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Abtahi-Naeini B, Hemati E, Faghihi G, Shahmoradi Z, Paknazar F, Rastegarnasab F, Varshosaz J, Hadian M, Akbari M, Sabzghabaee AM. Efficacy of topical gabapentin in women with primary macular amyloidosis: A side-by-side triple-blinded randomized clinical trial. J Cosmet Dermatol 2024; 23:1677-1684. [PMID: 38291677 DOI: 10.1111/jocd.16180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/08/2023] [Accepted: 12/31/2023] [Indexed: 02/01/2024]
Abstract
BACKGROUND Primary cutaneous macular amyloidosis (PCMA) is a chronic pruritic cutaneous disease characterized by heterogeneous extracellular deposition of amyloid protein in the skin. AIMS This study aimed to evaluate the efficacy of topical 6% gabapentin cream for the treatment of patients with PCMA. MATERIALS AND METHODS In this triple-blind clinical trial, a total of 34 patients, who were diagnosed with PCMA, treated using two different strategies of topical gabapentin as the active group and vehicle cream as the control group. RESULTS Pruritus score reduction in both groups was statistically significant compared with the baseline value (p < 0.001). There was a significant pigmentation score reduction in intervention group compared with control group after 1 month of the study (p < 0.001). The differences of pigmentation score changes between the groups were not significant at month 2 (p = 0.52) and month 3 (p = 0.22). CONCLUSIONS The results of this study suggest that topical gabapentin cream may be effective as a topical agent in the treatment of pruritus associated with PCMA without any significant adverse effects. It is recommended to perform similar studies with a larger sample size and longer duration in both sexes.
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Affiliation(s)
- Bahareh Abtahi-Naeini
- Pediatric Dermatology Division of Department of Pediatrics, Imam Hossein Children's Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
- Skin Diseases and Leishmaniasis Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Elahe Hemati
- Pediatric Dermatology Division of Department of Pediatrics, Imam Hossein Children's Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Gita Faghihi
- Skin Diseases and Leishmaniasis Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Zabihollah Shahmoradi
- Skin Diseases and Leishmaniasis Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Fatemeh Paknazar
- Social Determinants of Health Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | | | - Jaleh Varshosaz
- Department of Pharmaceutics, Faculty of Pharmacy and Novel Drug Delivery Systems Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mahdi Hadian
- Skin Diseases and Leishmaniasis Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mojtaba Akbari
- Department of Epidemiology, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ali Mohammad Sabzghabaee
- Isfahan Clinical Toxicology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
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Okutani H, Lo Vecchio S, Arendt-Nielsen L. Mechanisms and treatment of opioid-induced pruritus: Peripheral and central pathways. Eur J Pain 2024; 28:214-230. [PMID: 37650457 DOI: 10.1002/ejp.2180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/08/2023] [Accepted: 08/22/2023] [Indexed: 09/01/2023]
Abstract
BACKGROUND AND OBJECTIVE Pruritus (also known as itch) is defined as an unpleasant and irritating sensation of the skin that provokes an urge to scratch or rub. It is well known that opioid administration can cause pruritus, which is paradoxical as itch and pain share overlapping sensory pathways. Because opioids inhibit pain but can cause itching. Significant progress has been made to improve our understanding of the fundamental neurobiology of itch; however, much remains unknown about the mechanisms of opioid-induced pruritus. The prevention and treatment of opioid-induced pruritus remains a challenge in the field of pain management. The objective of this narrative review is to present and discuss the current body of literature and summarize the current understanding of the mechanisms underlying opioid-induced pruritus, and its relationship to analgesia, and possible treatment options. RESULTS The incidence of opioid-induced pruritus differs with different opioids and routes of administration, and the various mechanisms can be broadly divided into peripheral and central. Especially central mechanisms are intricate, even at the level of the spinal dorsal horn. There is evidence that opioid receptor antagonists and mixed agonist and antagonists, especially μ-opioid antagonists and κ-opioid agonists, are effective in relieving opioid-induced pruritus. Various treatments have been used for opioid-induced pruritus; however, most of them are controversial and have conflicting results. CONCLUSION The use of a multimodal analgesic treatment regimen combined with a mixed antagonist and κ agonists, especially μ-opioid antagonists, and κ-opioid agonists, seems to be the current best treatment modality for the management of opioid-induced pruritus and pain. SIGNIFICANCE Opioids remain the gold standard for the treatment of moderate to severe acute pain as well as cancer pain. It is well known that opioid-induced pruritus often does not respond to regular antipruritic treatment, thereby posing a challenge to clinicians in the field of pain management. We believe that our review makes a significant contribution to the literature, as studies on the mechanisms of opioid-induced pruritus and effective management strategies are crucial for the management of these patients.
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Affiliation(s)
- Hiroai Okutani
- Center for Neuroplasticity and Pain, SMI, Department of Health Science and Technology, School of Medicine, Aalborg University, Aalborg, Denmark
- Department of Anesthesiology and Pain Medicine, Hyogo Medical University, Nishinomiya, Hyogo, Japan
| | - Silvia Lo Vecchio
- Center for Neuroplasticity and Pain, SMI, Department of Health Science and Technology, School of Medicine, Aalborg University, Aalborg, Denmark
| | - Lars Arendt-Nielsen
- Center for Neuroplasticity and Pain, SMI, Department of Health Science and Technology, School of Medicine, Aalborg University, Aalborg, Denmark
- Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
- Steno Diabetes Center North Denmark, Clinical Institute, Aalborg University Hospital, Aalborg, Denmark
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Meltan S, Panuganti B, Tarbox M. Evaluation and Management of Pruritus and Scabies in the Elderly Population. Clin Geriatr Med 2024; 40:91-116. [PMID: 38000864 DOI: 10.1016/j.cger.2023.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2023]
Abstract
Pruritus is the most common dermatologic complaint in the geriatric population. Its growing prevalence coincides with the rapid growth of the elderly population (>65 years of age) in the United States. According to the US Census Bureau, 16.9% of the population, or more than 56 million adults 65 years and older, lived in the United States in 2022. Pruritus is a condition that accompanies a diverse array of underlying etiologic factors. The mechanism of normal itch impulse transmission has been recently elucidated. The itch sensation originates from epidermal/dermal receptors connected to unmyelinated, afferent C-fibers that transmit the impulse from the periphery.
