Background Case reports have suggested that extracorporeal photochemotherapy (ECP) might be beneficial for the treatment of erosive oral lichen planus (OLP) recalcitrant to conventional immunosuppressive therapies.
Objectives To evaluate over a long-term period the clinical efficacy and toxicity of ECP in a series of patients with refractory OLP, and to monitor peripheral blood lymphocyte subset counts under treatment.
Methods Twelve patients with refractory OLP underwent a standardized protocol of ECP. Sessions were performed twice weekly for 3 weeks, and then the treatment schedule was adapted according to clinical benefit. The disease severity was evaluated monthly on a clinical basis. Complete remission was defined as the absence of any erosion and partial remission as a decrease of at least 50% of erosion surface. Blood cell counts with CD4+ and CD8+ lymphocyte subsets were evaluated every 3 months.
Results All patients showed a decrease of the erosive surface; nine (75%) achieved a complete remission and three (25%) a partial remission. Seven of the eight patients followed for more than 3 years had recurrences of erosions when ECP sessions became less frequent or were stopped. After resumption of an initially accelerated regimen of ECP, all again showed partial or complete remission. Blood lymphocyte counts decreased during treatment, without statistically significant changes in CD4+/CD8+ ratio, and increased during relapse.
Conclusions ECP is an effective alternative therapy in erosive OLP showing resistance to classical treatments. The decrease in blood lymphocyte counts appears to parallel the clinical improvement under treatment.