Clinical semiotics of immune‑related dermatological adverse events in cancer patients receiving PD‑1/PD‑L1 immune checkpoint inhibitors: data from outpatient oncology practice

Introduction. Malignant neoplasms remain one of the leading causes of mortality worldwide, contributing to the increasing number of patients requiring systemic anticancer therapy. The introduction of immune checkpoint inhibitors (ICIs) has been a breakthrough in oncology, significantly improving survival in several malignancies. However, their use is associated with the development of immune‑related adverse events (irAEs), among which immune‑related dermatologic adverse events (irDAEs) are the most common.
Objective. To research the clinical features of immune-related dermatologic adverse events in patients receiving immunotherapy at Moscow State Budgetary Healthcare Institution «Oncological Center No.1 of Moscow City Hospital named after S.S. Yudin, Moscow Healthcare Department»
Materials and methods. A prospective, single‑center study included 171 patients who received therapy with PD‑1/PD‑L1 inhibitors (pembrolizumab, nivolumab, prolgolimab, atezolizumab, avelumab) during the period 2023–2025 at Oncology Center No. 1, S.S. Yudin City Clinical Hospital, Moscow. The study focused on immune-related dermatologic adverse events (irDAEs) associated with anticancer immunotherapy in oncology patients, with an emphasis on identifying their clinical characteristics. The classification of irDAEs was based on clinical presentation and dermatoscopic findings. Data collection was performed using MS Excel 2019, and statistical analysis was carried out using StatTech v.4.8.11.
Results. The study included 171 patients (57.3% male, mean age 67.2 years). The most common primary malignancies were skin and soft tissue cancers (35.1%) and genitourinary cancers (32.2%). A wide spectrum of immune‑related dermatologic adverse events was identified during therapy. The most frequently observed events were maculopapular rash (31%), isolated pruritus (20.5%), and psoriasiform eruptions (17%). Less commonly, exacerbation of pre‑existing psoriasis (12.9%), lichenoid eruptions (9.9%), vitiligo (4.1%), and bullous pemphigoid (4.1%) were recorded. The rarest manifestations included erythema nodosum (2.3%) and scleroderma‑like reactions (2.3%).
Conclusion. Immune‑related dermatologic adverse events during PD‑1/PD‑L1 inhibitor therapy range from early manifestations, such as maculopapular rash and pruritus, to rare but severe conditions, including bullous pemphigoid and scleroderma‑like reactions. Timely diagnosis and appropriate management are essential to maintain patients’ quality of life and ensure the continuity of anticancer immunotherapy.

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