Efficacy of Upadacitinib in the Treatment of Acquired Reactive Perforating Collagenosis in a Patient with Type 1 Diabetes: A Case Report and A Literature Review.

Acquired reactive perforating collagenosis (ARPC) is a rare skin condition characterized by collagen loss through the epidermis. We report the first clinical use of the JAK inhibitor upadacitinib for treating ARPC in a 32-year-old woman with a 17-year history of type 1 diabetes, whose persistent pruritic lesions responded poorly to conventional treatments. The patient started a daily regimen of 15 mg upadacitinib and showed a rapid response within 2 weeks, with significant lesion flattening and no new eruptions. By week 4, her pruritus was fully resolved. By week 16, she transitioned to an every-other-day dosing schedule without adverse effects. This article reviews existing literature on JAK inhibitors in ARPC treatment, indicating favorable outcomes. However, given the characteristics of ARPC, sustained maintenance therapy with JAK inhibitors may be necessary. We also explore the potential role of the JAK-STAT signaling pathway in the pathogenesis of ARPC associated with different types of diabetes, suggesting that JAK inhibitors may offer new therapeutic options for diabetic patients with ARPC. The limitations of this article include a small sample size and a lack of cost-effectiveness analysis. Therefore, larger-scale studies are needed to validate the efficacy and safety of JAK inhibitors in the treatment of ARPC and to further investigate clinical differences among patients with various forms of diabetes complicated by ARPC.