Subjects will apply HBP Lotion, 0.05% to all psoriasis plaques identified at Visit 2 twice daily (approximately every 12 hours) for the assigned treatment period or until the investigator verifies the subject's psoriasis has cleared. The study is designed to determine the adrenal suppression potential and pharmacokinetic properties of the test article after the subject applies a maximum of approximately 50 grams per week for up to a two week treatment period. All subjects will have a CST to reassess their HPA axis response at EOS (or earlier if the investigator verifies the subject's psoriasis has cleared). In this study, an abnormal Hypothalamujs Pituitary Adrenal axis response to 0.25 milligram dose of cosyntropin is defined as a post-CST serum total cortisol level of less than equal to18 μg/dL.