Rxivist logo

Rxivist combines biology preprints from bioRxiv and medRxiv with data from Twitter to help you find the papers being discussed in your field. Currently indexing 161,564 papers from 674,550 authors.

Most downloaded biology preprints, all time

in category dermatology

61 results found. For more information, click each entry to expand.

1: Deep skin dysbiosis in vitiligo patients: link with mitochondrial and immune changes
more details view paper

Posted 30 Jul 2020

Deep skin dysbiosis in vitiligo patients: link with mitochondrial and immune changes
1,436 downloads medRxiv dermatology

Hanene Bzioueche, Kotryna Simonyte Sjodin, Christina E West, Abdallah Khemis, Stephane Rocchi, Thierry Passeron, Meri K Tulic

Rationale: Vitiligo is an autoimmune-disease characterized by patchy, white skin due to melanocyte loss. Commensal cutaneous or gut dysbiosis have been linked to various dermatological disorders. Here, we studied skin and gut microbiota of vitiligo patients compared to healthy controls. Methods: We recruited 20 subjects and obtained swabs and biopsies from lesional and non-lesional skin, stool and blood from each individual (total 100 samples). Results: We detected reduced richness and distribution of microbiota in stool of vitiligo subjects compared to controls (P<0.01). Skin swabs had greater alpha-diversity than skin biopsies (P<0.001), however only trends were seen between groups when examining microbiota at the skin surface. This was in contrast to sampling deeper layers of skin from the same patients which showed decreased richness and distribution of species (P<0.01) but greater phylogenetic diversity (P<0.01) in lesional compared to non-lesional sites. Biopsy microbiota from the lesional skin had distinct microbiota composition which was depleted of protective Bifidobacterium and enriched in Terenicutes, Streptococcus, Mycoplasma and mitochondrial DNA (P<0.001); the latter was linked with increased innate immunity and stress markers in the blood of the same patients (P<0.05). Conclusion: These data describe vitiligo-specific cutaneous and gut microbiota and, for the first time in humans, a link between mitochondrial alteration, innate immunity and skin microbiota.

2: Trends in Medicare Reimbursement, Use Rates, and Overall Expenditure for Skin Cancer Procedures: 2012-2017
more details view paper

Posted 30 May 2020

Trends in Medicare Reimbursement, Use Rates, and Overall Expenditure for Skin Cancer Procedures: 2012-2017
1,307 downloads medRxiv dermatology

Pranav Puri, Sujith Baliga, Mark R. Pittelkow, Puneet K. Bhullar, Aaron R. Mangold

The treatment of skin cancers represents a growing share of healthcare expenditures. At the same time, Medicare reimbursement rates for physician services have declined with respect to inflation. The objective of this study was to describe the economic effects of declining Medicare reimbursement for skin cancer procedures. In this ecological study, we used the Medicare Physician Supplier and Other Provider Public Use File (POSPUF) to analyze trends in Medicare reimbursement rates, use rates, and overall Medicare expenditures for skin cancer procedures from 2012 to 2017. We adjusted reimbursement rates for inflation by converting payment amounts into units of 2017 dollars. From 2012 to 2017, overall inflation-adjusted Medicare expenditure on skin cancer procedures increased 9%. Over this time period, inflation-adjusted Medicare reimbursement rates declined for each procedure class, with the exception of shave excision. Concurrently, the use rate of Mohs micrographic surgery increased 23%, while the use rate for all other skin cancer procedure classes declined. In summary, this study describes trends suggesting declining Medicare reimbursement rates have been associated with increasing use rates for higher cost skin cancer procedures. Clinicians and policy makers should collaborate to develop value-based payment models that incentivize patient outcomes rather than procedural volumes.

3: Effectiveness of four oral antifungal drugs (fluconazole, griseofulvin, itraconazole, terbinafine) in current epidemic of altered dermatophytosis in India: A randomized pragmatic trial
more details view paper

Posted 02 Aug 2019

Effectiveness of four oral antifungal drugs (fluconazole, griseofulvin, itraconazole, terbinafine) in current epidemic of altered dermatophytosis in India: A randomized pragmatic trial
1,277 downloads medRxiv dermatology

