Nickel absorption via skin contact is a major human exposure route, with a large portion of the global population suffering from contact dermatitis and nickel allergy. Among the contact allergens, nickel is reported to be the most reactive in skin and patch tests (Lu et al., 2009). Whereas nickel contact dermatitis was previously reported to occur in up to 10% of women
but only 1% of males (WHO, 1991),