Deciphering the enigma of itch sensation: insights and impact from a readability study.

BACKGROUND: Itch terminology is ambiguous. How itch was described in online materials and how terminology influenced the readability of these materials was previously unknown. MATERIALS AND METHODS: Two groups of search terms, itch and prurigo, were translated into five of the most prevalent European Union (EU) languages. The itch group consisted of "itch" and "pruritus." The prurigo group consisted of "prurigo," "prurigo nodularis," and "chronic prurigo". Then, a search of the terms in each language was queried in the Google search engine in the private mode of the Internet browser. The first 50 results generated were assessed for suitability. Patient education was the primary objective of the materials provided, with no barriers or advertisements included. In cases where the terms yielded identical outcomes, any duplicated materials were omitted from the analysis. When translating search terms within a group led to just one shared transcription, the results were attributed to the search term with the most similar syntax. The Lix score was utilized to assess readability. RESULTS: 314 articles in English, German, Italian, French, and Spanish were evaluated. The term "pruritus" was the most commonly used description for the sensation of itching, with 142 (45%) articles included. Overall, the mean Lix score was 54 ± 9, classifying all articles as hard to comprehend. Articles in the itch group had significantly (P < 0.001) lower mean Lix score (52 ± 9) than materials in the prurigo group (56 ± 10). CONCLUSIONS: Despite being more accessible to conceptualize, skin conditions such as prurigo had lower readability compared to information about the itch itself. The distinction between "itch" and "pruritus" was unclear.

Increased cardiovascular risks and mortality in prurigo nodularis: a global cohort study.

BACKGROUND: Prurigo nodularis (PN) presents with intensely itchy hard nodules. Despite being limited to the skin, PN was noted to be associated with systemic diseases including diabetes and chronic renal failure. In previous smaller retrospective studies, several cardiac and vascular diseases were found more frequently in patients with PN. However, small cohort sizes, partially discrepant outcomes, missing data, and incomplete risk assessment limit these findings. METHODS: Electronic health records (EHR)s of 64,801 patients (59.44% females) with PN and an equal sized propensity-matched control group were retrieved. In these cohorts, the risks to develop cardiac and vascular diseases and mortality following the diagnosis of PN were determined. Sub-analyses included stratification for sex, ethnicity, and treatments. FINDINGS: PN was associated with a higher risk for a broad range of acute cardiac events including heart failure and myocardial infarction. For example, the hazard ratio of myocardial infarction was 1.11 (95%-CI: 1.041-1.184, p = 0.0015) following PN diagnosis. Also, all-cause mortality was higher in patients with PN. Further, chronic vascular as well as structural heart diseases, e.g., peripheral arterial disease, chronic ischaemic heart disease and valval disorders were found more frequently following a PN diagnosis. Risks were more pronounced in white and female patients. Having established an increased risk for death and cardiovascular disease, we next addressed if dupilumab that has been recently licenced for use in this indication can modulate these risks. The risk of death but not of any cardiovascular disease was slightly reduced in patients with PN treated with dupilumab as opposed to those treated with systemic therapies other than dupilumab. The study is limited by retrospective data collection and reliance on ICD10-disease classification. INTERPRETATION: PN is associated with higher mortality and an increased risk for the development of a wide range of cardiac and vascular diseases. Health care professionals should take this into account when managing patients with PN. FUNDING: This work was supported by the University of Lübeck, the Deutsche Forschungsgemeinschaft and the State of Schleswig-Holstein.

Prurigo: review of its pathogenesis, diagnosis, and treatment.

Prurigo is a reactive, hyperplastic skin condition characterized by pruritic papules, plaques, and/or nodules. The temporal classification includes acute/subacute and chronic disease (≥ 6 weeks), with different clinical variants, synonymies, and underlying etiological factors. The immunology of chronic prurigo shows similarities with atopic dermatitis due to the involvement of IL-4 and IL-13, IL-22, and IL-31. Treatment includes antihistamines, topical steroids, dupilumab, and JAK inhibitors. Several conditions manifest clinically as prurigo-like lesions, and the correct clinical diagnosis must precede correct treatment. Furthermore, chronic prurigos represent a recalcitrant and distressing dermatosis, and at least 50% of these patients have atopic diathesis, the treatment of which may induce adverse effects, especially in the elderly. The quality of life is significantly compromised, and topical treatments are often unable to control symptoms and skin lesions. Systemic immunosuppressants, immunobiologicals, and JAK inhibitors, despite the cost and potential adverse effects, may be necessary to achieve clinical improvement and quality of life. This manuscript reviews the main types of prurigo, associated diseases, their immunological bases, diagnosis, and treatment.

