This will be an open label, bilaterally-controlled single center study. Thirty subjects with plaque type psoriasis will be enrolled in the study. All subjects will receive treatment on two target lesions that are similar in erythema, scaling and induration, and symmetric in anatomic location. The severity of their target lesions will be assessed using a modified Psoriasis Area and Severity Index (PASI) scoring system (Appendix A). Symmetrical target lesions must each be rated at a PASI score equal to or greater than 7 and be within 1 PASI score of each other.