免疫检查点抑制剂 (ICIs) 彻底改变了癌症治疗，但它们也可能诱发免疫相关不良事件 (irAE)，包括苔藓样皮疹等皮肤毒性。 Pembrolizumab 是一种 PD-1 抑制剂，因其与扁平苔藓样反应相关而闻名，而免疫疗法与 MK-4830（一种针对 ILT-4 的新型全人 IgG4 单克隆抗体）相结合的副作用仍然有限。我们介绍了一名患有转移性乳腺癌的 47 岁女性病例，她在使用 MK-4830 和派姆单抗 9 个月后出现了 2 级不良事件通用术语标准 (CTCAE) 苔藓样反应。带有威克姆皮纹的融合性红斑丘疹主要出现在四肢。高效外用皮质类固醇的初始治疗被证明是不够的，但每日泼尼松 40 mg 可使扁平苔藓样反应得到令人满意的缓解，允许继续进行免疫治疗而无需调整剂量。该病例强调了由 MK-4830 和 MK-4830 诱导的苔藓样皮疹的新发生派姆单抗在乳腺癌治疗中的应用。该患者成功接受了口服泼尼松治疗，在不中断 ICI 治疗的情况下控制了皮肤症状。我们强调，早期诊断和治疗低度苔藓样疹可以预防 ICI 的停止，从而结合管理 irAE 和避免癌症进展的益处，从而实现更好的长期预后。版权所有 © 2024 Kachlik、Błażewicz、Ciarka 和诺维茨基。

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, yet they can induce immune-related adverse events (irAEs), including cutaneous toxicities such as lichenoid eruptions. Pembrolizumab, a PD-1 inhibitor, is known for its association with lichen-planus-like reactions, while the side effect profile of combining immunotherapy with MK-4830, a novel fully human IgG4 monoclonal antibody that targets ILT-4, remains limited.We present a case of a 47-year-old female with metastatic breast cancer who developed a grade 2 Common Terminology Criteria for Adverse Events (CTCAE) lichenoid reaction after 9 months of MK-4830 and pembrolizumab use. Confluent, erythematous papules with Wickham's striae appeared predominantly on the extremities. Initial therapy with high-potency topical corticosteroids proved insufficient, however prednisone 40 mg daily resulted in satisfactory remission of lichen-planus-like reaction, permitting continued immunotherapy without dosage adjustment.This case highlights the novel occurrence of lichenoid eruption induced by MK-4830 and pembrolizumab in breast cancer treatment. The patient was successfully treated with oral prednisone, which controlled the skin symptoms without interrupting ICI therapy. We emphasize that early diagnosis and treatment of low-grade lichenoid eruption can prevent the cessation of ICIs, thereby combining the benefits of managing irAEs and avoiding cancer progression, leading to a better long-term prognosis.Copyright © 2024 Kachlik, Błażewicz, Ciarka and Nowicki.