Immune stimulus exposure as a trigger for the development of chronic pruritus and circulating blood type 2 inflammation.

Background: Chronic pruritus (CP) is a poorly characterized condition associated with intense pruritus without a primary skin eruption. This condition tends to emerge more commonly in older adults, and there is limited research on triggering factors. Objective: To explore the clinical characteristics and pathophysiology of CP following exposure to an immune stimulus. Methods: Clinical characteristics and plasma samples were collected from 15 patients who developed CP following an immune stimulus such as checkpoint inhibitors or vaccination. A multiplex panel was used to analyze plasma cytokine concentrations within these patients. Results: Most immunotherapy-treated patients experienced CP during treatment or after 21 to 60 days of receiving treatment, while vaccine-stimulated patients developed pruritus within a week of vaccination. Plasma cytokine analysis revealed elevated levels of 12 cytokines in patients with immune-stimulated CP compared to healthy controls. Notably, T helper 2 (Th2) related cytokines interleukin (IL)-5 (fold change 2.65; q < 0.25) and thymic stromal lymphopoietin (fold change 1.61 q < 0.25) were upregulated. Limitations: Limitations of this study include limited sample size, particularly in the plasma cytokine assay. Conclusions and Relevance: This study reveals triggers of CP development and describes alterations in blood Th2 markers in patients with CP, including IgE, increased blood eosinophils, and cytokines IL-5 and thymic stromal lymphopoietin.

Comprehensive plasma cytokine and chemokine profiling in prurigo nodularis reveals endotypes in Type 2 inflammation.

Prurigo nodularis (PN) is a chronic inflammatory skin disease that is associated with variability in peripheral blood eosinophil levels and response to T-helper 2 targeted therapies (Th2). Our objective was to determine whether circulating immune profiles with respect to type 2 inflammation differ by race and peripheral blood eosinophil count. Plasma from 56 PN patients and 13 matched healthy controls was assayed for 54 inflammatory biomarkers. We compared biomarker levels between PN and HCs, among PN patients based on absolute eosinophil count, and across racial groups in PN. Eleven biomarkers were elevated in PN versus HCs including interleukin (IL)-12/IL-23p40, tumor necrosis factor-alpha (TNF-α), Thymic stromal lymphopoietin (TSLP), and macrophage-derived chemokine (MDC/CCL22). Additionally, PN patients with AEC > 0.3 K cells/µL had higher Th2 markers (eotaxin, eotaxin-3, TSLP, MCP-4/CCL13), and African American PN patients had lower eosinophils, eotaxin, and eotaxin-3 versus Caucasian and Asian PN patients (p < 0.05 for all). Dupilumab responders had higher AEC (p < 0.01), were more likely to be Caucasian (p = 0.02) or Asian (p = 0.05) compared to African Americans, and more often had a history of atopy (p = 0.08). This study suggests that blood AEC > 0.3 K and Asian and Caucasian races are associated with Th2 skewed circulating immune profiles and response to Th2 targeted therapies.

Single-Cell RNA Sequencing Reveals Dysregulated POSTN+WNT5A+ Fibroblast Subclusters in Prurigo Nodularis.

Prurigo nodularis (PN) is an intensely pruritic, inflammatory skin disease with a poorly understood pathogenesis. We performed single-cell transcriptomic profiling of 28,695 lesional and nonlesional PN cells. Lesional PN has increased dysregulated fibroblasts (FBs) and myofibroblasts. FBs in lesional PN were shifted toward a cancer-associated FB-like phenotype, with POSTN+WNT5A+ cancer-associated FBs increased in PN and similarly so in squamous cell carcinoma. A multicenter cohort study revealed an increased risk of squamous cell carcinoma and cancer-associated FB-associated malignancies (breast and colorectal) in patients with PN. Systemic fibroproliferative diseases (renal sclerosis and idiopathic pulmonary fibrosis) were upregulated in patients with PN. Ligand-receptor analyses demonstrated an FB neuronal axis with FB-derived WNT5A and periostin interactions with neuronal receptors melanoma cell adhesion molecule and ITGAV. These findings identify a pathogenic and targetable POSTN+WNT5A+ FB subpopulation that may predispose cancer-associated FB-associated malignancies in patients with PN.

Attitudes Toward Utilization of Minimally Invasive Cosmetic Procedures in Black Women: Results of a Cross-sectional Survey.

This cross-sectional study was designed to better understand perceptions of beauty, antiaging, and cosmetic procedures among young Black women, particularly social media users. An in-depth questionnaire was developed and administered via social media platforms to Black women in the United States (N=352). Study participants were asked about their top cosmetic skin concerns, prior and current usage of minimally invasive cosmetic procedures, and their attitudes toward obtaining such procedures in the future. Attitudes regarding beauty and self-perceived aging also were obtained to better understand how this demographic views beauty with regard to aging. All results were further stratified by age. Our findings suggest that perceptions of antiaging, particularly with regard to sunscreen use, are changing among younger Black women.