Sanjay Singh, Usha Chandra, Priyanka Verma, Vinayak N Anchan, Ragini Tilak

BackgroundDermatophyte infections have undergone unprecedented changes in India in recent past. Clinical trials comparing effectiveness of 4 main oral antifungal drugs are not available. We tested effectiveness of oral fluconazole, griseofulvin, itraconazole and terbinafine in chronic and chronic-relapsing tinea corporis, tinea cruris and tinea faciei. MethodsTwo hundred microscopy confirmed patients were allocated to 4 groups, fluconazole (5mg/kg/day), griseofulvin (10 mg/kg/day), itraconazole (5mg/kg/day), and terbinafine (7.5mg/kg/day), by concealed block randomization and treated for 8 weeks or cure. Effectiveness was calculated based on intention to treat analysis. ResultsAt 4 weeks, 4, 1, 2, and 4 patients were cured with fluconazole, griseofulvin, itraconazole and terbinafine, respectively (P=0.417). At 8 weeks, 21 (42%), 7 (14%), 33 (66%) and 14 (28%) patients were cured, respectively (P=0.000); itraconazole was superior to fluconazole, griseofulvin and terbinafine (P[&le;]0.016). Relapse rates after 4 and 8 weeks of cure in different groups were similar. Numbers-needed-to-treat (NNT) (versus griseofulvin), calculated based on cure rates at 8 weeks, for itraconazole, fluconazole, and terbinafine were 2, 4 and 8, respectively. ConclusionIn view of cure rates and NNT, itraconazole is the most effective drug, followed by fluconazole (daily), terbinafine and then griseofulvin, in chronic and chronic-relapsing dermatophytosis in India. One Sentence SummaryEffectiveness of all four antifungals has declined, with itraconazole being the most effective currently in dermatophytosis in India.

4: The spectrum of COVID-19-associated dermatologic manifestations: an international registry of 716 patients from 31 countries
more details view paper

Posted 25 May 2020

The spectrum of COVID-19-associated dermatologic manifestations: an international registry of 716 patients from 31 countries
1,223 downloads medRxiv dermatology

Esther E. Freeman, Devon E. McMahon, Jules B Lipoff, Misha Rosenbach, Carrie Kovarik, Seemal R Desai, Joanna Harp, Junko Takeshita, Lars E French, Henry W Lim, Bruce H Thiers, George J Hruza, Lindy P Fox

Question: What are the cutaneous manifestations associated with COVID-19 and do they provide insight into the pathophysiology or prognosis? Findings: In this international registry-based case series of 716 patients representing 31 countries, the most common dermatologic morphologies encountered in the 171 COVID-19 confirmed case included morbilliform, pernio-like, urticarial, macular erythema, vesicular, papulosquamous, and retiform purpura. Retiform purpura was seen exclusively in critically ill, hospitalized patients. Meaning: COVID-19 is associated with a spectrum of skin findings in affected patients. These cutaneous manifestations may vary depending on the severity of COVID-19.

5: High-resolution 3-D imaging for precise staging in malignant melanoma
more details view paper

Posted 27 Jul 2020

High-resolution 3-D imaging for precise staging in malignant melanoma
1,172 downloads medRxiv dermatology

Simon F. Merz, Philipp Jansen, Ricarda Ulankiewicz, Lea Bornemann, Tobias Schimming, Klaus Griewank, Zuelal Cibir, Andreas Kraus, Ingo Stoffels, Timo Aspelmeier, Sven Brandau, Dirk Schadendorf, Eva Hadaschik, Gernot Ebel, Matthias Gunzer, Joachim Klode

High-resolution imaging of sentinel lymph nodes (SLN) from melanoma patients is a crucial approach to specify staging and determine individuals requiring adjuvant treatment. Current histologic SLN analysis has the substantial drawback that only a small portion of the node is sampled while most of the tissue is discarded which might explain the high false-negative rate of SLN diagnosis. Therefore, we developed an algorithm-enhanced light sheet fluorescence microscopy (LSFM) approach to three-dimensionally reconstruct the entire SLN with the power to identify single tumor cells. We comprehensively quantified total tumor volume while simultaneously visualizing cellular and anatomical hallmarks of the associated SLN architecture. In a first-in-human prospective study (21 SLN from 11 melanoma patients), LSFM not only identified all metastases seen histologically, but additionally detected metastases not recognized by routine histology. Thus, our 3-D digital pathology approach can increase sensitivity and accuracy of SLN-metastasis detection and potentially alleviate the need for conventional histopathological assessment in the future.