Successful treatment of refractory prurigo nodularis with abrocitinib.

Prurigo nodularis is frequently difficult to manage with conventional therapy. Given the pathogenesis and refractory nature, we demonstrate a case in which inhibition of JAK-STAT signaling may significantly improve prurigo nodularis. Based on the results, we would like to draw a conclusion that abrocitinib as an inhibitor of Jak is a promising choice for the treatment of prurigo nodularis.

Spatial mass cytometry-based single cell imaging reveals a disrupted epithelial-immune axis in prurigo nodularis.

Prurigo nodularis (PN) is a chronic, inflammatory skin condition that disproportionately affects African Americans and features intensely pruritic, hyperkeratotic nodules on the extremities and trunk. PN is understudied compared to other inflammatory skin diseases, with the spatial organization of the cutaneous infiltrate in PN yet to be characterized. In this work, we employ spatial imaging mass cytometry to visualize prurigo nodularis lesional skin inflammation and architecture with single cell resolution through an unbiased machine learning approach. PN lesional skin has increased expression of caspase 3, NFkB, and pSTAT3 as compared to healthy skin. Keratinocytes in lesional skin are subdivided into CD14+CD33+, CD11c+, CD63+, and caspase 3+ innate subpopulations. CD14+ macrophage populations expressing pERK1/2 correlate positively with patient-reported itch (p=0.006). Hierarchical clustering reveals a cluster of prurigo nodularis patients with greater atopy, increased NFkB+pSTAT3+pERK1/2+ MoDCs, and increased vimentin expression (p<0.05). Neighborhood analysis finds interactions between CD14+ macrophages, CD3+ T cells, MoDCs, and keratinocytes expressing innate immune markers. These findings highlight pERK+CD14+ macrophages as contributors to itch and suggest an epithelial-immune axis in prurigo nodularis pathogenesis.

[Translated article] Prurigiform Angiomatosis: A New Term for Describing the Prominent Dermal Angiomatoid Proliferation Underlying Epidermal Changes in Prurigo Nodularis/Lichen Simplex Chronicus.

Vascular hyperplasia is a common finding in prurigo nodularis/lichen simplex chronicus (LSC). The term prurigiform angiomatosis was recently proposed to describe a histologic pattern characterized by prominent vascular hyperplasia in patients with LSC. The aim of this study was to identify cases of LSC with this pattern and analyze associations with clinical and pathologic features and disease course. We reviewed 54 cases of histologically confirmed LSC and detected findings consistent with prurigiform angiomatosis in 10 (18.5%). The patients (7 men, 3 women) had a mean age of 59.7 years. The lesions were pruritic and predominantly located on the extremities and trunk. The most notable histologic finding was vascular proliferation in the superficial dermis associated with a lymphocytic inflammatory infiltrate. Recognition of prurigiform angiomatosis is important as it helps not only to distinguish LSC from other entities (mainly vascular tumors) but also to detect lesions that need to be surgically excised due to poor response to topical treatment.

Dysregulation of the Skin-Liver Axis in Prurigo Nodularis: An Integrated Genomic, Transcriptomic, and Population-Based Analysis.

