Oral Lichen Planus or Oral Lichenoid Reaction? A Literature Review

Abstract

Background and Aim: Oral lichen planus (OLP) is a chronic, inflammatory, T-cellmediated autoimmune oral mucosal disease. Oral lichenoid lesions develop as a type IV hypersensitivity reaction. Both of these entities are potential precancerous conditions; this adds to their clinical significance. The purpose of this literature review was to detect the similarities and the differences of these lesions to enhance the information of colleagues in managing these groups of patients. Materials and Methods: For this review, we searched Cochrane, Medline, and Embase databases from January 1990 to the end of October 2018. A total of 96 published papers, including review papers, case reports, cohort studies, case-control studies, and meta-analysis studies, were included and analyzed. Results: OLP and oral lichenoid reactions are two distinct diseases. They can be clinically similar but they have different etiologic factors. A histopathological study is necessary to differentiate them. Conclusion: The definitive diagnosis of these conditions is extremely important given their potentially premalignant nature. A timely diagnosis probably results in proper management. Based on the present research, the final differentiation between OLP and oral Lichenoid reactions relies on both clinical and histopathological manifestations according to the modified World Health Organization (WHO) criteria.

Serum and salivary levels of lactate dehydrogenase in oral squamous cell carcinoma, oral lichen planus and oral lichenoid reaction

“…However, histopathological differences between OLP and OLRs, including infiltration of different inflammatory cells, more perivascular inflammation, higher mitotic index and basement membrane cleft in OLRs than OLP [ 41 ] and more Civatte bodies due to cell membrane degeneration [ 12 ] can justify the higher levels of LDH in OLRs than OLP. According to the literature, the prevalence of malignant transformation is 0.1–5.3% in OLP and 0.5–6.5% in OLRs [ 20 ]. According to a new classification by Sarode et al OLRs are premalignant lesions under group 2b, which is a carcinogenic group due to chronic mucosal inflammation as the result of external stimuli [ 42 ].…”

“…The process of malignant transformation of OLRs is related to field cancerization. In this process, all related events in such patients expose them to higher risk of primary malignancy [ 20 ].…”

“…Since different clinical types of OLP have different risks of malignant transformation, difference in distribution of OLP types in the study by Rai et al can explain the variability in the reported results. The suggested hypotheses for OLP malignancy include increased levels of inflammatory cytokines and growth factors and oxidative destruction of DNA due to chronic inflammation, presence of Candida albicans in OLP, use of immunosuppressive or immunoregulatory agents, and increased lipid peroxidation [ 20 ].…”

“…Sufficient data regarding the risk of malignant transformation of different types of OLRs are not available, but it appears that different types of graft versus host disease and oral lichenoid contact lesions have higher risk of malignant transformation than drug-induced OLRs [ 18 , 19 ]. The risk of cancer development at the site of chronic inflammation, and presence of inflammatory cells in the cancer tissue suggest the correlation of chronic inflammation and malignant transformation of lesions into oral cancer [ 20 ].…”

“…However, the level of LDH in OLRs has not been studied. Evidence shows that OLRs have higher rate of malignancy than OLP [ 20 ]. Many studies have measured the serum or tissue level of LDH isoenzymes in oral lesions [ 2 , 3 , 28 , 29 , 31 ].…”