-
Molecular Brain May 2024Itch is a protective/defensive function with divalent motivational drives. Itch itself elicits an unpleasant experience, which triggers the urge to scratch, relieving...
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.
Topics: Animals; Pruritus; Nucleus Accumbens; Histamine; Male; Mice, Inbred C57BL; Behavior, Animal; Proto-Oncogene Proteins c-fos; Neurons; Mice
PubMed: 38783364
DOI: 10.1186/s13041-024-01101-w -
Cureus Apr 2024Cholestasis of pregnancy (CP), or intrahepatic CP (ICP), represents a condition peculiar to pregnancy, marked by impaired bile acid flow and consequent accumulation in... (Review)
Review
Cholestasis of pregnancy (CP), or intrahepatic CP (ICP), represents a condition peculiar to pregnancy, marked by impaired bile acid flow and consequent accumulation in the maternal bloodstream. Primarily emerging in the third trimester, CP is linked with considerable risks to both the mother and fetus, including heightened incidences of preterm birth, fetal distress, and stillbirth, alongside maternal complications such as intense pruritus and liver dysfunction. Despite its clinical significance, the etiology of CP, which involves genetic, hormonal, and environmental factors, remains partially understood. This comprehensive review delves into the physiology and pathophysiology of CP, outlines its clinical manifestations and diagnostic criteria, and discusses the associated maternal and fetal complications. Furthermore, it evaluates current management strategies, prognostic implications, and potential long-term effects on maternal and child health. It also explores future research directions, emphasizing the need for advancements in understanding the pathophysiology of CP, developing novel therapeutic interventions, and improving risk stratification models. By offering a thorough overview of CP, this review aims to enhance clinical awareness, guide management practices, and identify areas requiring further investigation, ultimately contributing to better health outcomes for affected women and their babies.
PubMed: 38779244
DOI: 10.7759/cureus.58699 -
BMC Pharmacology & Toxicology May 2024Pruritus, or itching, is a distressing symptom associated with various dermatological and systemic diseases. L-carnitine (βeta hydroxy-γ-tri methyl amino-butyric...
BACKGROUND
Pruritus, or itching, is a distressing symptom associated with various dermatological and systemic diseases. L-carnitine (βeta 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.
Topics: Chloroquine; Pruritus; Nitric Oxide; Carnitine; Animals; Oxidative Stress; Male; Antipruritics; Signal Transduction; Mice; Cyclooxygenase 2; Cytokines
PubMed: 38778384
DOI: 10.1186/s40360-024-00748-4 -
Dermatology and Therapy Jun 2024Patients with moderate-to-severe atopic dermatitis (AD) who are most likely to respond to the Janus kinase (JAK) 1/2 inhibitor baricitinib (BARI) are known to have an...
INTRODUCTION
Patients with moderate-to-severe atopic dermatitis (AD) who are most likely to respond to the Janus kinase (JAK) 1/2 inhibitor baricitinib (BARI) are known to have an impacted body surface area (BSA) ≤ 40% and severe itch (numerical rating scale [NRS] ≥ 7], collectively termed 'BARI itch-dominant' patients. Our objective is to build on our previous work by providing a body region-specific, clinical characterization of the BARI itch-dominant patient at baseline and their response to BARI 4 mg.
METHODS
BREEZE-AD7 was a phase 3 trial in adults with moderate-to-severe AD receiving placebo or 2 mg or 4 mg BARI in combination with topical corticosteroids. Assessing only data from BARI itch-dominant patients, we summarized the baseline characteristics and conducted body region-specific analyses on Eczema Area and Severity Index (EASI) data in order to report the response to placebo versus BARI 4 mg within this patient subtype.
RESULTS
BARI 4 mg was highly effective across all body regions; at week 16, 75% improvement was seen in EASI scores (EASI75), and response rates with BARI 4 mg (head/neck, 58.3%; trunk, 69.2%; upper extremities, 61.5%; lower extremities, 87.5%) all exceeded those with placebo (head/neck: 37.5%; trunk, 40.6%; upper extremities, 18.8%; lower extremities, 40.6%) as well as the overall EASI75 rates of the intent-to-treat (ITT) population (BARI, 48.0%; placebo, 23.0%). At baseline, most BARI itch-dominant patients presented with involvement of all regions (mean regional BSA 22.7%-40.3%), highest in the head and neck, mean EASI region scores of 15.7-24.0, and considerably severe sign ratings (mean EASI sub-scores: 1.4-2.3, out of 3), especially for erythema.
