Successful use of tralokinumab for the treatment of atopic dermatitis on the genitals.

BACKGROUND: Genital involvement in atopic dermatitis(AD) can have a significant impact on the patient's quality of life. However, inspection of genital areas is not usually conducted during routine examination and patients may be reluctant to inform the clinician or show this area. OBJECTIVE: to evaluate the efficacy of tralokinumab in AD patients with genital involvement. METHODS: Adult patients with moderate/severe AD and genital involvement receiving tralokinumab have been analyzed. Primary endpoints were EASI, DLQI, PP-NRS, genital-IGA (g-IGA) and genital itching (GI) at week 16. RESULTS: out of 48 patients with moderate/severe AD under treatment with tralokinumab, 12 patients (25%) showed a genital involvement. Seven patients reported itching in the genital area (58%), while none reported a positive history of genital infections. Median scores at T0 were EASI 17.5, PP-NRS 8 and DLQI 14. After 16 weeks of treatment, we observed a median EASI of 3, a median PP-NRS of 1 and a median DLQI of 1. Finally, concerning the genital response, after 16 weeks of treatment, we observed a statistically significant decrease in mean GI and g-IGA scores. CONCLUSION: despite the small size of our sample, tralokinumab can be considered as a valid treatment option for AD with genital involvement.

Clinical Presentation of Atopic Dermatitis.

Atopic dermatitis, commonly known as eczema, is a chronic inflammatory dermatosis that can affect individuals from infancy to adulthood. Also referred to as "the itch that rashes," atopic dermatitis is classically associated with significant pruritus that is accompanied by characteristic cutaneous and other clinical findings. The diagnosis of atopic dermatitis can be challenging due to the wide range of clinical presentations based on patient factors such as age, skin type, ethnicity, and other comorbid conditions. This chapter reviews the classical findings as well as the less common manifestations of atopic dermatitis.

Association of pruritus and chronic cough: an all of us database study.

PURPOSE: Based on a potential shared pathophysiology tied to mast cell activity and neurogenic inflammation that may link pruritus and chronic cough (CC), this study, leveraging the All of Us database, examines the association between the two conditions. MATERIALS AND METHODS: A nested case-control comparison was used to examine the association, identifying cases with SNOMED codes 418363000 (pruritus) and 68154008 (CC). Matching was performed on a 1:4 ratio by age, sex, and ethnicity using the MatchIt package in R, followed by maximum likelihood method to estimate odds ratios (ORs) and 95% confidence intervals from 2x2 contingency tables. RESULTS: CC patients (n = 2,388) were more than twice as likely to be diagnosed with pruritus (OR: 2.65) and pruritus patients (n = 22,496) were more than twice as likely to be diagnosed with CC (OR: 2.57), than respective matched controls. CONCLUSIONS: These results highlight the potential bidirectional relationship between CC and pruritus, suggesting possible shared immune and neural pathways. Treatments like difelikefalin and nalbuphine that modulate these pathways, alongside P2X3 targeting agents, are emerging as potential therapeutic approaches for itch and chronic cough given the possible interconnected pathophysiology. This study's insights into the associations between pruritus and CC may pave the way for targeted therapeutic strategies that address their shared mechanisms.

Anti-pruritic effect of L-carnitine against chloroquine-induced pruritus mediated via nitric oxide pathway.

BACKGROUND: Pruritus, or itching, is a distressing symptom associated with various dermatological and systemic diseases. L-carnitine (ßeta hydroxy-γ-tri methyl amino-butyric acid), is a naturally occurring substance, it controls numerous physiological processes. The present research aims to identify L-carnitine for its anti-pruritic effect via nitric oxide-dependent mechanism. METHODS: Chloroquine-induced pruritus serves as an experimental model to investigate possible therapeutic interventions. In this study, we evaluated the efficacy of L-carnitine in combating oxidative stress, nitric oxide, and inflammatory cytokines in a chloroquine-induced pruritus model. RESULTS: L-carnitine treatment significantly reduced scratching behavior compared to the disease group (***P < 0.001 vs. chloroquine group), indicating its antipruritic potential. The markers of oxidative stress, GST, GSH, Catalase, and LPO were dysregulated in the disease model, but administration of L-carnitine restored GST, GSH, and Catalase levels and decreased LPO levels (***P < 0.001 vs. chloroquine group), thereby alleviating oxidative stress. L-carnitine also reduced nitric oxide synthase (NOS) activity, suggesting that it modulates nitric oxide signaling pathways involved in pruritus. In addition, L-carnitine lowered levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), inflammatory marker nuclear factor kappa B (p-NFκB) and also reduces an inflammatory enzyme, cyclooxygenase-2 (COX-2), determined by ELISA (Enzyme-Linked Immunosorbent Assay) (***P < 0.001 vs. chloroquine group). It downregulates nNOS mRNA expression confirmed by real-time polymerase chain reaction (RT-PCR). CONCLUSION: These findings highlight the therapeutic effects of L-carnitine in alleviating chloroquine-induced pruritus.

