Radiation-Induced Skin Injury: Mechanisms, Clinical Manifestations, and Management.

Radiation-induced skin injury (RISI) is among the most common complications of cancer radiotherapy, affecting up to 95% of patients. These injuries include acute and chronic reactions that impair quality of life, necessitate treatment modifications, and contribute to long-term morbidity. This review synthesizes current understanding of the pathophysiology, clinical manifestations, histopathologic features, and management strategies for RISI, with emphasis on approaches most relevant to dermatologists and oncology clinicians. Acute radiation dermatitis (ARD) develops in 85%-95% of patients receiving radiotherapy, driven by DNA damage, reactive oxygen species, and pro-inflammatory cytokines. Clinical severity ranges from faint erythema to moist desquamation and ulceration, with severe reactions in up to 20%. Chronic radiation dermatitis (CRD) affects 5%-15% of survivors and results from sustained fibroblast activation and microvascular injury, leading to fibrosis, pigmentary changes, atrophy, and a two- to threefold increased risk of secondary skin cancer. Histopathology varies from basal keratinocyte apoptosis and epidermal thinning in ARD to dermal sclerosis, adnexal loss, and vascular ectasia in CRD. Preventive measures such as gentle cleansing, moisturization, and prophylactic corticosteroids reduce ARD severity by 15%-30%. For established disease, antimicrobial dressings shorten ulcer healing by 20%-40%, while long-term therapies including pentoxifylline-tocopherol, vascular lasers, and autologous fat grafting improve tissue pliability, pigmentation, and function. Dermatologists are uniquely positioned to lead prevention, diagnosis, and management of RISI. A proactive, multidisciplinary approach anchored by dermatologic expertise and evidence-based strategies is essential to reducing morbidity, enhancing healing, and improving quality of life. Given the worldwide use of radiotherapy, these approaches are intended to be adaptable across diverse healthcare systems, supporting dermatologists globally in patient care.