Association of A, B, O and Rh blood groups with Vitiligo

Vitiligo is an acquired depigmentary dermatitis on an otherwise normal skin, which involves 1-2% of general population. Despite Various hypotheses and theories postulated, its etiology remains unknown. Genetic factors and blood groups seem to be implicated, to some extent, in the etiology of the disorder. This study was done to determine the association of Vitiligo with A, B, O blood groups and Rh. In this case control study two groups were compared one with 100 Vitiligo cases and the other (the control group) consisting of 100 patients without the disorder in the dermatology clinics of Birjand. Then, blood groups and Rh of both groups were determined. Incidence of each blood group among patients was compared with that of the control group. Data were analyzed by SPSS package, using t and chi- square tests. Blood groups A, B, AB, and O in Vitiligo cases were found to be, 32%, 33%, 7% and 28% while they were 43%, 21%, 13%, and 23% in the controls, respectively. Thus, the differences were significant (2=6.85, P<0.05). The incidence of Rh positive and Rh negative blood groups in Vitiligo cases were found to be 87% and 13% compared to 83% and 17% in the controls respectively, but these differences werent significant (2=6.7, P>0.05). The results obtained through this study show that subjects with blood group B are more susceptible to Vitiligo as compared to those with other groups but there is no significant association of Vitiligo with Rh.