Rapid and sustained improvements in itch and quality of life with upadacitinib plus topical corticosteroids in adults and adolescents with atopic dermatitis: 52-week outcomes from the phase 3 AD Up study.

Purpose: Atopic dermatitis (AD) adversely impacts quality of life (QoL). We evaluated the effect of upadacitinib, an oral selective Janus kinase inhibitor approved for moderate-to-severe AD, plus topical corticosteroids (+TCS) on patient-reported outcomes (PROs) over 52 weeks.Materials and methods: In the phase 3 AD Up study (NCT03568318), adults and adolescents with moderate-to-severe AD were randomized 1:1:1 to once-daily upadacitinib 15 mg, 30 mg, or placebo + TCS. Itch, skin pain/symptoms, sleep, QoL, daily activities, emotional state, mental health, and patient impressions of disease severity/improvement/treatment satisfaction were assessed.Results: This analysis included 901 patients. Within 1-2 weeks, PRO improvements were greater with both upadacitinib doses than with placebo (p <.05). Improvements increased through weeks 4-8; rates were generally maintained through week 52. At week 52, the proportion of patients with clinically meaningful improvements in itch (Worst Pruritus Numerical Rating Scale improvement ≥4), skin pain (AD Symptom Scale Skin Pain improvement ≥4), sleep (AD Impact Scale [ADerm-IS] Sleep improvement ≥12), daily activities (ADerm-IS Daily Activities improvement ≥14), and emotional state (ADerm-IS Emotional State improvement ≥11) ranged from 62.1%-77.7% with upadacitinib 15 mg + TCS and 71.3%-83.6% with upadacitinib 30 mg + TCS.Conclusions: Upadacitinib + TCS results in rapid, sustained improvements in burdensome AD symptoms and QoL.

FGF13 enhances the function of TRPV1 by stabilizing microtubules and regulates acute and chronic itch.

Itching is an aversive somatosensation that triggers the desire to scratch. Transient receptor potential (TRP) channel proteins are key players in acute and chronic itch. However, whether the modulatory effect of fibroblast growth factor 13 (FGF13) on acute and chronic itch is associated with TRP channel proteins is unclear. Here, we demonstrated that conditional knockout of Fgf13 in dorsal root ganglion neurons induced significant impairment in scratching behaviors in response to acute histamine-dependent and chronic dry skin itch models. Furthermore, FGF13 selectively regulated the function of the TRPV1, but not the TRPA1 channel on Ca2+ imaging and electrophysiological recordings, as demonstrated by a significant reduction in neuronal excitability and current density induced by TRPV1 channel activation, whereas TRPA1 channel activation had no effect. Changes in channel currents were also verified in HEK cell lines. Subsequently, we observed that selective modulation of TRPV1 by FGF13 required its microtubule-stabilizing effect. Furthermore, in FGF13 knockout mice, only the overexpression of FGF13 with a tubulin-binding domain could rescue TRP channel function and the impaired itch behavior. Our findings reveal a novel mechanism by which FGF13 is involved in TRPV1-dependent itch transduction and provide valuable clues for alleviating pathological itch syndrome.

Seladelpar: New hope for patients with primary biliary cholangitis.

The study by Hirschfield et al.1 demonstrated safety profile and clinically significant effectiveness of the peroxisome proliferator-activated receptor delta (PPARδ) agonist seladelpar in patients with primary biliary cholangitis, highlighting its plausible use as a second-line treatment to reduce disease activity and pruritus.

Atopic Dermatitis: Managing the Itch.

