Treatment of oral erosive lichen planus with 1% pimecrolimus cream - A double-blind, randomized, prospective trial with measurement of pimecrolimus levels in the blood

Objectives: To evaluate the efficacy of 1% pimecrolimus cream in treating oral erosive lichen planus and to assess its tolerance. Design: Double-blind randomized trial with placebo control. Setting: Outpatients of the Department of Dermatology, University Hospital of Nice, from December 21, 2004, to April 19, 2005. Patients: Fourteen consecutive patients with oral erosive lichen planus confirmed by histological examination and with a clinical score superior to 3. Of the 14 patients, 2 did not meet the inclusion criteria and 12 were enrolled in the trial. Intervention: The intervention was 1% pimecrolimus cream or its vehicle, which was applied on ulcerated lesions twice a day for 4 weeks. Main Outcome Measures: The efficacy of the treatment was quantified using a 12-point clinical score. The blood level of pimecrolimus was analyzed on days 0 (baseline), 14, and 28. Results: in the placebo group, the mean score was 4.67 on day 0 vs 3.33 on day 28 (P=.22). In the pimecrolimus group, the mean score was 6.83 on day 0 vs 3.33 on day 28 (P=.04). In the pimecrolimus group, blood concentrations of pimecrolimus were always above the threshold (mean value, 2.84 ng/mL; extreme values, 0-6.19 ng/mL). Pimecrolimus cream was well tolerated, and only transient burning sensations were reported by some subjects. Each of the patients in the pimecrolimus group whose condition improved subsequently relapsed when assessed 1 month after treatment. Conclusions: The 1% pimecrolimus cream seems to be an effective and well-tolerated treatment for oral erosive lichen planus. The finding of systemic levels of pimecrolimus after mucosal applications necessitates long-term study because it seems that long-term application is required to maintain clinical improvement.