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Affiliation(s)
- Shakira Meltan
- School of Medicine, Texas Tech University Health Sciences Center, TX, USA
| | | | - Michelle Tarbox
- Department of Dermatology, Texas Tech Health Science Center, 3601 4th Street, Stop 9400, Lubbock, TX 79430, USA.
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Gurnani P, Miloh T, Chandar J, Landau DA, Hajjar F, Yosipovitch G. Systemic causes of non-dermatologic chronic pruritus in the pediatric population and their management: An unexplored area. Pediatr Dermatol 2021; 38:1051-1060. [PMID: 34515372 DOI: 10.1111/pde.14596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chronic pruritus associated with systemic diseases in the pediatric population has been infrequently addressed in the literature. This review focuses on chronic pruritus presenting without cutaneous manifestations. Common systemic etiologies include diseases with hepatic, renal, and hematologic origins. This encompasses several congenital liver disorders, end-stage renal disease (ESRD), and lymphoproliferative disorders such as Hodgkin's lymphoma. In this paper, an expert panel describes the clinical characteristics, pathophysiology, and therapeutic treatment ladders for chronic pruritus associated with the aforementioned systemic etiologies. Novel therapies are also reviewed. Our aim is to shed light on this unexplored area of pediatric dermatology and instigate further research.
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Affiliation(s)
- Pooja Gurnani
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery & Miami Itch Center, University of Miami, Miller School of Medicine, Miami, FL, USA.,Florida International University, Herbert Wertheim College of Medicine, Miami, FL, USA
| | - Tamir Miloh
- Pediatric Transplant Hepatology, Miami Transplant Institute, Jackson Health System, Miami, FL, USA
| | - Jayanthi Chandar
- Pediatric Kidney Transplantation, Miami Transplant Institute, Jackson Health System, Miami, FL, USA
| | | | - Fouad Hajjar
- AdventHealth For Children Pediatric Oncology and Hematology, Orlando, FL, USA
| | - Gil Yosipovitch
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery & Miami Itch Center, University of Miami, Miller School of Medicine, Miami, FL, USA
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Jafferany M, Davari ME. Itch and psyche: psychiatric aspects of pruritus. Int J Dermatol 2018; 58:3-23. [PMID: 29917231 DOI: 10.1111/ijd.14081] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 04/07/2018] [Accepted: 05/16/2018] [Indexed: 01/02/2023]
Abstract
Itch, also referred to as pruritus, is an unpleasant cutaneous sensation provoking the desire to scratch. It is often an uncomfortable, subjective sensation responsible for decreased quality of life in a variety of psychodermatological conditions. Comorbid psychiatric conditions, including depression and anxiety, are frequently associated with itch and scratch cycle. The reciprocal and intricate relationship between the psyche and itch has been widely studied. The neurobiology of itch involves the complexity of specific mediators, itch-related neuronal pathways, and central processing of itch. The connection between itch and the psyche can be grouped under three headings: pruritic diseases with psychosocial sequelae, pruritic diseases aggravated by psychosocial factors, and psychiatric disorders causing pruritus. Itch and pain modulation go together in most circumstances and involve various substances including histamine, interleukins, protease-activated receptors, transient receptor potential receptors, opioids, and cannabinoids. The close interaction between keratinocytes and nerve endings modulating pain and itch also play a major role. Management of itch associated with its psychosomatic components is directed at an underlying cause and adopting a holistic approach to address not only dermatologic and somatosensory aspects, but also the cognitive, emotional, and psychosocial components. An integrated multidisciplinary team consisting of a dermatologist, psychiatrist, psychologist, and social worker is vital in addressing the multifaceted aspects of pruritus.
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Nayak MK, Kapadia JD, Desai CK, Desai MK, Shah BJ. An Evaluation of Efficacy and Safety of Commonly Prescribed Drugs and Effect of These Drugs on Quality of Sleep in Patients Suffering From Zoster-Associated Pain. J Clin Pharmacol 2018; 58:1406-1417. [PMID: 29799622 DOI: 10.1002/jcph.1255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 04/06/2018] [Indexed: 12/12/2022]
Abstract
This observational, prospective, single-center study was conducted to evaluate the efficacy and safety of commonly prescribed drugs for zoster-associated pain and their impact on quality of sleep at a tertiary care hospital in western India. Patients ≥18 years of age, newly diagnosed with zoster-associated pain were evaluated on days 0, 7, 14, 30, 60, 90, 120, 150, and 180 or until resolution of pain, whichever was earlier, using the Wong Baker FACES Pain Rating Scale, Neuropathic Pain Scale, and Insomnia Severity Index for intensity of pain, quality of pain, and quality of sleep, respectively. A total of 78 patients (46.0 [16.3] years) completed the study. They received nonsteroidal anti-inflammatory drugs (65), gabapentin (30), amitriptyline (27), and amitriptyline + gabapentin (21) for mean durations of 7.7 (3.0), 89.2 (7.2), 107.6 (46.3), and 104.5 (46) days, respectively. Improvement in the Wong Baker FACES Pain Rating Scale and Neuropathic Pain Scale score was similar among treatment groups except for a greater fall in Wong Baker FACES Pain Rating Scale score at days 7 and 120 and that in deep pain score at day 7 in combination treatment group vs the amitriptyline group. Clinically significant insomnia was detected in 35 patients at baseline and demonstrated progressive and similar improvement among groups. Treatment modification was required in 20 patients. Zoster-associated pain resolved in 69 patients. Nine adverse drug reactions, mostly mild, nonserious, and nonpreventable, were reported. To conclude, drugs commonly used for zoster-associated pain are effective and well tolerated. These have a similar effect on pain and quality of sleep, except for a possible greater effect of combination treatment in the early phase of intense and deep pain.
