Successful treatment of erosive lichen planus with Upadacitinib complicated by oral squamous cell carcinoma.

Erosive lichen planus is a chronic auto-inflammatory disease which affects the stratified squamous epithelia resulting in painful ulcerations of both the skin and mucosal surfaces, and has a known malignant potential. Management of erosive lichen planus has proven to be difficult; however, recent reports of treatment with Janus kinase inhibitors such as Upadacitinib, are encouraging. This report outlines the third reported case of erosive lichen planus to be successfully treated with Upadacitinib in a 70-year-old woman with treatment-resistant disease. In addition, we report the complication of oral squamous cell carcinoma which became apparent once the extensive erosive lichen planus had healed. This case report highlights the importance of monitoring for mucosal squamous cell carcinoma in areas affected by erosive lichen planus, as squamous cell carcinoma can mimic the erosions of erosive lichen planus.