LB1042 Neuroimmune Mediators of Pruritus in Scalp Psoriatic Itch: an Immunofluorescent Analysis in a Hispanic Population

Background: Scalp psoriatic itch is a prevalent yet understudied condition with numerous associated treatment challenges. Objective: The current study aims to enhance our understanding of scalp psoriatic itch pathophysiology in order to guide current management and identify novel treatment targets. Methods: Immunohistochemical analysis of known neuroimmune mediators of pruritus was conducted using scalp biopsies from 27 patients with scalp psoriasis. Patients were grouped per their itch NRS rating (taken at time of biopsy) into mild (NRS 1-3), moderate (NRS 4-6), and severe (NRS 7-10). Results: Intraepidermal nerve fiber (IENF) density, Substance P (SP), PAR2, TRPV3, TRPM8, and IL-23 expression were all significantly elevated in scalp psoriasis patients compared and significantly correlated with itch intensity. TRPV1, TNFα, and IL17 expression was increased in scalp psoriasis but did not correlate with itch intensity. Conclusion: Our results are congruent with prior data that scalp psoriasis pathophysiology is largely non-histaminergic and rather, driven by a Type 1 and IL-17 dominant immune response. Additionally, scalp psoriatic itch may have a greater neurological component than previously thought.