Atopic dermatitis has a substantial impact on sleep, appearance, psychological well-being, and other qualities of life. The visual appearance of lichenification, cheilitis, hyperpigmentation, ichthyosis, and erythema can be socially stigmatizing, and treatment of these symptoms is challenging. In managing pruritus in patients, practitioners should assess and document pruritus through questionnaires at each routine visit. Initially, practitioners should advise patients to employ nonpharmaceutical treatments such as emollients with wet wraps, elimination of triggers, changing scratching habits, and psychological interventions. If these methods of treatment are not successful or if the disease presentation is severe, pharmacological therapies should be employed. This chapter describes the therapeutic ladder for pruritus in atopic dermatitis and discusses each treatment modality in further detail for practitioners to advise their patients.First-line topical pharmaceutical agents include topical glucocorticoids and topical calcineurin inhibitors. Second-line topical agents include coal tar, menthol, capsaicin, or doxepin. After the use of topical agents has been exhausted, primary systemic agents can be applied. These include sedating antihistamines, nonsedating antihistamines, oral glucocorticoids, or cyclosporine A. Finally, neuromodulating or immunomodulating agents can be attempted, including SSRI/SNRIs, TCAs, immunosuppressants, neural modulators, and opioid receptor modulators. Outside of pharmacological treatments, phototherapy has been shown to provide a dramatic improvement of pruritus in atopic dermatitis and can be used at any stage of treatment including as a first-line agent.

Social interactions and olfactory cues are required for contagious itch in mice.

The phenomenon of contagious itch, observed in both humans and rodents, remains a topic of ongoing debate concerning its modulators and underlying pathways. This study delves into the relationship between contagious itch and familiar olfactory cues, a non-visual factor contributing to this intriguing behavior. Our findings showed that contagious itch in observer mice occurs during physical interaction with the cagemate itch-demonstrator but not with a stranger demonstrator or in a non-physical encounter condition. Notably, itch-experienced observer mice displayed an increased contagious itch behavior, highlighting the relevance of itch-associated memory in this phenomenon. Furthermore, anosmic observer mice, whether itch-naïve or itch-experienced, displayed no contagious itch behavior. These results demonstrate that the familiar olfactory cues, specifically cagemate body odors, are required for contagious itch behaviors in mice. In line with these behavioral findings, our study reveals increased activity in brain regions associated with olfaction, emotion, and memory during contagious itch, including the olfactory bulb, the amygdala, the hypothalamus, and the hippocampus, with this activity diminished in anosmic mice. In conclusion, our study unveils the critical role of familiar olfactory cues in driving contagious itch in mice, shedding light on the interplay between social factors, sensory perception, and memory in this phenomenon.

The relationship between fatigue, pruritus, and thirst distress with quality of life among patients receiving hemodialysis: a mediator model to test concept of treatment adherence.

Hemodialysis is a conservative treatment for end-stage renal disease. It has various complications which negatively affect quality of life (QOL). This study aimed to examine the relationship between fatigue, pruritus, and thirst distress (TD) with QOL of patients receiving hemodialysis, while also considering the mediating role of treatment adherence (TA). This cross-sectional study was carried out in 2023 on 411 patients receiving hemodialysis. Participants were consecutively recruited from several dialysis centers in Iran. Data were collected using a demographic information form, the Fatigue Assessment Scale, the Thirst Distress Scale, the Pruritus Severity Scale, the 12-Item Short Form Health Survey, and the modified version of the Greek Simplified Medication Adherence Questionnaire for Hemodialysis Patients. Covariance-based structural equation modeling was used for data analysis. The structural model and hypothesis testing results showed that all hypotheses were supported in this study. QOL had a significant inverse association with fatigue, pruritus, and TD and a significant positive association with TA. TA partially mediated the association of QOL with fatigue, pruritus, and TD, denoting that it helped counteract the negative association of these complications on QOL. This model explained 68.5% of the total variance of QOL. Fatigue, pruritus, and TD have a negative association with QOL among patients receiving hemodialysis, while TA reduces these negative associations. Therefore, TA is greatly important to manage the associations of these complications and improve patient outcomes. Healthcare providers need to assign high priority to TA improvement among these patients to reduce their fatigue, pruritus, and TD and improve their QOL. Further studies are necessary to determine the most effective strategies for improving TA and reducing the burden of complications in this patient population.

A systematic review of procedural modalities in the treatment of notalgia paresthetica.

