Navarini, Alexander

Abstract Darier disease (DD) is a rare autosomal dominant genodermatosis. This comprehensive review, developed by the Darier Disease International Task Force (DDITF), consolidates current knowledge on the genetic basis, molecular pathophysiology, clinical presentation, diagnosis and management of DD, offering a global perspective that unites shared expertise. The disease arises from pathogenic variants in the ATP2A2 gene, which encodes sarco/endoplasmic reticulum Ca 2+ ‐ATPase isoform 2 (SERCA2), leading to disrupted calcium homeostasis and impaired desmosomal integrity. Clinically, DD is classified based on lesion type (classic vs. non‐classic) and is often accompanied by significant extracutaneous manifestations. Management remains challenging and requires a multifaceted approach, including topical therapies, systemic retinoids and lifestyle modifications. Emerging treatments that target the underlying molecular mechanisms offer promise for improved outcomes. This review aims to provide an updated reference and practical guidance for clinicians involved in the care and study of DD.

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disease with a poorly understood pathogenesis. Through a molecularly driven precision medicine approach and an extensive mechanistic pathway analysis in PRP skin samples, compared to psoriasis, atopic dermatitis, healed PRP, and healthy controls, we identified IL-1β as a key mediator, orchestrating an NF-κB–mediated IL-1β–CCL20 axis, including activation of CARD14 and NOD2. Treatment of three patients with the IL-1 antagonists anakinra and canakinumab resulted in rapid clinical improvement and reversal of the PRP-associated molecular signature with a 50% improvement in skin lesions after 2 to 3 weeks. This transcriptional signature was consistent with in vitro stimulation of keratinocytes with IL-1β. With the central role of IL-1β underscoring its potential as a therapeutic target, our findings propose a redefinition of PRP as an autoinflammatory keratinization disorder. Further clinical trials are needed to validate the efficacy of IL-1β antagonists in PRP.