Real-World Effectiveness of Secukinumab in Congenital Ichthyoses: A Retrospective Monocentric Case Series

Background/Objectives: Congenital ichthyoses (CI) are inherited disorders of keratinization characterized by epidermal barrier dysfunction, abnormal desquamation, and variable degrees of inflammation. Increasing evidence suggests a role for IL-23/Th17-mediated immune dysregulation in some CI subtypes, providing a rationale for targeted biologic therapies. Secukinumab, an anti-IL-17A monoclonal antibody, has emerged as a potential therapeutic option, although real-world evidence remains limited. This study evaluated the effectiveness of secukinumab in adult patients with severe CI. Methods: We performed a retrospective monocentric case series including eight adult patients with severe congenital ichthyosis treated with secukinumab for at least six months and followed for up to 56 months. Clinical outcomes included Investigator Global Assessment (IGA) scores for erythema, scaling, scalp involvement, and palmoplantar hyperkeratosis, together with pruritus assessed by Numeric Rating Scale (NRS). Results: Erythema and scaling showed most of their improvement during the first six months of treatment, after which mean clinical scores remained relatively stable throughout follow-up. At the last available assessment, improvement rates were 100% for erythema, 87.5% for trunk and limb scaling, 100% for scalp scaling, and 75% for palmoplantar hyperkeratosis. Hyperkeratosis showed a less pronounced response than inflammatory manifestations. Pruritus improved within the first 3–4 months of treatment and was sustained over time, with mean NRS scores decreasing from 6.5 at baseline to below 4 within 3–4 months. No discontinuations due to adverse events or lack of efficacy were recorded. Conclusions: Secukinumab was associated with clinically meaningful improvements in inflammatory manifestations of CI, particularly erythema and pruritus, while showing a more limited effect on hyperkeratotic features. These findings support the potential role of IL-17 inhibition in selected CI phenotypes.