CONCLUSION
BARI itch-dominant patients exhibit AD involvement across all body regions and considerable sign severity, especially erythema. In response to BARI 4 mg, EASI quickly improved across regions, substantially more so in this subtype than in the ITT population.
PubMed: 38777937
DOI: 10.1007/s13555-024-01171-7 -
Journal of the American Academy of... May 2024Tapinarof cream 1% once daily (QD), a topical aryl hydrocarbon receptor agonist, downregulates pro-inflammatory Th2 cytokines, upregulates skin-barrier components, and...
Tapinarof cream 1% once daily: Significant efficacy in the treatment of moderate to severe atopic dermatitis in adults and children down to 2 years of age in the pivotal phase 3 ADORING trials.
BACKGROUND
Tapinarof cream 1% once daily (QD), a topical aryl hydrocarbon receptor agonist, downregulates pro-inflammatory Th2 cytokines, upregulates skin-barrier components, and reduces oxidative stress.
OBJECTIVE
To assess tapinarof efficacy and safety in adults and children down to 2 years of age with atopic dermatitis (AD).
METHODS
Eight hundred and thirteen patients were randomized to tapinarof or vehicle QD in two 8-week phase 3 trials.
RESULTS
The primary efficacy endpoint, Validated Investigator Global Assessment for Atopic Dermatitis score of 0 or 1 and ≥2-grade improvement from baseline at Week 8, was met with statistical significance in both trials: 45.4% versus 13.9% and 46.4% versus 18.0% (tapinarof vs vehicle; both P < .0001). Significantly superior Eczema Area and Severity Index 75 (EASI75) responses were also observed with tapinarof versus vehicle at Week 8: 55.8% versus 22.9% and 59.1% versus 21.2% (both P < .0001). Rapid improvements in patient-reported pruritus were also significant with tapinarof versus vehicle. Common adverse events (≥5%) of folliculitis, headache, and nasopharyngitis were mostly mild or moderate, with lower discontinuations due to adverse events in the tapinarof groups than with vehicle.
LIMITATIONS
Long-term efficacy was not assessed.
CONCLUSION
Tapinarof demonstrated highly significant efficacy and favorable safety and tolerability in a diverse population of patients with AD down to 2 years of age.
PubMed: 38777187
DOI: 10.1016/j.jaad.2024.05.023 -
The Cochrane Database of Systematic... May 2024Sickle cell disease (SCD) refers to a group of genetic disorders characterized by the presence of an abnormal haemoglobin molecule called haemoglobin S (HbS). When... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Sickle cell disease (SCD) refers to a group of genetic disorders characterized by the presence of an abnormal haemoglobin molecule called haemoglobin S (HbS). When subjected to oxidative stress from low oxygen concentrations, HbS molecules form rigid polymers, giving the red cell the typical sickle shape. Antioxidants have been shown to reduce oxidative stress and improve outcomes in other diseases associated with oxidative stress. Therefore, it is important to review and synthesize the available evidence on the effect of antioxidants on the clinical outcomes of people with SCD.
OBJECTIVES
To assess the effectiveness and safety of antioxidant supplementation for improving health outcomes in people with SCD.
SEARCH METHODS
We used standard, extensive Cochrane search methods. The latest search date was 15 August 2023.
SELECTION CRITERIA
We included randomized and quasi-randomized controlled trials comparing antioxidant supplementation to placebo, other antioxidants, or different doses of antioxidants, in people with SCD.
DATA COLLECTION AND ANALYSIS
Two authors independently extracted data, assessed the risk of bias and certainty of the evidence, and reported according to Cochrane methodological procedures.