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Affiliation(s)
- Mithilesh K Nayak
- Department of Pharmacology, B. J. Medical College and Civil Hospital, Ahmedabad, Gujarat, India
| | - Jigar D Kapadia
- Department of Pharmacology, B. J. Medical College and Civil Hospital, Ahmedabad, Gujarat, India
| | - Chetna K Desai
- Department of Pharmacology, B. J. Medical College and Civil Hospital, Ahmedabad, Gujarat, India
| | - Mira K Desai
- Department of Pharmacology, B. J. Medical College and Civil Hospital, Ahmedabad, Gujarat, India
| | - Bela J Shah
- Department of Skin and Venereal Diseases, B. J. Medical College and Civil Hospital, Ahmedabad, Gujarat, India
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Campbell V, McGrath C, Corry A. Low-dose naltrexone: a novel treatment for Hailey-Hailey disease. Br J Dermatol 2018; 178:1196-1198. [PMID: 28991360 DOI: 10.1111/bjd.16045] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2017] [Indexed: 01/19/2023]
Abstract
Hailey-Hailey disease (chronic benign familial pemphigus) is a rare inherited dermatosis typically characterized by erosions at intertriginous sites preceded by minor trauma or stress. We report a case of treatment-resistant Hailey-Hailey disease having failed topical and oral steroids, prophylactic aciclovir and doxycycline, and systemic therapies including dapsone, acitretin and ciclosporin. Low-dose naltrexone 4·5 mg once daily was commenced following an incidental benefit in this patient's similarly affected sister. The clinical and psychological response to date has been considerable.
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Affiliation(s)
- V Campbell
- Department of Dermatology, Wing D, Belfast City Hospital, Lisburn Rd, Belfast, BT9 7AB, U.K
| | - C McGrath
- Department of Dermatology, Wing D, Belfast City Hospital, Lisburn Rd, Belfast, BT9 7AB, U.K
| | - A Corry
- Department of Dermatology, Wing D, Belfast City Hospital, Lisburn Rd, Belfast, BT9 7AB, U.K
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Abstract
The article is dedicated to the problem of children pathomimia. Autoaggressive injuries in pediatrics are very common; they have a variety of clinical manifestations and can be a symptom of severe mental disorders. The article describes in detail the mechanisms for the formation of autoaggressive behavior, provides a classification of psychodermatoses, and describes the clinical features of the course of pathomimia in childhood and adolescence. The authors focused on the frequently occurred forms of pathomimia, which are provoked by stress factors and are transient. An approach to the treatment of skin autolesions in children has been proved and it is noted that the general treatment of pathomimia will depend on the degree of severity and manifestations of mental illness, and external therapy of psychodermatoses will lead to accelerating the regeneration of the skin lesion as well as the preventing of secondary infection.
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Siemens W, Xander C, Meerpohl JJ, Buroh S, Antes G, Schwarzer G, Becker G. Pharmacological interventions for pruritus in adult palliative care patients. Cochrane Database Syst Rev 2016; 11:CD008320. [PMID: 27849111 PMCID: PMC6734122 DOI: 10.1002/14651858.cd008320.pub3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND This is an update of the original Cochrane review published in 2013 (Issue 6). Pruritus occurs in patients with disparate underlying diseases and is caused by different pathologic mechanisms. In palliative care patients, pruritus is not the most prevalent but is one of the most puzzling symptoms. It can cause considerable discomfort and affects patients' quality of life. OBJECTIVES To assess the effects of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients. SEARCH METHODS For this update, we searched CENTRAL (the Cochrane Library), and MEDLINE (OVID) up to 9 June 2016 and Embase (OVID) up to 7 June 2016. In addition, we searched trial registries and checked the reference lists of all relevant studies, key textbooks, reviews and websites, and we contacted investigators and specialists in pruritus and palliative care regarding unpublished data. SELECTION CRITERIA We included randomised controlled trials (RCTs) assessing the effects of different pharmacological treatments, compared with a placebo, no treatment, or an alternative treatment, for preventing or treating pruritus in palliative care patients. DATA COLLECTION AND ANALYSIS Two review authors independently assessed the identified titles and abstracts, performed data extraction and assessed the risk of bias and methodological quality. We summarised the results descriptively and quantitatively (meta-analyses) according to the different pharmacological interventions and the diseases associated with pruritus. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created 10 'Summary of findings' tables. MAIN RESULTS In total, we included 50 studies and 1916 participants in the review. We added 10 studies with 627 participants for this update. Altogether, we included 39 different treatments for pruritus in four different patient groups.The overall risk of bias profile was heterogeneous and ranged from high to low risk. However, 48 studies (96%) had a high risk of bias due to low sample size (i.e. fewer than 50 participants per treatment arm). Using GRADE criteria, we downgraded our judgement on the quality of evidence to moderate in seven and to low in three comparisons for our primary outcome (pruritus), mainly due to imprecision and risk of bias.In palliative care participants with pruritus of different nature, the treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, reduced pruritus by 0.78 points (numerical analogue