Relationship between Personal Temperaments Based on the Traditional Medicine Knowledge and Lichen Planus and Lichenoid Reaction Disorders

Oral lichen planus and lichenoid reactions are autoimmune chronic inflammatory diseases. Since the inflammatory system is the main pathological process in these lesions, some etiological roles for inflammatory cytokines and personal temperaments (Mizaj) are proposed. In this preliminary study, establishing such an association between personal temperaments with oral lichen planus and lichenoid reactions would develop new horizons for better preventive programming to prevent or control the disease course in affected patients. This case-control study was carried out among  384 patients referred to the oral medicine department of dental school, Tehran University of Medical Sciences, from 2000 to 2017. They were categorized into three groups as follows: oral lichen planus (128),  oral lichenoid reactions (128), and healthy control group (128). The temperament was assessed by Mojahedi et al. validated questionnaire, and the results were compared across the groups. Warm temperament was significantly higher in the lichen planus group (P=0.0001). The dry temperament was higher in oral lichen planus and lichenoid groups. In these groups, the intermediate group had the least rate, but in the control group, the moist temperament was less common. No statistically significant difference existed between groups in this era (P=0.210). However, among mixed temperaments, the warm and moist temperament was the same across the groups (P=0.195); the warm and dry temperament was significantly more common in cases with oral lichen planus (P < 0.001); and the cold and dry temperament (P=0.017) and cold and moist temperament (P <0.001) were significantly more common in the control group. The only difference between the two groups of control and lichenoid reactions was cold and dry temperament (P=0.008). This study revealed that warm temperament is related to oral lichen planus. Reestablishing this matter in future studies would help develop some evidence-based preventive strategies to reduce the burden of oral lichen planus.