INTRODUCTION: Cast immobilisation remains the mainstay of treatment for various fractures in paediatric patients, yet patients commonly complain of skin irritation and discomfort. This study aimed to perform a qualitative and quantitative evaluation of the effects of cast immobilisation on the skin of children and adolescents. MATERIALS AND METHODS: Patients aged 6-17 years of age with a fracture treated in a fiberglass short-arm or short-leg cast were recruited. Transepidermal water loss (TEWL), stratum corneum (SC) hydration, hair density and presence of any skin signs were assessed before and after cast. Patients were required to complete a weekly questionnaire to rate itch, malodour, warmth, and dampness of the skin under the cast. RESULTS: A total of 60 subjects completed the study. Thirty-six patients received a short-arm cast; 24 received a short-leg cast. Upon cast removal, TEWL was significantly increased on the volar surface of the arms and legs ( <0.05), and the dorsal surface of the arm ( <0.05). Likewise, SC hydration was significantly increased at most sites ( <0.05), except the volar surface of the leg ( = 0.513). There was no change in hair density. Throughout the duration of casting, there was an increase in itch and malodour scores. CONCLUSION Moderate but significant changes in TEWL, SC hydration and subjective symptoms were observed during the duration of cast immobilisation, demonstrating that cast immobilisation for up to 4 weeks exerts moderate adverse impact on patients' skin. Further studies to explore the use of better materials for cast immobilisation to improve skin barrier function and overall patient satisfaction are warranted.