MAIN RESULTS
The review included 1609 participants in 26 studies, with 17 comparisons. We rated 13 studies as having a high risk of bias overall, and 13 studies as having an unclear risk of bias overall due to study limitations. We used GRADE to rate the certainty of evidence. Only eight studies reported on our important outcomes at six months. Vitamin C (1400 mg) plus vitamin E (800 mg) versus placebo Based on evidence from one study in 83 participants, vitamin C (1400 mg) plus vitamin E (800 mg) may not be better than placebo at reducing the frequency of crisis (risk ratio (RR) 1.18, 95% confidence interval (CI) 0.64 to 2.18), the severity of pain (RR 1.33, 95% CI 0.40 to 4.37), or adverse effects (AE), of which the most common were headache, nausea, fatigue, diarrhoea, and epigastric pain (RR 0.56, 95% CI 0.31 to 1.00). Vitamin C plus vitamin E may increase the risk of SCD-related complications (acute chest syndrome: RR 2.66, 95% CI 0.77 to 9.13; 1 study, 83 participants), and increase haemoglobin level (median (interquartile range) 90 (81 to 96) g/L versus 93.5 (84 to 105) g/L) (1 study, 83 participants) compared to placebo. However, the evidence for all the above effects is very uncertain. The study did not report on quality of life (QoL) of participants and their caregivers, nor on frequency of hospitalization. Zinc versus placebo Zinc may not be better than placebo at reducing the frequency of crisis at six months (rate ratio 0.62, 95% CI 0.17 to 2.29; 1 study, 36 participants; low-certainty evidence). We are uncertain whether zinc is better than placebo at improving sickle cell-related complications (complete healing of leg ulcers at six months: RR 2.00, 95% CI 0.60 to 6.72; 1 study, 34 participants; very low-certainty evidence). Zinc may be better than placebo at increasing haemoglobin level (g/dL) (MD 1.26, 95% CI 0.44 to 1.26; 1 study, 36 participants; low-certainty evidence). The study did not report on severity of pain, QoL, AE, and frequency of hospitalization. N-acetylcysteine versus placebo N-acetylcysteine (NAC) 1200 mg may not be better than placebo at reducing the frequency of crisis in SCD, reported as pain days (rate ratio 0.99 days, 95% CI 0.53 to 1.84; 1 study, 96 participants; low-certainty evidence). Low-certainty evidence from one study (96 participants) suggests NAC (1200 mg) may not be better than placebo at reducing the severity of pain (MD 0.17, 95% CI -0.53 to 0.87). Compared to placebo, NAC (1200 mg) may not be better at improving physical QoL (MD -1.80, 95% CI -5.01 to 1.41) and mental QoL (MD 2.00, 95% CI -1.45 to 5.45; very low-certainty evidence), reducing the risk of adverse effects (gastrointestinal complaints, pruritus, or rash) (RR 0.92, 95% CI 0.75 to 1.14; low-certainty evidence), reducing the frequency of hospitalizations (rate ratio 0.98, 95% CI 0.41 to 2.38; low-certainty evidence), and sickle cell-related complications (RR 5.00, 95% CI 0.25 to 101.48; very low-certainty evidence), or increasing haemoglobin level (MD -0.18 g/dL, 95% CI -0.40 to 0.04; low-certainty evidence). L-arginine versus placebo L-arginine may not be better than placebo at reducing the frequency of crisis (monthly pain) (RR 0.71, 95% CI 0.26 to 1.95; 1 study, 50 participants; low-certainty evidence). However, L-arginine may be better than placebo at reducing the severity of pain (MD -1.41, 95% CI -1.65 to -1.18; 2 studies, 125 participants; low-certainty evidence). One participant allocated to L-arginine developed hives during infusion of L-arginine, another experienced acute clinical deterioration, and a participant in the placebo group had clinically relevant increases in liver function enzymes. The evidence is very uncertain whether L-arginine is better at reducing the mean number of days in hospital compared to placebo (MD -0.85 days, 95% CI -1.87 to 0.17; 2 studies, 125 participants; very low-certainty evidence). Also, L-arginine may not be better than placebo at increasing haemoglobin level (MD 0.4 g/dL, 95% CI -0.50 to 1.3; 2 studies, 106 participants; low-certainty evidence). No study in this comparison reported on QoL and sickle cell-related complications. Omega-3 versus placebo Very low-certainty evidence shows no evidence of a difference in the risk of adverse effects of omega-3 compared to placebo (RR 1.05, 95% CI 0.74 to 1.48; 1 study, 67 participants). Very low-certainty evidence suggests that omega-3 may not be better than placebo at increasing haemoglobin level (MD 0.36 g/L, 95% CI -0.21 to 0.93; 1 study, 67 participants). The study did not report on frequency of crisis, severity of pain, QoL, frequency of hospitalization, and sickle cell-related complications.
AUTHORS' CONCLUSIONS
There was inconsistent evidence on all outcomes to draw conclusions on the beneficial and harmful effects of antioxidants. However, L-arginine may be better than placebo at reducing the severity of pain at six months, and zinc may be better than placebo at increasing haemoglobin level. We are uncertain whether other antioxidants are beneficial for SCD. Larger studies conducted on each comparison would reduce the current uncertainties.
Topics: Humans; Anemia, Sickle Cell; Antioxidants; Ascorbic Acid; Bias; Dietary Supplements; Oxidative Stress; Placebos; Quality of Life; Randomized Controlled Trials as Topic
PubMed: 38775255
DOI: 10.1002/14651858.CD013590.pub2 -
Clinical Case Reports May 2024Unlike most cases, the lesions were localized to the dorsum of the hand, lacked pruritus (itching), and did not exhibit "sperm-like blood vessels," which are typically...
