Acquired Reactive Perforating Collagenosis Treatment with Upadacitinib: A Case Report

Background: Reactive perforating collagenosis (RPC) is a rare and chronic perforating skin disease characterized by epidermal elimination of collagen through the skin. Lesions are believed to develop at sites of trauma and are exacerbated by scratching. There are few reported cases of treatment options for patients with severe, resistant RPC. Case Presentation: We present the case of a previously asymptomatic female in her 60s with a history of chronic kidney disease on dialysis presented to clinic with a chief complaint of worsening, pruritic skin lesions. The patient was treated with upadacitinib and after five days her pruritus, perforating nodules, and papules significantly improved. On follow-up approximately two weeks later, the patient noted her pruritus has significantly improved. Discussion: Upadacitinib selectively inhibits JAK-1 and targets multiple proinflammatory cytokines including IL-4, IL-13, IL-22, IL-31, and IFN-γ which may contribute to the pathogenesis of RPC. This case reports highlights the utility of upadacitinib as a well-tolerated treatment option for patients with RPC that not only manages symptoms, but progression of lesions. Conclusion: Upadacitinib is a well-tolerated, useful treatment option for patients with difficult-to-treat RPC that manages symptoms and progression of lesions. Future research should be dedicated to confirming the effectiveness within a larger patient population.