P07 Shared pathophysiological pathways indicating treatment success of pityriasis rubra pilaris using anti-psoriatic anti-interleukin-17 therapy: a case report

Abstract Pityriasis rubra pilaris (PRP) is a rare and severe inflammatory skin disorder characterized by reddish-orange scaly patches with prominent follicular involvement. PRP is classified into six distinct clinical subtypes, one of which is genetic. This genetic subtype arises from a gain-of-function mutation of the CARD14 gene activating nuclear factor-kappa B (NFkB) typically located within the psoriasis susceptibility locus 2 (PSORS2) activating the IL13/IL17A cytokine axis.1 Similar to psoriasis, activation of the Th17/IL-23 inflammatory pathway presents diverse therapeutic opportunities beyond conventional therapies.2,3 Traditional therapies, such as high-dose vitamin A or methotrexate, are often associated with a number of adverse effects and limited tolerability.4 We present a case of a 35-year-old female with an unusual presentation of PRP-mimicking guttate psoriasis who showed remarkable improvement with an anti-psoriatic, anti-interleukin (IL)-17A antibody(Cosentyx®, Secukinumab, Novartis). Complete remission was achieved within 8 weeks of treatment and continued to display sustained efficacy and good tolerability. This case highlights the importance of considering PRP in the differential diagnosis of psoriasis-like lesions and the potential efficacy of targeted biologic therapies in its management.