6: The Impact of COVID-19 on Medical Practice: A Nationwide Survey of Dermatologists and Healthcare Providers in Iraq
more details view paper

Posted 04 Aug 2020

The Impact of COVID-19 on Medical Practice: A Nationwide Survey of Dermatologists and Healthcare Providers in Iraq
1,121 downloads medRxiv dermatology

Mohammed Shanshal, Hayder Saad Ahmed, Hayder Asfoor, Raad Ibrahim Salih, Shehab Ahmed Ali, Yusif k. Aldabouni

Background: The COVID-19 pandemic has dramatically changed medical practice worldwide. It posed a significant impact on different health services, including dermatology. Methods and objectives: Two online surveys were conducted to determine the prevalence of personal protective equipment-related skin complications (200 healthcare providers were included) and to demonstrate the outbreak s impact on dermatology practice (100 dermatologists were included). Results: In the first survey, the response rate was 72.46%. PPE- related dermatoses were reported by 147 (73%) participants, including frictional dermatitis (51.9%), mechanical acne (33.1%), contact dermatitis (29.9%), nonspecific rash (17.5%), urticaria (9.1%) and skin infections (3.2%). The response rate of the second survey was 64%. COVID-19 emerging cutaneous manifestations were recognized by 20% of dermatologists, including maculopapular rash (41.67%), urticaria (37.50%), chilblain (25%) and vasculitis (16.67). Telemedicine was provided by 73% of the dermatologists. The relapse rates of psoriasis, atopic dermatitis, rosacea, vitiligo and alopecia areata were noticeably increased as observed by 62%, 50%, 20%, and 4% of dermatologists, respectively. Most dermatologists (89%) reported minimal use of immunosuppressive drugs amid the pandemic. Conclusions: This article highlights the pivotal role of dermatologists in the leading edge during the current health crisis and how they adapt to these unfamiliar circumstances to meet the challenges. It documents the emergence of PPE-related dermatoses among healthcare providers and the impact of COVID-19 on different aspects of dermatology practice.

7: Futility of combining griseofulvin and terbinafine in current epidemic of altered dermatophytosis in India: Results of a randomized pragmatic trial
more details view paper

Posted 25 Sep 2019

Futility of combining griseofulvin and terbinafine in current epidemic of altered dermatophytosis in India: Results of a randomized pragmatic trial
1,101 downloads medRxiv dermatology

Sanjay Singh, Vinayak N Anchan, Radhika Raheja

BackgroundTreatment responsiveness of tinea has decreased considerably in recent past in India. We tested effectiveness of oral terbinafine plus griseofulvin versus terbinafine alone in tinea corporis, tinea cruris and tinea faciei in a randomized pragmatic open trial. MethodsOne hundred and thirty two microscopy confirmed patients were randomly allocated (ratio 1:1) to two groups, terbinafine (T) and terbinafine plus griseofulvin (T+G). Doses given were as follows: T, oral terbinafine (6 mg/kg/day, maximum 500 mg/day, once daily); T+G, terbinafine (as above) plus oral griseofulvin (children [<18 years] 10 mg/kg/day, adults [18 years or more] 10 mg/kg/day, but not <500 mg and not >1000 mg per day, in two divided doses). Patients were treated for 8 weeks or cure, whichever occurred earlier. ResultsAt 4 weeks, none of the patients were cured in both groups. At 6 weeks, 1(1.5%) and 4 (6.1%) patients were cured in T and T+G groups, respectively (P=0.417). At 8 weeks, 17 (25.8%) and 19 (28.8%) patients were cured in T and T+G groups, respectively (P=0.845). For cure rate at 8 weeks, number needed to treat (NNT) for T+G (versus T), was 33. ConclusionsAddition of griseofulvin to terbinafine does not increase effectiveness of terbinafine in current epidemic of altered dermatophytosis in India.

8: Incidence and Prevalence of Hidradenitis Suppurativa: A Systematic Review and Meta-analysis
more details view paper

Posted 22 Nov 2019

Incidence and Prevalence of Hidradenitis Suppurativa: A Systematic Review and Meta-analysis
1,018 downloads medRxiv dermatology

