Polymorphic light eruption (PLE) is a common photodermatosis characterized by the appearance of itching, erythema, papules or vesicles on sun-exposed skin. Though etiology is unclear it is hypothesized that it is an abnormal immune response to autologous antigens generated by ultraviolet radiation (UVR). This randomized, double blinded left-right body side experimental comparison study was designed to assess the preventive effect of a sunscreen and topical DNA repair enzyme-containing after-sun lotion in PLE.