KEY CLINICAL MESSAGE
Unlike most cases, the lesions were localized to the dorsum of the hand, lacked pruritus (itching), and did not exhibit "sperm-like blood vessels," which are typically pathognomonic to classical MF.
ABSTRACT
The study presents a rare case involving a 44-year-old woman who developed a skin condition on the base of her left thumb. Initially misdiagnosed as pigmented purpura, the need for further investigation arose to determine the nature of the condition accurately. The medical evaluation encompassed a comprehensive analysis of the patient's skin ailment. A series of diagnostic examinations were conducted to ascertain the underlying cause. Although routine blood tests yielded unremarkable results, the distinct characteristics of the rash prompted a more thorough investigation. Subsequent assessment revealed that the skin condition was not pigmented purpura, as initially presumed, but rather a manifestation of cutaneous T-cell lymphoma (CTCL) known as mycosis fungoides (MF). MF is an infrequent lymphoma predominantly affecting individuals aged 45-65, exhibiting a male-to-female sex ratio of 2:1. The annual incidence of MF ranges from 0.3 to 0.96 cases per 100,000 individuals. The woman's skin exhibited discrete patches adorned with colored dots, progressively thickening and pigmentation. Notably, the absence of pruritus did not dispel suspicion. This case underscores the significance of accurately diagnosing uncommon dermatological disorders to facilitate appropriate medical intervention. The unique appearance of the rash and its distinctive features, despite normal blood results, enabled the identification of MF. The patient's treatment encompassed a combination of steroids and narrowband UV therapy. Vigilance, continued research, and heightened awareness are paramount for early intervention and improved patient outcomes. Such efforts contribute to an enhanced understanding of the complexities of this condition.
PubMed: 38770416
DOI: 10.1002/ccr3.8847 -
Journal of Investigative Medicine High... 2024Cutaneous paraneoplastic syndromes due to Hodgkin lymphoma present with a wide spectrum of clinical manifestations from generalized pruritus to exfoliative erythroderma....
Cutaneous paraneoplastic syndromes due to Hodgkin lymphoma present with a wide spectrum of clinical manifestations from generalized pruritus to exfoliative erythroderma. We summarize the clinical findings and outcomes of 14 patients with Hodgkin lymphoma and associated cutaneous paraneoplastic syndromes treated at Mayo Clinic over the past 3 decades. Cutaneous paraneoplastic syndromes may be present at the time of lymphoma diagnosis, whereas in other patients, it may appear at the time of relapse, including patients with initial absence of cutaneous manifestations during the initial lymphoma presentation. Our results indicate that complete resolution of the paraneoplastic syndrome is associated with significantly improved overall survival. Recognition of cutaneous paraneoplastic syndromes is a crucial surrogate of relapsed malignancy and treatment requires targeting the underlying malignancy.
Topics: Humans; Hodgkin Disease; Paraneoplastic Syndromes; Male; Female; Middle Aged; Adult; Aged; Young Adult; Skin Diseases; Adolescent
PubMed: 38767173
DOI: 10.1177/23247096241255840 -
Kidney International Reports Apr 2024
PubMed: 38765577
DOI: 10.1016/j.ekir.2024.01.019 -
Cureus Apr 2024Vancomycin is a bactericidal antibiotic used for various infections but can cause hypersensitivity reactions, including vancomycin flushing syndrome (VFS) and...
Vancomycin is a bactericidal antibiotic used for various infections but can cause hypersensitivity reactions, including vancomycin flushing syndrome (VFS) and anaphylaxis. VFS, previously known as red man syndrome, is a pseudoallergic reaction characterized by flushing, erythema, and pruritus. We present a case of VFS in a female patient with recurrent Methicillin-resistant Staphylococcus aureus (MRSA) infections receiving vancomycin for back abscesses. Following the second dose, she developed a pruritic rash on her face, neck, and torso, which resolved with treatment. The differential diagnosis included hydromorphone allergy, ruled out due to previous tolerance. Anaphylaxis was unlikely due to the absence of respiratory distress, hypotension, or angioedema. Management involved discontinuing vancomycin, administering corticosteroids and antihistamines, and monitoring for anaphylaxis. The patient was transferred for surgical intervention and alternative antibiotic therapy. This case highlights the importance of recognizing and managing VFS, the significance of differential diagnoses, and the need for enhanced documentation and clinical support in managing vancomycin hypersensitivity reactions.
PubMed: 38765435
DOI: 10.7759/cureus.58487