scale from 0 to 10; 95% confidence interval (CI) -1.19 to -0.37; one RCT, N = 48, quality of evidence: moderate) compared to placebo.For participants suffering from uraemic pruritus (UP), gabapentin was more effective than placebo (visual analogue scale (VAS): 0 to 10), mean difference (MD) -5.91, 95% CI -6.87 to -4.96; two RCTs, N = 118, quality of evidence: moderate). The κ-opioid receptor agonist nalfurafine showed amelioration of UP (VAS 0 to 10, MD -0.95, 95% CI -1.32 to -0.58; three RCTs, N = 422, quality of evidence: moderate) and only few adverse events. Moreover, cromolyn sodium relieved UP participants from pruritus by 2.94 points on the VAS (0 to 10) (95% CI -4.04 to -1.83; two RCTs, N = 100, quality of evidence: moderate) compared to placebo.In participants with cholestatic pruritus (CP), data favoured rifampin (VAS: 0 to 100, MD -24.64, 95% CI -31.08 to -18.21; two RCTs, N = 42, quality of evidence: low) and flumecinol (RR > 1 favours treatment group; RR 1.89, 95% CI 1.05 to 3.39; two RCTs, N = 69, quality of evidence: low) and showed a low incidence of adverse events in comparison with placebo. The opioid antagonist naltrexone reduced pruritus for participants with CP (VAS: 0 to 10, MD -2.26, 95% CI -3.19 to -1.33; two RCTs, N = 52, quality of evidence: moderate) compared to placebo. However, effects in participants with UP were inconclusive (percentage difference -12.30%, 95% CI -25.82% to 1.22%, one RCT, N = 32). Furthermore, large doses of opioid antagonists (e.g. naltrexone) could be inappropriate in palliative care patients because of the risk of reducing analgesia.For participants with HIV-associated pruritus, it is uncertain whether drug treatment with hydroxyzine hydrochloride, pentoxifylline, triamcinolone or indomethacin reduces pruritus because the evidence was of very low quality (e.g. small sample size, lack of blinding). AUTHORS' CONCLUSIONS Different interventions tended to be effective for CP and UP. However, therapies for patients with malignancies are still lacking. Due to the small sample sizes in most meta-analyses and the heterogeneous methodological quality of the included trials, the results should be interpreted cautiously in terms of generalisability.
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Affiliation(s)
- Waldemar Siemens
- Faculty of Medicine, University of Freiburg, GermanyClinic for Palliative Care, Medical Center ‐ University of FreiburgRobert‐Koch‐Straße 3FreiburgGermany
| | - Carola Xander
- Faculty of Medicine, University of Freiburg, GermanyClinic for Palliative Care, Medical Center ‐ University of FreiburgRobert‐Koch‐Straße 3FreiburgGermany
| | - Joerg J Meerpohl
- Medical Center ‐ University of FreiburgCochrane GermanyBreisacher Straße 153FreiburgGermany79110
| | - Sabine Buroh
- University Medical CenterLibrary of the Center of SurgeryHugstetterstrasse 55FreiburgBaden‐WürttembergGermany79115
| | - Gerd Antes
- Medical Center ‐ University of FreiburgCochrane GermanyBreisacher Straße 153FreiburgGermany79110
| | - Guido Schwarzer
- Medical Center ‐ University of FreiburgCenter for Medical Biometry and Medical InformaticsStefan‐Meier‐Str. 26FreiburgGermanyD‐79104
| | - Gerhild Becker
- Faculty of Medicine, University of Freiburg, GermanyClinic for Palliative Care, Medical Center ‐ University of FreiburgRobert‐Koch‐Straße 3FreiburgGermany
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Ward RE, Veerula VL, Ezra N, Travers JB, Mousdicas N. Multilevel symmetric neuropathic pruritus (MSNP) presenting as recalcitrant “generalized” pruritus. J Am Acad Dermatol 2016; 75:774-781. [DOI: 10.1016/j.jaad.2016.05.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 05/11/2016] [Accepted: 05/19/2016] [Indexed: 11/29/2022]
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Pruritus in Systemic Diseases: A Review of Etiological Factors and New Treatment Modalities. ScientificWorldJournal 2015; 2015:803752. [PMID: 26240837 PMCID: PMC4512616 DOI: 10.1155/2015/803752] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 06/11/2015] [Accepted: 06/16/2015] [Indexed: 02/07/2023] Open
Abstract
Pruritus is the most frequently described symptom in dermatology and can significantly impair the patient's quality of life. In 10–50% of adults with persistent pruritus, it can be an important dermatologic clue for the presence of a significant underlying systemic disease such as renal insufficiency, cholestasis, hematologic disorder, or malignancy (Etter and Myers, 2002; Zirwas and Seraly, 2001). This review describes the presence of pruritus in different systemic diseases. It is quite important to discover the cause of pruritus for providing relief for the patients experiencing substantial morbidity caused by this condition.
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Rosa AC, Fantozzi R. The role of histamine in neurogenic inflammation. Br J Pharmacol 2014; 170:38-45. [PMID: 23734637 DOI: 10.1111/bph.12266] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 02/13/2013] [Accepted: 03/28/2013] [Indexed: 12/21/2022] Open
Abstract
The term 'neurogenic inflammation' has been adopted to describe the local release of inflammatory mediators, such as substance P and calcitonin gene-related peptide, from neurons. Once released, these neuropeptides induce the release of histamine from adjacent mast cells. In turn, histamine evokes the release of substance P and calcitonin gene-related peptide; thus, a bidirectional link between histamine and neuropeptides in neurogenic inflammation is established. The aim of this review is to summarize the most recent findings on the role of histamine in neurogenic inflammation, with particular regard to nociceptive pain, as well as neurogenic inflammation in the skin, airways and bladder.