Pruritus has long been linked to hepatic dysfunction; however, there are limited data characterizing the association between liver disease and prurigo nodularis (PN), a chronic inflammatory skin disease featuring severe pruritis. We thus conducted a cross-sectional analysis of hepatic comorbidities in PN patients using TriNetX, a large global health research network. This analysis revealed that PN patients had a higher risk (p < 0.001) of developing liver cirrhosis, acute and subacute hepatic failure, inflammatory liver disease, chronic hepatitis, nonalcoholic steatohepatitis, portal hypertension, fatty liver, chronic passive congestion of the liver, and hepatocellular carcinoma compared with healthy controls. The cumulative incidence of liver disease was about three times higher in PN patients compared with healthy controls. These findings provided the basis for translational studies to investigate a genetic mechanism for this association. Cutaneous transcriptomic analysis performed on PN patients revealed the dysregulation of genes related to hepatic failure in lesional PN compared with both nonlesional PN and control skin. Similarly, gene set variation analysis (GSVA) revealed a significantly increased (p < 0.05) activation of liver metabolism, chronic hepatic failure, acute hepatic failure, cholestatic liver disease, polycystic liver disease, and hepatocellular carcinoma pathways in lesional PN compared with control skin. A subsequent genome-wide association study (GWAS) identified shared single-nucleotide polymorphisms (SNPs) in the genes AR, EDIL3, MACROD2, PCSK5, RUNX1T1, TENM4, and ZEB2 between PN and liver disease from the FinnGen cohort. Significant dysregulation of the skin-liver axis in PN patients may explain the increased incidence and severity of hepatic comorbidities and help identify future therapeutic targets for PN.

A systematic review of interleukin-31 inhibitors in the treatment of prurigo nodularis.

BACKGROUND: Prurigo nodularis (PN) is a neuroimmunological skin disease. Severe itching is the most challenging symptom which affects patients' quality of life. T helper 2-derived cytokines, such as interleukin-31 and oncostatin M (OSM), play a crucial role in PN pathogenesis. Nemolizumab and vixarelimab are two biologics acting as IL-31 inhibitors. Vixarelimab also suppresses the OSM activity. This systematic review evaluates the efficacy and safety of nemolizumab and vixarelimab in PN management. METHODS: A systematic search was conducted in PubMed/Medline, Ovid Embase, and Web of Science up to September 17th, 2023. Clinical trials and cohort studies published in English were included. RESULTS: Among a total of 96 relevant records, five were included. The results of four studies with 452 patients using nemolizumab showed that a significantly higher percentage of patients treated with nemolizumab demonstrated a reduction in peak pruritus numerical rating scale (PP-NRS) and investigator's global assessment along with improved sleep disturbance (SD) and quality of life than the placebo group. Moreover, one study administered vixarelimab to 49 PN patients, and their finding illustrated a higher rate of subjects who received vixarelimab experienced ≥ 4-point diminution in worst itch NRS, visual analog scale, healing of representative lesions, and SD quality compared to the placebo group. CONCLUSIONS: IL-31 inhibitors suggest distinct advantages in improving pruritus, sleep quality, and overall quality of life in subjects with moderate-to-severe PN. Further clinical studies are recommended to compare the effectiveness of these biologics to other therapeutic choices.

Dupilumab for Treatment of Prurigo Nodularis: Real-Life Effectiveness for up to 84 Weeks.

(1) Background: Prurigo nodularis (PN) is a persistent and inflammatory dermatological condition characterized by chronic itching and the formation of hardened nodules, significantly impacting the affected individuals' quality of life and psychological well-being. The management of PN poses challenges due to the limited efficacy and undesirable side effects associated with current interventions. (2) Methods: This article examines sixteen patients affected by PN treated with dupilumab, a fully human monoclonal antibody targeting interleukin IL-4 and IL-13 signaling. This involves a retrospective descriptive statistical analysis. (3) Results and (4) Conclusions: In all patients, dupilumab proves to be an effective drug in achieving disease clearance, as indicated by all the parameters considered as assessed by both physicians and patients at each evaluation point (Week 6, Week 16, Week 32, Week 52, Week 68, and Week 84), in comparison to the initial baseline.

Actinic conjunctivitis and its relationship with prurigo in an indigenous population from the Highlands of Chiapas, Mexico.