BACKGROUND: Notalgia paresthetica (NP) is a rare condition characterized by localized pain and pruritus of the upper back, associated with a distinct area of hyperpigmentation. Given the lack of standardized treatment and the uncertain efficacy of available options, applying procedural methods is of growing interest in treating NP. AIMS: We sought to comprehensively evaluate the role of procedural treatments for NP. METHODS: We systematically searched PubMed/Medline, Ovid Embase, and Web of Science until November 14th, 2023. We also performed a citation search to detect all relevant studies. Original clinical studies published in the English language were included. RESULTS: Out of 243 articles, sixteen studies have reported various procedural modalities, with or without pharmacological components, in treating NP. Pharmacological procedures, including injections of botulinum toxin, lidocaine, and corticosteroids, led to a level of improvement in case reports and case series. However, botulinum toxin did not show acceptable results in a clinical trial. Moreover, non-pharmacological procedures were as follows: physical therapy, exercise therapy, kinesiotherapy, acupuncture and dry needling, electrical muscle stimulation, surgical decompression, and phototherapy. These treatments result in significant symptom control in refractory cases. Physical therapy can be considered a first-line choice or an alternative in refractory cases. CONCLUSION: Procedural modalities are critical in the multidisciplinary approach to NP, especially for patients who are refractory to topical and oral treatments. Procedural modalities include a spectrum of options that can be applied based on the disease's symptoms and severity.

Patient preferences for treatment attributes in moderate-to-severe atopic dermatitis: a discrete choice experiment.

Purpose: Evidence on treatment preferences of patients with moderate-to-severe atopic dermatitis (AD) in the United States (US) is limited and an assessment of treatment preferences in this group is warranted.Materials and methods: An online discrete choice experiment survey was conducted (June 2023) among US adults with self-reported moderate-to-severe AD or experience with systemic therapy who had inadequate response to topical treatments. Preference weights estimated from conditional logistic regression models were used to calculate willingness to trade off and attributes' relative importance (RI).Results: Participants (N = 300; mean age: 45 years; 70% females; 52% systemic therapy experienced) preferred treatments with higher efficacy, lower risk of adverse events (AEs), and less frequent blood tests (p < .05). Treatment attributes, from high to low RI, were itch control (38%), risk of cancer (23%), risk of respiratory infections (18%), risk of heart problems (11%), sustained improvement in skin appearance (5%), blood test frequency (3%), and frequency and mode of administration (2%); together, AE attributes accounted for more than half of the RI.Conclusions: Participants preferred AD treatments that maximize itch control while minimizing AE risks, whereas mode of administration had little impact on preferences. Understanding patients' preferences may help improve shared decision-making, potentially leading to enhanced patient satisfaction with treatment, increased engagement, and better clinical outcomes.

Management of the Sequelae of Skin Grafting: Pruritis, Folliculitis, Pigmentation Changes, and More.

Scars commonly give rise to unpredictable, potentially irritating, cutaneous complications including pruritis, folliculitis, and pigment changes. These problems can be self-limiting and are prevalent in many burn cases, although their expression varies among individuals. A better understanding of the presentation, risk factors, and pathophysiology of these long-term sequelae allows for more comprehensive care of burn survivors.

Region-specific activation in the accumbens nucleus by itch with modified scratch efficacy in mice - a model-free multivariate analysis.

Itch is a protective/defensive function with divalent motivational drives. Itch itself elicits an unpleasant experience, which triggers the urge to scratch, relieving the itchiness. Still, it can also result in dissatisfaction when the scratch is too intense and painful or unsatisfactory due to insufficient scratch effect. Therefore, it is likely that the balance between the unpleasantness/pleasure and satisfaction/unsatisfaction associated with itch sensation and scratching behavior is determined by complex brain mechanisms. The physiological/pathological mechanisms underlying this balance remain largely elusive. To address this issue, we targeted the "reward center" of the brain, the nucleus accumbens (NAc), in which itch-responsive neurons have been found in rodents. We examined how neurons in the NAc are activated or suppressed during histamine-induced scratching behaviors in mice. The mice received an intradermal injection of histamine or saline at the neck, and the scratching number was analyzed by recording the movement of the bilateral hind limbs for about 45 min after injection. To experimentally manipulate the scratch efficacy in these histamine models, we compared histamine's behavioral and neuronal effects between mice with intact and clipped nails on the hind paws. As expected, the clipping of the hind limb nail increased the number of scratches after the histamine injection. In the brains of mice exhibiting scratching behaviors, we analyzed the expression of the c-fos gene (Fos) as a readout of an immediate activation of neurons during itch/scratch and dopamine receptors (Drd1 and Drd2) using multiplex single-molecule fluorescence in situ hybridization (RNAscope) in the NAc and surrounding structures. We performed a model-free analysis of gene expression in geometrically divided NAc subregions without assuming the conventional core-shell divisions. The results indicated that even within the NAc, multiple subregions responded differentially to various itch/scratch conditions. We also found different clusters with neurons showing similar or opposite changes in Fos expression and the correlation between scratch number and Fos expression in different itch/scratch conditions. These regional differences and clusters would provide a basis for the complex role of the NAc and surrounding structures in encoding the outcomes of scratching behavior and itchy sensations.

