Subjects will be restricted from using systemic therapies for psoriasis during this study, including Psoralen Ultraviolet A (PUVA) photochemotherapy and herbal therapies. All topical medications, except the study medications, and UVB phototherapy are prohibited on the target lesions. All of the other psoriasis lesions on the body can be treated as usual with other topical medications and Ultraviolet B (UVB) phototherapy as long as it does not impact on the two target lesions.