PURPOSE: Actinic conjunctivitis (AC), along with cheilitis (AChe), is part of the clinical spectrum of actinic prurigo (AP), a rare photo dermatosis that affects high-risk populations. We analyzed the clinical manifestations and onset of actinic conjunctivitis (AC), and its relationship with prurigo (AP) in a susceptible population. METHODS: This prospective observational cohort study was performed on Indigenous populations from the highlands of Chiapas, Mexico. Thorough dermatological and ophthalmological examinations were performed in patients attending a primary health care center. The clinical features, labor and environmental factors, onset timing, and clinical staging of AC and AP were analyzed. RESULTS: Of the 2913 patients studied, 54 patients (108 eyes) (1.8%) had AC, and 14 patients (25.9%) had AP. The mean age at diagnosis was 36.18 ± 18.52 years (6-70 years). The mean residential altitude was 1884 ± 434.2 m above sea level. Mean self-reported sun exposure was 5.14 ± 3.1 h a day (0.5-12 h). A total of 90.7% reported exposure to biomass fuels during cooking, and 50% to farm animals. AC was the sole manifestation in 70% of the cases. All patients had nasal and temporal photo-exposed conjunctiva. Among the eyes, 12.9% were classified as stage-1, 64.8% as stage-2, and 22.2% stage-3. A total of 83.3% of the patients had hyperpigmented lesions, and 35.1% had evaporative dry eye disease. CONCLUSIONS: AC may be the initial or sole manifestation of AP. Most AC cases (87%) were initially observed at the advanced stages of the disease. Although solar exposure was not associated with late AC stages, a positive association was found with farm animal exposure. Evaporative dry eye associated with meibomian gland dysfunction has not been previously reported in patients with AC.

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.

Non-Systemic Medication for the Treatment of Prurigo Nodularis: A Systematic Review.

Prurigo nodularis (PN) is a skin disease characterized by firm, itchy, erythematous lesions. Treatment consists of systemic and non-systemic modes of therapy. Non-systemic forms of treatment are first-line and include topical corticosteroids, topical steroid-sparing agents, and phototherapy. The objective was to review the efficacy of non-systemic treatment used to treat PN. A systematic search was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered with PROSPERO (CRD42023412012). The search consisted of keywords and Medical Subject Heading (MeSH) terms and translated to Ovid MEDLINE, Embase, and Scopus. Google Scholar was also searched for the first 200 articles. Article quality of evidence was scored using GRADE criteria. The search yielded 1151 results; 37 met criteria for inclusion. There were 14 studies on phototherapy, and 11 studies on topical corticosteroids, most of which were also combined with topical antihistamines, antipruritics, and/or phototherapy. There were 2 studies each on topical antipruritics used in isolation, vitamin D analogues, and intralesional triamcinolone acetonide. There was 1 study each on topical pimecrolimus, tacrolimus, 2% dinitrochlorobenzene, cryotherapy, acupuncture, and the Paul Gerson Unna boot. Most were case reports and case series, although 2 randomized controlled trials on phototherapy and topical pimecrolimus were included. Corticosteroids had varying levels of positive response in patients and appeared more effective when used in combination or under occlusive dressing. Phototherapy is likely effective, but the risk of relapse is high. Cryotherapy may also be a lesion-directed agent to circumvent challenges to adherence and avoidance of systemic medication.

Clinical Characteristics and Treatment Outcomes of Prurigo Nodularis: A Retrospective Study.

BACKGROUND: Prurigo nodularis (PN) is a complex chronic skin disease characterized by severe pruritic nodules. PN is often associated with mental health disorders and chronic medical comorbidities. Until recently, PN treatment has been challenging and difficult. OBJECTIVES: This study aims to describe the demographic, clinical characteristics, and comorbidities associated with PN. Also, we aim to describe the effectiveness of systemic therapies, including methotrexate, cyclosporine, and narrow band ultraviolet (NB-UVB) in adult patients with PN. METHODS: This is a retrospective chart review of adult patients diagnosed with PN at Hamilton Health Science Center and/or McMaster University in Hamilton, Ontario, between 2015 and 2023. RESULTS: The study included 81 patients (57% female). The mean age was 52.8 years, and the mean age of PN diagnosis was 50 years. Reported symptoms included: itching (100%), dry skin (53%), pain (17%), and burning sensation (5%). Lower and upper extremities were the most common areas involved in 93% and 69%, respectively. Mental health disorders were present in 79% of patients, with depression (58%) and anxiety (52%) being the most common. Atopic dermatitis was the most common skin comorbidity noted. Treatments used included cyclosporine, and NB-UVB, and MTX, which resulted in significant improvement of pruritus in 38%, 35%, and 31% of patients, respectively, at week 16. CONCLUSIONS: PN is associated with increased risk of mental health disorders and other medical comorbidities. Cyclosporine, methotrexate, and NB-UVB therapy may be effective treatment options, however clinicians must consider the potential short- and long-term adverse effects of these treatments.