Prurigo Nodularis: Pathogenesis and the Horizon of Potential Therapeutics.

Chronic pruritus that lasts for over 6 weeks can present in various forms, like papules, nodules, and plaque types, with prurigo nodularis (PN) being the most prevalent. The pathogenesis of PN involves the dysregulation of immune cell-neural circuits and is associated with peripheral neuropathies, possibly due to chronic scratching. PN is a persistent and challenging condition, involving complex interactions among the skin, immune system, and nervous system. Lesional skin in PN exhibits the infiltration of diverse immune cells like T cells, eosinophils, macrophages, and mast cells, leading to the release of inflammatory cytokines and itch-inducing substances. Activated sensory nerve fibers aggravate pruritus by releasing neurotransmitters, perpetuating a vicious cycle of itching and scratching. Traditional treatments often fail, but recent advancements in understanding the inflammatory and itch transmission mechanisms of PN have paved the way for innovative therapeutic approaches, which are explored in this review.

MRGPRX4 mediates phospho-drug-associated pruritus in a humanized mouse model.

The phosphate modification of drugs is a common chemical strategy to increase solubility and allow for parenteral administration. Unfortunately, phosphate modifications often elicit treatment- or dose-limiting pruritus through an unknown mechanism. Using unbiased high-throughput drug screens, we identified the Mas-related G protein-coupled receptor X4 (MRGPRX4), a primate-specific, sensory neuron receptor previously implicated in itch, as a potential target for phosphate-modified compounds. Using both Gq-mediated calcium mobilization and G protein-independent GPCR assays, we found that phosphate-modified compounds potently activate MRGPRX4. Furthermore, a humanized mouse model expressing MRGPRX4 in sensory neurons exhibited robust phosphomonoester prodrug-evoked itch. To characterize and confirm this interaction, we further determined the structure of MRGPRX4 in complex with a phosphate-modified drug through single-particle cryo-electron microscopy (cryo-EM) and identified critical amino acid residues responsible for the binding of the phosphate group. Together, these findings explain how phosphorylated drugs can elicit treatment-limiting itch and identify MRGPRX4 as a potential therapeutic target to suppress itch and to guide future drug design.

Circadian rhythm of cutaneous pruritus. / 皮肤瘙痒的昼夜节律.

One of the most common and significant symptoms for skin disorders is pruritus. Additionally, it serves as a significant catalyst for the exacerbation or reoccurrence of skin diseases. Pruritus seriously affects patients' physical and mental health, and even the quality of life. It brings a heavy burden to the patients, the families, even the whole society. The pathogenesis and regulation mechanisms for pruritus are complicated and have not yet been elucidated. Previous clinical studies have shown that itch worsens at night in scabies, chronic pruritus, atopic dermatitis, and psoriasis, suggesting that skin pruritus may change with circadian rhythm. Cortisol, melatonin, core temperature, cytokines, and prostaglandins are the main regulatory factors of the circadian rhythm of pruritus. Recent studies have shown that some CLOCK genes, such as BMAL1, CLOCK, PER, and CRY, play an important role in the regulation of the circadian rhythm of pruritus by regulating the Janus tyrosine kinase (JAK)-signal transducer and activator of transcription (STAT) and nuclear factor kappa-B (NF-κB) signaling pathways. However, the mechanisms for circadian clock genes in regulation of circadian rhythm of pruritus have not been fully elucidated. Further studies on the mechanism of circadian clock genes in the regulation of circadian rhythm of pruritus will lay a foundation for elucidating the regulatory mechanisms for pruritus, and also provide new ideas for the control of pruritus and the alleviation of skin diseases.