5PSQ-139 Dupilumab-associated scarring alopecia in a patient with atopic dermatitis: a case report

<h3>Background and Importance</h3> Atopic dermatitis is a multifactorial systemic condition characterised by immune dysregulation and impaired skin barrier function. Its prevalence ranges from 5–20% in the general population, with higher rates (around 20%) in children and adolescents. Dupilumab, a targeted biological therapy, has significantly improved moderate to severe atopic dermatitis management, offering relief in cases resistant to conventional treatments. <h3>Aim and Objectives</h3> To report a case of an unreported adverse effect (AE) linked to dupilumab in a patient with severe atopic dermatitis. <h3>Material and Methods</h3> We present a case of scarring alopecia due to dupilumab in a patient with severe atopic dermatitis. A 16-year-old asthmatic patient with food allergies, diagnosed with atopic dermatitis and treated with topical corticosteroids since childhood. In January 2023, he started oral cyclosporine; however, after 11 months of treatment with increasing doses, the patient still exhibited generalised erythema, affecting sleep, with skin lichenification and scaling. (EASI score of 28). In December 2023, dupilumab 600 mg was initiated, followed by 300 mg every two weeks. After 3 months (March 2024), with a moderate treatment response, the patient reported significant hair loss. Dermatology consultation revealed erythematous lesions on the scalp, suggesting scarring alopecia, that was later confirmed by pathology. Suspecting an AE, dupilumab was discontinued, and switching to upadacitinib was considered. Epidemiological and clinical data were obtained from the digital medical record and outpatient management system. <h3>Results</h3> Two weeks after discontinuation, the patient reported improvement in skin and scalp conditions. The AE was reported to the Spanish Pharmacovigilance System through its Electronic Yellow Card System . The Naranjo algorithm was used to assess the causal link between dupilumab and the AE, which was deemed probable (score 6). <h3>Conclusion and Relevance</h3> Reporting suspected EAs is essential for post-marketing safety. It allows identification of new adverse effects. This case of dupilumab-induced scarring alopecia emphasises the importance of ongoing pharmacovigilance, even for well-established treatments. It also highlights the role of healthcare professionals, especially pharmacists, in identifying rare or unexpected EAs early in treatment, contributing to better patient management. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest