An investigator-initiated, double-blind, vehicle-controlled pilot study: Assessment for tachyphylaxis to topically occluded halobetasol 0.05% ointment in the treatment of psoriasis

Background: Topical corticosteroids are the most common first-line treatment for psoriasis. Tachyphylaxis, a decreased response to treatment with repetitive application of the drug, is a controversial phenomenon associated with topical corticosteroid treatment. Objective: We sought to prove or disprove tachyphylaxis to occluded halobetasol 0.05% versus vehicle. Methods: Patients with plaque psoriasis were recruited to this study. The study involved 3 phases (1, 2A, and 2B) with each phase being separated by a treatment vacation period. In phases 1 and 2A, 2 plaques were randomized to either halobetasol 0.05% or vehicle ointment application. In phase 2B, halobetasol 0.05% was applied to both. Target Lesion Severity Scale was used for clinical assessment. Results: Twenty patients were enrolled. No difference in time to clearance (P =.88) or time to recurrence (P =.92) of the treated plaques was found between phases 1 and 2A. Percentage of improvement was higher in phase 2A compared with phase 1 (89.4%, P <.05 vs 71%, P <.05), as a result of reduction of vehicle effect. In phase 2B, a greater improvement was found for previously corticosteroid-treated plaques. Limitations: Limitations are small sample size and 1 corticosteroid tested. Conclusion: No evidence of tachyphylaxis to the topical corticosteroid halobetasol 0.05% ointment treatment in patients with plaque psoriasis was found.