Extracorporeal Photopheresis (ECP) for Refractory Lichenoid Disorders: A Retrospective Analysis of Efficacy and...

Erosive Lichen Planus (ELP) is a debilitating T-cell mediated dermatosis often refractory to conventional therapies. While Extracorporeal Photopheresis (ECP) is established for other T-cell diseases, long-term data on its efficacy across the lichenoid spectrum, including non-erosive forms, remain limited. We conducted a retrospective study at Amiens-Picardie University Hospital including five adult patients with refractory lichen (erosive or non-erosive) treated with ECP after January 2021. Clinical response was assessed every 3 months, and progression-free survival (PFS) was analyzed. Five female patients were included: 3 with ELP and 2 with lichen sclerosus (LS) variants. All patients achieved an initial clinical response (1 complete, 4 partial). The median time to best response was 7.5 months (95% CI: 0.8-13). At 3 months, 40% were on ECP monotherapy. Over a median follow-up of 47 months, only one patient progressed. At the last follow-up, two patients remained on ECP with sustained clinical benefit. Our results confirm the excellent long-term efficacy and safety of ECP in refractory ELP. While significant initial benefits were observed in non-erosive scleroatrophic lichen, the durability of response warrants further investigation. ECP is an effective, well-tolerated, and sustained therapeutic option for refractory ELP and holds promise for non-erosive lichenoid pathologies. Larger prospective studies are needed to clarify its role as monotherapy versus combination therapy.