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Affiliation(s)
- A C Rosa
- Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Italy.
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14
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Abstract
Pruritus is a troublesome side-effect of neuraxial (epidural and intrathecal) opioids. Sometimes it may be more unpleasant than pain itself. The prevention and treatment still remains a challenge. A variety of medications with different mechanisms of action have been used for the prevention and treatment of opioid-induced pruritus, with mixed results. The aim of this article is to review the current body of literature and summarize the current understanding of the mechanisms and the pharmacological therapies available to manage opioid-induced pruritus. The literature source of this review was obtained via PubMed, Medline and Cochrane Database of Systematic Reviews until 2012. The search results were limited to the randomized controlled trials, systemic reviews and non-systemic reviews.
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Affiliation(s)
- Kamal Kumar
- Department of Anesthesia, Schulich School of Medicine, London Health Sciences, Victoria Hospital, London, Ontario, Canada
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15
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Abstract
Research over the past 15 years has helped to clarify the anatomy and physiology of itch, the clinical features of neuropathic itch syndromes and the scientific underpinning of effective treatments. Two itch-sensitive pathways exist: a histamine-stimulated pathway that uses mechanically insensitive C-fibres, and a cowhage-stimulated pathway primarily involving polymodal C-fibres. Interactions with pain continue to be central to explaining various aspects of itch. Certain spinal interneurons (Bhlhb5) inhibit itch pathways within the dorsal horn; they may represent mediators between noxious and pruritic pathways, and allow scratch to inhibit itch. In the brain, functional imaging studies reveal diffuse activation maps for itch that overlap, but not identically, with pain maps. Neuropathic itch syndromes are chronic itch states due to dysfunction of peripheral or central nervous system structures. The most recognized are postherpetic itch, brachioradial pruritus, trigeminal trophic syndrome, and ischaemic stroke-related itch. These disorders affect a patient's quality of life to a similar extent as neuropathic pain. Treatment of neuropathic itch focuses on behavioural interventions (e.g., skin protection) followed by stepwise trials of topical agents (e.g., capsaicin), antiepileptic drugs (e.g., gabapentin), injection of other agents (e.g., botulinum A toxin), and neurostimulation techniques (e.g., cutaneous field stimulation). The involved mechanisms of action include desensitization of nerve fibres (in the case of capsaicin) and postsynaptic blockade of calcium channels (for gabapentin). In the future, particular histamine receptors, protease pathway molecules, and vanilloids may serve as targets for novel antipruritic agents.
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Affiliation(s)
- Amar Dhand
- Department of Neurology, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0114, USA
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16
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Xander C, Meerpohl JJ, Galandi D, Buroh S, Schwarzer G, Antes G, Becker G. Pharmacological interventions for pruritus in adult palliative care patients. Cochrane Database Syst Rev 2013:CD008320. [PMID: 23749733 DOI: 10.1002/14651858.cd008320.pub2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Pruritus is not the most prevalent but one of the most puzzling symptoms in palliative care patients. It can cause considerable discomfort and has a major impact on patients' quality of life. In the field of palliative care, pruritus is a symptom occurring in patients with disparate underlying diseases and based on different pathologic mechanisms but ending in the same phenomenon. The pathogenesis of pruritus is complex and not fully elucidated. Thus, it is still very difficult to treat pruritus effectively. Evidence-based treatment approaches are needed. OBJECTIVES The objective was to evaluate the efficacy of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients. SEARCH METHODS A systematic literature search up to January 2012 was performed and it was updated in August 2012. The following databases were searched: The Cochrane Library (CENTRAL, DARE, CDSR) (2012, issue 8 of 12); MEDLINE (1950 to August 2012); EMBASE (1980 to August 2012) and three other databases. In addition, we searched trials registries and checked the reference lists of all relevant studies, key textbooks, reviews, and websites, and contacted investigators and specialists in pruritus and palliative care regarding unpublished data. SELECTION CRITERIA We included randomised controlled trials assessing the effects of different pharmacological treatments on preventing or treating pruritus in palliative care patients. DATA COLLECTION AND ANALYSIS Two review authors independently assessed identified titles and abstracts. Three independent review authors performed assessment of all potentially relevant studies, data extraction, assessment of risk of bias and methodological quality. Results were summarised descriptively according to the different pharmacological interventions and the type of underlying pruritus. Where possible, results were presented in meta-analyses. MAIN RESULTS In total, 38 reports comprising 40 studies and 1286 participants were included in the review. Altogether, 30 different treatments for pruritus in four different patient groups were included.The findings of this review indicated that the treatment of pruritus for palliative care patients is challenging and requires an individualistic approach. Results showed that effective therapeutic choices have to be guided by the pathophysiology of the pruritus. Various forms of pruritus occur, especially in the field of palliative care, and sometimes the origin of the pruritus is difficult to determine. Therefore, identifying the underlying cause of pruritus is of prime importance in order to develop tailored treatment plans, even if in palliative care the treatment is focused towards the symptom and not necessarily the underlying disease.Results show that in palliative care patients with pruritus of different natures, treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, may be beneficial. For patients suffering from pruritus associated with HIV infection, indomethacin was described as the most effective drug, although the evidence was weak. For patients suffering from chronic kidney disease-associated pruritus, gabapentin may be an option. An alternative treatment for this patient group seems to be the κ-opioid receptor agonist nalfurafine, which has shown significant amelioration of pruritus and acceptable adverse effects. As they have exhibited a low incidence of adverse effects, rifampicin and flumecinol may be recommended for patients with cholestatic pruritus. The opioid antagonist naltrexone has been shown to offer a therapeutic alternative for patients suffering from uraemic or cholestatic pruritus. However, these drugs are often inappropriate in the palliative population because of the risk of reducing analgesia when giving high doses of naltrexone. AUTHORS' CONCLUSIONS The findings of this review indicate that the number of systemic and topical drugs used for the different subforms of pruritus is increasing. Different interventions have been shown to be effective in the treatment of pruritus of different origins. Nevertheless, an optimal therapy for pruritus is constrained due to the limited understanding of crucial itch mediators and receptors in the various subforms of itch. Ideal antipruritic therapies are still lacking, especially for palliative care patients.This systematic review also indicates that there is insufficient evidence to give any concrete recommendations regarding treatment of pruritus in palliative care patients. Due to the very small sample sizes and poor methodological quality of the majority of studies that were included, the results of this review need to be interpreted with caution. Furthermore, the generalizability is questionable. Additional studies, and particularly carefully designed treatment trials, are needed to provide valid evidence for adequate treatment of pruritus in palliative care patients.
