A Case of Pityriasis Lichenoides Chronica Successfully Treated With Upadacitinib.

Pityriasis lichenoides chronica (PLC) is a chronic cutaneous disorder of unknown cause that is thought to be a proliferation of T-cells in response to an antigen or infection. We introduce a case of a 62-year-old female who presented with an erythematous nonpainful eruption of well-demarcated annular and polycyclic papules and plaques with fine whitish peripheral scale distributed on the back, shoulders, chest, arms, and legs. Skin biopsy was consistent with PLC. After minimal improvement with systemic and topical corticosteroids, oral upadacitinib 15 mg once daily was started. Following 1 month of treatment with oral upadacitinib, the complete remission of PLC was observed. Thus, upadacitinib as a Janus kinase (JAK) inhibitor may be a novel treatment for PLC. However, more studies are needed to explore the efficacy and safety of JAK inhibitors for lichenoid disorders, such as PLC and others.