Role of HHV-7 and Epstein-Barr virus in the pathogenesis of oral lichen planus: a systemic review

Herpes group viruses infect almost 90% of the population, mostly in childhood. In a large number of cases, the viruses are not fully eliminated after the primary infection and remain in the form of persistent infection throughout life. Oral lichen planus (OLP) is the most common non-infectious, chronic inflammatory oral disease affecting 1-2% of the general adult population. Its etiology is unknown, however there is some information on the involvement of Epstein-Barr virus (EBV) in the etiology of OLP and almost none on the role of human herpes virus-7 (HHV-7). The aim of the study was to provide currently available information on the association of EBV and HHV-7 with the development of oral lichen planus.hjkk Online databases (PubMed, Scopus, Research gate, Science direct and Google Scholar) were searched from date of inception till November 2020. Studies were included if they met the following criteria: 1) observational studies that assessed the relationship between HHV-7 and EBV with OLP, 2) the study comprised OLP patients and control subjects, 3) diagnosis of OLP was confirmed histologically , and 4) articles were in English. A total of 10 studies (from 27) comprising 403 OLP cases and 216 controls were included. The results of the pooled studies revealed a significant positive association between EBV and OLP in 5 studies prevalence being 25.5 % and just one study suggested that there is 33.3% association between HHV-7 and OLP. Thus, the results suggest a significant positive association between presence of viruses EBV and HHV-7 and development of oral lichen planus. The results of the present systematic review suggest that EBV and HHV-7 infection is significantly associated with increased risk of OLP. However, these results are preliminary, and high‐quality, large‐scale studies are required to further explore the potential role of HHV-7 and EBV in the pathogenesis of OLP.