Successful Treatment of Nail Lichen Planus by the Janus Kinase 1 Upadacitinib and Literature Review.

Nail lichen planus (NLP) is a chronic inflammatory condition that can lead to considerable cosmetic and functional impairment. Failure to administer prompt and effective treatment may result in the development of permanent scarring and nail loss. The precise pathogenesis of NLP remains poorly understood, and there is currently an absence of safe and effective treatment options. Although not FDA-approved for the treatment of lichen planus, Janus kinase (JAK) inhibitors have shown considerable promise as therapeutic agents for a variety of dermatoses. This case report describes a patient with NLP who showed improvement after six months of treatment with upadacitinib, a selective JAK1 inhibitor. Changes were assessed using the Nail Lichen Planus Severity Index (NALSI) score. Following medication administration, the total score of the NALSI for the patient's nail involvement decreased from 146 to 37. However, a mild recurrence was observed following the reduction of the medication dosage (NALSI score to 47).