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Affiliation(s)
- Carola Xander
- German Cochrane Centre, Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Freiburg,Germany.
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Abstract
Itch/pruritus can be very distressing in palliative care population and often is difficult to treat. Conventional antihistamines lack efficacy. Cutaneous and central pathogenesis of itch is extremely complex and unclear, making its treatment challenging. Neuronal mechanisms have been identified in the pathophysiology of itch hence providing a myriad of therapeutic options. It has been established that pruritus and pain neuronal pathway interact with each other, hence neuropathic analgesics like gabapentin has shown to be efficacious antipruritic therapeutic option. Gabapentin impedes transmitting nociceptive sensations to brain, thus also suppressing pruritus. Gabapentin is safe and found to be effective in uremic pruritus, cancer/hematologic causes, opiod-induced itch, brachioradial pruritis, burns pruritus, and pruritus of unknown origin. Further research is required in this area to establish whether gabapentin is consistently effective.
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Affiliation(s)
- Sheeba Anand
- Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
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Update on pruritic mechanisms of hypertrophic scars in postburn patients: the potential role of opioids and their receptors. J Burn Care Res 2011; 32:e118-25. [PMID: 21747328 DOI: 10.1097/bcr.0b013e3182223c32] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although itching (or pruritus) in a scar is a very common and distressing symptom and is increasingly being recognized as a significant obstacle in burn rehabilitation, the exact mechanisms underlying this symptom have not been elucidated; hence, a reliable therapy has not been established. Recent findings have suggested that itching caused by inflammatory dermatosis can be reduced by antihistamines, but histamine antagonists cannot block all types of pruritus (eg, neuropathic itch). This indicates the presence of a histamine-independent pathway for itch. Itch or pruritus may also be evoked by direct activation of opioid receptors, which have recently been identified in the skin. This article aims to assess the current state of knowledge regarding the role of opioids in the generation of itch in hypertrophic scars in postburn patients. To this end, the authors have reviewed the relevant literature and present some clinical data. The authors hope that this review will form the basis for future research to elucidate the mechanism and treatment of itch.
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Abstract
Chronic itch could be a presenting sign of malignancy. Pruritus of lymphoma is the common prototype of paraneoplastic itch and can precede other clinical signs by weeks and months. Paraneoplastic pruritus has also been associated with solid tumors and is an important clinical symptom in paraneoplastic skin diseases such as erythroderma, Grovers disease, malignant acanthosis nigricans, generalized granuloma annulare, Bazex syndrome, and dermatomyositis. In any case with high index of suspicion a thorough work-up is required. This review highlights the association between itch and malignancy and presents new findings related to pathophysiological mechanisms and the treatment of itch associated with malignancy. Combinative therapies reducing itch sensitization and transmission using selective serotonin and neuroepinephrine reuptake inhibitors, Kappa opioids, and neuroleptics are of prime importance in reducing this bothersome symptom.
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Affiliation(s)
- Gil Yosipovitch
- Department of Dermatology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA.
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Chang FL, Ho ST, Sheen MJ. Efficacy of mirtazapine in preventing intrathecal morphine-induced nausea and vomiting after orthopaedic surgery*. Anaesthesia 2011; 65:1206-11. [PMID: 21182602 DOI: 10.1111/j.1365-2044.2010.06561.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nausea and vomiting are frequent complications of intrathecal morphine. In this randomised, double-blind trial, we tested the efficacy of mirtazapine, an antidepressant that blocks receptors associated with vomiting, on the incidence of nausea and vomiting after intrathecal morphine. One hundred patients receiving spinal anaesthesia for lower limb surgery were assigned equally to take either an orally disintegrating form of 30 mg mirtazapine or matching placebo 1 h before surgery. Spinal anaesthesia was performed by injection of 15 mg isobaric bupivacaine 0.5% along with 0.2 mg preservative-free morphine. Nausea and vomiting were evaluated 3, 6, 12, 18 and 24 h after intrathecal morphine administration. The incidence of nausea and vomiting was significantly lower in patients receiving mirtazapine compared with placebo (26.5% vs 56.3%, respectively; p = 0.005). The mean (SD) onset time of postoperative nausea and vomiting was significantly delayed in mirtazapine patients: 9.4 (2.5) vs 5.2 (1.8) h, respectively; p < 0.0001. The severity of nausea and vomiting was also decreased after mirtazapine at the 3-6 h and 6-12 h periods. Our data indicate that pre-operative mirtazapine decreases the incidence, delays the onset and reduces the severity of nausea and vomiting induced by intrathecal morphine in patients undergoing spinal anaesthesia.
