evaluation of the association between abo blood groups and lichen planus

Background and objectives: lichen planus (lp) is a skin disease with unknown origin; however, some studies revealed that abo blood group is correlated with lp; the current study aimed at evaluating this possible relationship. methods: the current case-control study was conducted on 79 patients with lp referring to shohada-e-tajrish and loghman-e-hakim hospitals as well as 79 healthy donors as the control group. results: the most common type of lp was cutaneous phenotype (57 out of 79); in the patients group, the frequency of abo blood groups was a (38%), o (36.7%), b (16.5%) and ab (8.9%), while it was o (34.2%), a (27.8%), b (26.6%), and ab (11.4%) in the control group. blood group a observed more frequently in patients with mucosal phenotype (p = 0.012), but the correlation between lp and rh was not significant (p = 0.3). conclusions: the results of the current study revealed that rh has no impacts on lp. based on the current study findings, individuals with blood group a were more susceptible to mucosal phenotype of lp.