Affiliation:
1. Department of Dermatology and Psoriasis Treatment Center, University of California-San Francisco, San Francisco, California
2. Kaiser Permanente, Department of Dermtology, Los Angeles Medical Center, Los Angeles, California
Abstract
Objective The aim of this study was to compare the efficacy of halobetasol propionate 0.05% ointment administered once daily with that of the ointment administered twice daily in combination with 12% ammonium lactate lotion for treatment of plaque psoriasis. A second objective was to investigate the benefits of maintenance therapy with ammonium lactate 12% lotion. Design The study was a randomized, investigator-masked, parallel trial. In the first phase, subjects applied halobetasol 0.05% ointment either once or twice daily in combination with 12% ammonium lactate lotion twice daily for 2 weeks. In the second phase, subjects either continued ammonium lactate twice daily or discontinued all treatment for 4 weeks. Setting University of California San Francisco Psoriasis and Skin Treatment Center. Participants: The study comprised 40 patients with a target plaque of at least 1 cm2 and a Psoriasis Severity Assessment (PSA) score of at least 6. Measurements Plaque induration, scale, and erythema were recorded at weeks 0, 1, 2, 4, and 6. Paired t-tests compared improvement between the two groups; unpaired t-tests compared differences between the two arms. Results No significant difference was noted in efficacy between once- and twice-daily halobetasol application at weeks 0 and 2 for induration (respectively, P = 0.10 and P = 0.21), scale (P = 0.49 and 0.51), erythema (P = 0.42 and 0.14), and total PSA (P = 0.37 and 0.23). A significant difference was found in scale between weeks 2 and 4 (P = 0.04) and weeks 2 and 6 (P = 0.03) in favor of patients continuing ammonium lactate lotion. Conclusion Once-daily halobetasol ointment achieves results similar to those of twice-daily application when used with ammonium lactate lotion in plaque psoriasis treatment. Sequential therapy with 2-week halobetasol ointment followed by twice-daily ammonium lactate may enhance therapeutic duration.