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Affiliation(s)
- F-L Chang
- Department of Anaesthesiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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Abstract
Pruritus remains a significant problem facing dermatologists and can be associated with various dermatoses and systemic derangements. At times, one can treat the underlying cutaneous or systemic process to alleviate itch. However, it is frequently challenging to identify the cause of a patient's itch and, in this situation, even more difficult to manage the symptom effectively. In this article, the authors discuss the approach to a patient with generalized pruritus without clinically obvious dermatoses. They also addresses mechanisms and management modalities of itch in common systemic diseases, including cholestasis, uremia, and neuropathic dysfunction.
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Affiliation(s)
- Jamison D Feramisco
- Department of Dermatology, University of California at San Francisco, 1701 Divisadero Street, 3rd floor, San Francisco, CA 94115, USA
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Wang H, Yosipovitch G. New insights into the pathophysiology and treatment of chronic itch in patients with end-stage renal disease, chronic liver disease, and lymphoma. Int J Dermatol 2010; 49:1-11. [PMID: 20465602 DOI: 10.1111/j.1365-4632.2009.04249.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Hui Wang
- Department of Dermatology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
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Yosipovitch G. Recent advances in pruritus - what we have learned and where are we headed. F1000 MEDICINE REPORTS 2010; 2. [PMID: 20948846 PMCID: PMC2950052 DOI: 10.3410/m2-39] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chronic pruritus is an emerging health problem with a significant impact on quality of life. Recent advances in our understanding of newly discovered pathways and receptors for itch have been made. It is hoped that recent advancements will also drive the development of novel therapies for this often-neglected and bothersome symptom.
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Affiliation(s)
- Gil Yosipovitch
- Department of Dermatology, Wake Forest University Health Sciences, Medical Center Boulevard Winston-Salem, NC 27157 USA
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Gonçalves F. Thalidomide for the control of severe paraneoplastic pruritus associated with Hodgkin's disease. Am J Hosp Palliat Care 2010; 27:486-7. [PMID: 20231735 DOI: 10.1177/1049909110362523] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A 22-year-old woman with nodular sclerosis type II Hodgkin lymphoma diagnosed in June 2001. She initially underwent chemotherapy with 6 cycles of ABVD (adriamycin, bleomycin, vincristine, dacarbazine) regimen, leading to clinical remission. As it relapsed, she was again treated with 2 different chemotherapy regimens. In November 2003, she underwent bone marrow autotransplantation, but it relapsed after 2 months. After that, she was treated with chemotherapy in monotherapy until November 2005. In December 2005, she was referred to palliative care. Her main symptom was very severe pruritus that interfered with all aspects of her life, making her scratch continuously and interfering in all aspects of her life. She was treated with loratadine, hydroxyzine, prednisolone, paroxetine, mirtazapine, cimetidine, and ondansetron, individually and in various combinations. She also underwent ultraviolet phototherapy. All trials failed and her pruritus remained at level 8 of 10 most of the time. In April 2006, she started on thalidomide, 200 mg at night. The pruritus significantly improved to a level of 3 of 10 but did not disappear completely. She was at last able to sleep properly at night. She remained with a low level of pruritus until her death in July 2008, at the same dose of thalidomide.
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Schmelz M. Itch and pain. Neurosci Biobehav Rev 2010; 34:171-6. [DOI: 10.1016/j.neubiorev.2008.12.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 12/15/2008] [Accepted: 12/15/2008] [Indexed: 11/28/2022]
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Sheen MJ, Ho ST, Lee CH, Tsung YC, Chang FL, Huang ST. Prophylactic mirtazapine reduces intrathecal morphine-induced pruritus. Br J Anaesth 2008; 101:711-5. [PMID: 18713761 DOI: 10.1093/bja/aen241] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Activation of the serotonergic system is an important factor in the pathogenesis of intrathecal morphine-induced pruritus. Mirtazapine is a new antidepressant that selectively blocks 5-HT(2) and 5-HT(3) receptors. We therefore tested the hypothesis that preoperative mirtazapine would reduce the incidence of intrathecal morphine-induced pruritus. METHODS One hundred and ten ASA I patients undergoing lower limb surgery under spinal anaesthesia were randomly allocated into two equal groups and received either mirtazapine 30 mg or an orally disintegrating placebo tablet 1 h before operation in a prospective, double-blinded trial. All patients received an intrathecal injection of 15 mg of 0.5% isobaric bupivacaine and 0.2 mg preservative-free morphine. The occurrence and the severity of pruritus were assessed at 3, 6, 9, 12, and 24 h after intrathecal morphine. RESULTS Pruritus was significantly more frequent in the placebo group compared with the mirtazapine group (75% vs 52%, respectively; P=0.0245). The time to onset of pruritus in the two groups was also significantly different. The patients who experienced pruritus in the placebo group had a faster onset time than that in the mirtazapine group [mean (sd): 3.2 (0.8) vs 7.2 (4.1) h, P<0.0001]. CONCLUSIONS Mirtazapine premedication prevents pruritus induced by intrathecal morphine in patients undergoing lower limb surgery with spinal anaesthesia.
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Affiliation(s)
- M J Sheen
- Department of Anaesthesiology, Tri-Service General Hospital, National Defense Medical Center, 325, Cheng-gong Road Section 2, Neihu, Taipei 11490, Taiwan.
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Shim WS, Oh U. Histamine-induced itch and its relationship with pain. Mol Pain 2008; 4:29. [PMID: 18667087 PMCID: PMC2519061 DOI: 10.1186/1744-8069-4-29] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 07/31/2008] [Indexed: 05/25/2023] Open
Abstract
Itch is one of the major complications of skin diseases. Although there are various substances that induce itch or pruritus, it is evident that histamine is the best known endogenous agent that evokes itch. Even though histamine-induced itch has been studied for some time, the underlying mechanism of itch is just beginning to emerge. Although various downstream signaling pathways of histamine receptors have been revealed, more studies are required to determine the cause of histamine-induced itch. It appears that itch and pain involve different neuronal pathways. Pain generally inhibits itch, which indicates an inter-communication between the two. Complex interactions between itch and pain may be expected based on reports on disease states and opioids. In this review, we discuss the molecular mechanism and the pharmacological aspects of histamine-induced itch. Especially, the underlying mechanism of TRPV1 (an anti-pruritus target) has been determined to some extent.
