Topical sirolimus: a novel treatment for chronic erosive plantar lichen planus

We describe the successful treatment of recalcitrant plantar erosive lichen planus (LP) with topical sirolimus (Rapamycin), a macrolide related immunosuppressant. A 79 year old man presented with a 3 year history of an itchy, uncomfortable hyperkeratosis on the soles of both feet thought to be eczema. Ultrapotent topical corticosteroids and keratolytics had little impact. Topical phototherapy led to painful ulceration of the left sole. The diagnosis was reconsidered with histology confirming changes of erosive lichen planus. Ulceration persisted despite daily ultrapotent topical corticosteroid and topical tacrolimus. Oral prednisolone (20 mg/ day) provided short-term relief. Azathioprine and ciclosporin were abandoned due to inefficacy and adverse effects. After 3 years of refractory disease, oral sirolimus solution (1mg/ ml) was applied as a daily wet dressing. Pain was reduced after 4 weeks and ulcers healed completely after 20 weeks. This case report highlights the challenges encountered in the management of erosive plantar LP and the efficacy of sirolimus as a potential therapeutic agent.