title: Etiogenic study on oral lichenoid reactions among Tamil Nadu population: a prospective cohort study.
abstract: BACKGROUND
  Most of the clinical, epidemiological, and etiogenic studies on oral lichenoid reactions (OLRs) have been undertaken in the United States, UK, Scandinavia, and other European countries. So far, very few cohort studies on a small population have been documented from South Asian region to implicate the role of various causative agents in the precipitation of OLR.
  
  
  OBJECTIVE
  To implicate the role of various allopathic, alternate medicinal drugs, dental materials, etc., in the precipitation OLRs; to evaluate the pattern of remission; and to estimate the time period for the remission of lesions following the discontinuance of the suspected agents in the population of Tamil Nadu.
  
  
  METHODS
  A total of 102 patients were included, of whom 51 (mean age 43.3 years, SD 14.59) formed the study group, who possessed a positive drug history to the intake of either potential allopathic or alternate drugs or had recent dental metallic fillings/restorations, and 51 were (mean age 47.86 years, SD14.67) in the control group possessing oral lichen planus (OLP). The patients were followed up at a monthly interval period for a period of 18 months.
  
  
  RESULTS
  Complete remission of signs and symptoms was noticed in 41 patients, partial remission in 6, no change in 2, newer lesions in 1, and flaredup lesions were observed in 1 participant in the study group. The mean onset time for lichenoid eruptions was found to be 2.5 months (SD 58.82) and the mean remission time after discontinuing the drug was 9.1 months (SD 4.7).
  
  
  CONCLUSIONS
  OLR could be implicated to documented lichenoid agents like calcium channel blockers, ACE inhibitors, atarvastatin, metformin, glibenclamide, dapsone, carbimazole, silver amalgam fillings, etc.in southSouth Indian population. Furthermore, the drugs like oflaxacin, arsenical album, and yellow orpimentumwere also found to have strong implication in the precipitation of OLR. Discontinuance of the suspected agents resulted in healing in the majority of cases.
authors.affiliation: Dental Surgeon, Raj Dental Clinic, Madurai, Tamilnadu, India.
authors.forename: Eswar
authors.initials: E
authors.lastname: Nagaraj
authors.forename: Priya
authors.initials: P
authors.lastname: Eswar
authors.forename: Roopam Pal
authors.initials: RP
authors.lastname: Kaur
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007194:India; D017676:Lichen Planus, Oral / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors