Background: Acquired reactive perforating collagenosis (ARPC) is a rare perforating dermatosis characterized by transepidermal elimination of degenerated collagen fibers. It frequently develops secondary to systemic comorbidities, including diabetes mellitus, chronic kidney disease (CKD), and atopic dermatitis (AD), which limit therapeutic options and contribute to unpredictable outcomes.

背景：获得性反应性穿孔性胶原病（ARPC）是一种罕见的穿孔性皮肤病，其特征为变性胶原纤维的跨表皮排出。该病常继发于多种系统性合并症，包括糖尿病、慢性肾脏病（CKD）和特应性皮炎（AD），这些合并症限制了治疗选择并导致预后难以预测。

Here, we report a case of ARPC with concurrent AD in a patient with type 2 diabetes mellitus and stage 4 CKD, who experienced acute paradoxical exacerbation within 24 h of dupilumab initiation and achieved sustained remission with upadacitinib..

在此，我们报告一例合并特应性皮炎的急性红斑性脓疱病病例，患者患有2型糖尿病和4期慢性肾脏病，在启动度普利尤单抗治疗24小时内出现急性反常性加重，随后通过乌帕替尼治疗获得持续缓解。

Case summary: A 72-year-old male presented with a 5-year history of recurrent generalized pruritus, erythema, papules, and nodules. Despite treatment with glucocorticoids and anti-allergic medications, the skin lesions remained poorly controlled. Histopathological examination revealed transepidermal elimination of collagen fibers through the ulcer bed into the underlying dermis.

病例摘要：一名72岁男性患者，有5年复发性全身性瘙痒、红斑、丘疹和结节病史。尽管接受了糖皮质激素和抗过敏药物治疗，皮损仍控制不佳。组织病理学检查显示胶原纤维经溃疡床穿表皮排出至下方真皮层。

Verhoeff-van Gieson staining demonstrated collagen fibers traversing the ulceration. The patient was diagnosed with ARPC. He had poorly controlled comorbidities, including AD, type 2 diabetes mellitus, and stage 4 CKD. Dupilumab was administered as a single 600 mg dose but was discontinued due to paradoxical worsening within 24 h.

Verhoeff-van Gieson染色显示胶原纤维穿过溃疡区域。患者被诊断为ARPC。其合并症控制不佳，包括特应性皮炎（AD）、2型糖尿病和4期慢性肾脏病（CKD）。给予单次600 mg剂量的度普利尤单抗，但因在24小时内出现反常性恶化而停药。

Following two years of recurrent relapses despite systemic corticosteroids, antihistamines, and thalidomide, oral upadacitinib 15 mg once daily was initiated, with marked resolution of skin lesions and pruritus. After 9 months of treatment, upadacitinib was discontinued, and the patient remained in stable remission at 1-year follow-up.

在尽管接受系统性皮质类固醇、抗组胺药和沙利度胺治疗，但仍反复发作两年后，开始每日一次口服15 mg乌帕替尼，皮肤损害和瘙痒显著消退。治疗9个月后停用乌帕替尼，患者在1年随访时仍保持稳定缓解。

No adverse effects were observed, and renal function remained stable throughout treatment..

未观察到不良反应，治疗期间肾功能保持稳定。

Conclusion: This case suggests that upadacitinib is a promising salvage therapy for refractory ARPC, particularly after failure of Th2-targeted biologics. Its favorable safety profile at the standard dose without adjustment in stage 4 CKD supports its use in patients with complex comorbidities.

结论：本病例提示，乌帕替尼是治疗难治性特应性红斑皮病（ARPC）的一种有前景的挽救性疗法，尤其在靶向Th2的生物制剂治疗失败后。其在标准剂量下良好的安全性谱，且在4期慢性肾脏病（CKD）患者中无需调整剂量，支持其在合并复杂共病患者的应用。