including selection bias; investigator bias due to lack of blinding and the possible resultant nondifferential misclassification of disease; and possible confounding by age in the studies published—make it difficult to draw firm conclusions. However, the need for future studies that take into consideration all these factors in the study methodology is highlighted by this review.