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Affiliation(s)
- Won-Sik Shim
- National Research Laboratory of Transporters Targeted Drug Design, Research Institute of Pharmaceutical Sciences, College of Pharmacy,Seoul National University, Seoul, 151-742, Korea.
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Sheen MJ, Ho ST, Lee CH, Tsung YC, Chang FL. Preoperative Gabapentin Prevents Intrathecal Morphine-Induced Pruritus After Orthopedic Surgery. Anesth Analg 2008; 106:1868-72. [DOI: 10.1213/ane.0b013e3181730130] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Binder A, Koroschetz J, Baron R. Disease mechanisms in neuropathic itch. ACTA ACUST UNITED AC 2008; 4:329-37. [PMID: 18461071 DOI: 10.1038/ncpneuro0806] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 03/04/2008] [Indexed: 12/26/2022]
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Yosipovitch G, Carstens E, McGlone F. Chronic itch and chronic pain: Analogous mechanisms. Pain 2007; 131:4-7. [PMID: 17524558 DOI: 10.1016/j.pain.2007.04.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 04/11/2007] [Indexed: 10/23/2022]
Affiliation(s)
- Gil Yosipovitch
- Department of Dermatology, Neurobiology and Anatomy, and Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA.
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McQueen DS, Noble MAH, Bond SM. Endothelin-1 activates ETA receptors to cause reflex scratching in BALB/c mice. Br J Pharmacol 2007; 151:278-84. [PMID: 17351652 PMCID: PMC2013956 DOI: 10.1038/sj.bjp.0707216] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE Endothelin-1 (ET-1) is present in murine and human skin and causes itch (pruritus) when injected in humans. This behavioural study examined the scratch reflex evoked by ET-1 in mice. EXPERIMENTAL APPROACH An automated detector was used to determine whether ET-1 causes reflex scratching, the behavioural correlate of itching, in BALB/c mice. Selective agonists and antagonists were used to probe the ET receptor(s) involved. KEY RESULTS ET-1 evoked dose-related reflex scratching lasting up to 20 min following intradermal injection (0.1-100 ng; 0.04-40 pmol). The ED(50) for ET-1 induced scratching was 2.1 ng and desensitization occurred with cumulative dosing. High doses of the ET(B) receptor agonist IRL1620 (10 microg; 5.5 nmol), also caused scratching (ED(50) 1.3 microg, 0.7 nmol). The ET(A) receptor antagonist BQ123 significantly reduced scratching evoked by ET-1 and IRL 1620, suggesting that both agonists caused scratching via an ET(A) receptor-dependent mechanism. The ET(B) receptor antagonist BQ788 significantly reduced scratching evoked by IRL1620 but had no effect on scratching evoked by ET-1. This indicated that activation of ET(B) receptors by high doses of ET(B) agonist, but not ET-1, can trigger scratching. CONCLUSION AND IMPLICATIONS ET-1 is a potent endogenous activator of reflex scratching (itch). Mechanisms for ET-induced scratching are considered, including direct action of ET-1 on pruriceptive nerve endings and indirect actions via release of endogenous mediators such as histamine from mast cells. ET-1 and ET(A) receptors, possibly also ET(B) receptors, are potential targets for developing specific anti-pruritic drugs to treat pruritic skin disorders such as atopic dermatitis.
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MESH Headings
- Animals
- Behavior, Animal/drug effects
- Dose-Response Relationship, Drug
- Endothelin A Receptor Antagonists
- Endothelin B Receptor Antagonists
- Endothelin-1/administration & dosage
- Endothelin-1/pharmacology
- Endothelins/administration & dosage
- Endothelins/pharmacology
- Female
- Injections, Intradermal
- Mice
- Mice, Inbred BALB C
- Oligopeptides/administration & dosage
- Oligopeptides/pharmacology
- Peptide Fragments/administration & dosage
- Peptide Fragments/pharmacology
- Peptides, Cyclic/administration & dosage
- Peptides, Cyclic/pharmacology
- Piperidines/administration & dosage
- Piperidines/pharmacology
- Pruritus/physiopathology
- Receptor, Endothelin A/agonists
- Receptor, Endothelin A/physiology
- Receptor, Endothelin B/agonists
- Receptor, Endothelin B/physiology
- Reflex/drug effects
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Affiliation(s)
- D S McQueen
- Division of Neuroscience, School of Biomedical Sciences, University of Edinburgh College of Medicine & Veterinary Medicine, University of Edinburgh, Edinburgh, UK.
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Abstract
The neurobiology of itch, which is formally known as pruritus, and its interaction with pain have been illustrated by the complexity of specific mediators, itch-related neuronal pathways and the central processing of itch. Scratch-induced pain can abolish itch, and analgesic opioids can generate itch, which indicates an antagonistic interaction. However, recent data suggest that there is a broad overlap between pain- and itch-related peripheral mediators and/or receptors, and there are astonishingly similar mechanisms of neuronal sensitization in the PNS and the CNS. The antagonistic interaction between pain and itch is already exploited in pruritus therapy, and current research concentrates on the identification of common targets for future analgesic and antipruritic therapy.
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Affiliation(s)
- Akihiko Ikoma
- Department of Dermatology, Kyoto University, Shogin-Kawahara-cho 54, Sakyo-ku, Kyoto 606-8507, Japan
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