학술논문
Scratching increases epidermal neuronal branching and alters psychophysical testing responses in atopic dermatitis and brachioradial pruritus.
Document Type
Academic Journal
Author
Renkhold L; Department of Dermatology and Centre for Chronic Pruritus, University Hospital Münster, Münster, Germany.; Wiegmann H; Department of Dermatology and Centre for Chronic Pruritus, University Hospital Münster, Münster, Germany.; Pfleiderer B; Clinic of Radiology, Medical Faculty, University Hospital Münster, University of Münster, Münster, Germany.; Süer A; Institute of Medical Informatics, University of Münster, Münster, Germany.; Zeidler C; Department of Dermatology and Centre for Chronic Pruritus, University Hospital Münster, Münster, Germany.; Pereira MP; Institute of Allergology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.; Allergology and Immunology, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Berlin, Germany.; Schmelz M; Department of Experimental Pain Research, MCTN, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany.; Ständer S; Department of Dermatology and Centre for Chronic Pruritus, University Hospital Münster, Münster, Germany.; Agelopoulos K; Department of Dermatology and Centre for Chronic Pruritus, University Hospital Münster, Münster, Germany.
Source
Publisher: Frontiers Research Foundation Country of Publication: Switzerland NLM ID: 101477914 Publication Model: eCollection Cited Medium: Print ISSN: 1662-5099 (Print) Linking ISSN: 16625099 NLM ISO Abbreviation: Front Mol Neurosci Subsets: PubMed not MEDLINE
Subject
Language
English
ISSN
1662-5099
Abstract
Background: Chronic scratching imposes a major stress on the skin and can lead to itch intensity worsening, and consequently, patients may enter an itch-scratch cycle. This repetitive mechanical stress can result in lichenification, worsening of epidermal barrier function, and enhanced cutaneous inflammation. Furthermore, a reduction of intraepidermal nerve fibers was previously described in lichenification.
Aim: The aim of this study was to investigate the influence of chronic scratching on the epidermal neuroanatomy and on sensory changes, in particular the prevalence of hyperknesis and alloknesis in patients after mechanical, chemical, and electrical stimuli.
Methods: Analyses were performed on pruritic lichenified (chronically scratched), pruritic non-lichenified (not chronically scratched), and non-pruritic non-lesional (unaffected) skin areas of patients with inflammatory pruritus, i.e., atopic dermatitis ( n = 35), and neuropathic pruritus, i.e., brachioradial pruritus ( n = 34) vs. healthy matched controls ( n = 64). Our fine-grained spatial skin characterization enabled specifically studying the differential effects of chronic scratching in inflammatory and neuropathic itch.
Results: Analysis of intraepidermal nerve fiber density showed rarefaction of fibers in all three skin areas of patients compared with healthy controls in both diagnoses. Even more, the two pruritic areas had significantly less nerve fibers than the unaffected skin, whereas electrically induced itch was massively increased. Epidermal branching of the remaining nerve fibers in lichenified/chronically scratched skin was increased, particularly in patients with brachioradial pruritus, which may contribute to the pronounced local neuronal sensitivity. Hyperknesis and alloknesis were found to increase independently of lichenification.
Conclusion: Our results indicate that chronic scratching may not affect intraepidermal nerve fiber density but leads to a stronger branching pattern of intraepidermal nerve fibers, which may contribute to local hypersensitivity. The increased sensitivity in the pruritic areas suggests mechanisms of peripheral sensitization, whereas the increased sensation of electrically and chemically induced itch in unaffected skin indicates central sensitization for itch.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
(Copyright © 2023 Renkhold, Wiegmann, Pfleiderer, Süer, Zeidler, Pereira, Schmelz, Ständer and Agelopoulos.)
Aim: The aim of this study was to investigate the influence of chronic scratching on the epidermal neuroanatomy and on sensory changes, in particular the prevalence of hyperknesis and alloknesis in patients after mechanical, chemical, and electrical stimuli.
Methods: Analyses were performed on pruritic lichenified (chronically scratched), pruritic non-lichenified (not chronically scratched), and non-pruritic non-lesional (unaffected) skin areas of patients with inflammatory pruritus, i.e., atopic dermatitis ( n = 35), and neuropathic pruritus, i.e., brachioradial pruritus ( n = 34) vs. healthy matched controls ( n = 64). Our fine-grained spatial skin characterization enabled specifically studying the differential effects of chronic scratching in inflammatory and neuropathic itch.
Results: Analysis of intraepidermal nerve fiber density showed rarefaction of fibers in all three skin areas of patients compared with healthy controls in both diagnoses. Even more, the two pruritic areas had significantly less nerve fibers than the unaffected skin, whereas electrically induced itch was massively increased. Epidermal branching of the remaining nerve fibers in lichenified/chronically scratched skin was increased, particularly in patients with brachioradial pruritus, which may contribute to the pronounced local neuronal sensitivity. Hyperknesis and alloknesis were found to increase independently of lichenification.
Conclusion: Our results indicate that chronic scratching may not affect intraepidermal nerve fiber density but leads to a stronger branching pattern of intraepidermal nerve fibers, which may contribute to local hypersensitivity. The increased sensitivity in the pruritic areas suggests mechanisms of peripheral sensitization, whereas the increased sensation of electrically and chemically induced itch in unaffected skin indicates central sensitization for itch.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
(Copyright © 2023 Renkhold, Wiegmann, Pfleiderer, Süer, Zeidler, Pereira, Schmelz, Ständer and Agelopoulos.)