• Background and Design.—
To avoid systemic side effects, topical and intralesional administration of cyclosporine has been used; however, only intralesional administration has been successful. To understand more about the dosing requirements and resultant tissue levels of intralesional cyclosporine, we injected psoriasis plaques in a double-blind fashion with three different concentrations of cyclosporine (17 mg/mL in seven patients, 10 mg/mL in 13 patients, and 2.5 mg/mL in 11 patients) or matching vehicle three times weekly for 4 weeks.
Results.—
Statistically significant improvement was observed in plaques treated with 17 mg/mL (P =.003) compared with vehicle-treated plaques; the improvements in plaques treated with 10 mg/mL (P=.078) and 2.5 mg/mL (P=.054) achieved marginal statistical significance compared with vehicle treatment. Four weeks after discontinuation of ther