N. Gill, Robert Gniadecki

BackgroundHidradenitis is a chronic relapsing follicular occlusive disease with a widely variable reported prevalence. The exact prevalence and incidence of HS is unknown. ObjectivesTo perform a systematic review and meta-analysis of the published literature to estimate the global incidence and prevalence of HS. MethodsLiterature searches were performed on Medline, Embase, and Pubmed to identify studies reporting incidence and/or prevalence of HS. Pooled estimates of prevalence and incidence were calculated with a meta-analysis of proportions. ResultsIn total, 12 studies were included (Australia, Brazil, Denmark, France, Germany, Ireland, Israel, UK, USA) comprising a total population of 53,805,690. Eleven studies reported prevalence. The pooled proportion of individuals in the general population with HS was 0.36% (95% CI 0.21 - 0.56). Self-reported HS gave a higher prevalence estimate than clinician-diagnosed HS. HS is more prevalent in women. Average annual incidence of HS was 28.5 cases/100,000 (95% CI 26.8 - 30.1). ConclusionsWe estimated the global prevalence of HS to be 0.36% with 3:2 female predominance and average annual incidence to be 28.5 cases/100,000.

9: Deep neural frameworks improve the accuracy of general practitioners in the classification of pigmented skin lesions
more details view paper

Posted 08 May 2020

Deep neural frameworks improve the accuracy of general practitioners in the classification of pigmented skin lesions
946 downloads medRxiv dermatology

Maximiliano Lucius, Jorge De All, Jose Antonio De All, Martin Belvisi, Luciana Radizza, Marisa Lanfranconi, Victoria Lorenzatti, Carlos Maria Galmarini

Artificial intelligence can be a key tool in the context of assisting in the diagnosis of dermatological conditions, particularly when performed by general practitioners with limited or no access to high resolution optical equipment. This study evaluates the performance of deep convolutional neural networks (DNNs) in the classification of seven pigmented skin lesions. Additionally, it assesses the improvement ratio in the classification performance when utilized by general practitioners. Open-source skin images were downloaded from the ISIC archive. Different DNNs (n=8) were trained based on a random dataset constituted by 8,015 images. A test set of 2,003 images has been used to assess the classifiers performance at low (300 x 224 RGB) and high (600 x 450 RGB) image resolution and aggregated clinical data (age, sex and lesion localization). We have also organized two different contests to compare the DNNs performance to that of general practitioners by means of unassisted image observation. Both at low and high image resolution, the DNNs framework being trained differentiated dermatological images with appreciable performance. In all cases, accuracy has been improved when adding clinical data to the framework. Finally, the lowest accurate DNN outperformed general practitioners. Physicians accuracy was statistically improved when allowed to use the output of this algorithmic framework as guidance. DNNS are proven to be high performers as skin lesion classifiers. The aim is to include these AI tools in the context of general practitioners whilst improving their diagnosis accuracy in a routine clinical scenario when or where the use of high-resolution equipment is not accessible.

10: Multidrug therapy with terbinafine plus daily fluconazole is more effective than terbinafine alone or terbinafine plus weekly fluconazole in current epidemic of altered dermatophytosis in India: Results of a randomized pragmatic trial
more details view paper

Posted 22 Aug 2019

Multidrug therapy with terbinafine plus daily fluconazole is more effective than terbinafine alone or terbinafine plus weekly fluconazole in current epidemic of altered dermatophytosis in India: Results of a randomized pragmatic trial
943 downloads medRxiv dermatology

Sanjay Singh, Bandana Jha, Prakriti Shukla, Vinayak N Anchan

BackgroundTreatment responsiveness of tinea has decreased considerably in recent past in India. We tested effectiveness of oral terbinafine daily plus fluconazole weekly (TFw) and terbinafine daily plus fluconazole daily (TFd) versus oral terbinafine daily (T) in tinea corporis, tinea cruris and tinea faciei in a pragmatic randomized open trial. MethodsOne hundred and seventeen microscopy confirmed patients were allocated to T (6 mg/kg/day), TFw (terbinafine 6 mg/kg/day+fluconazole 12 mg/kg once weekly), or TFd (terbinafine 6 mg/kg/day+fluconazole 6 mg/kg/day) groups by concealed randomization and treated for 8 weeks or cure. Each group included 39 patients. ResultsAt 4 weeks, 9 (23.1%), 8 (20.5%) and 14 (35.9%) patients were cured in T, TFw and TFd groups, respectively (P=0.279). At 8 weeks, number of patients cured was as follows: T 13 (33.3%), TFw 18 (46.2%) and TFd 25 (64.1%). TFd was more effective than T (P=0.012), other comparisons were not significantly different. However, effect size as calculated by number needed to treat (NNT) (versus terbinafine) was 8 for TFw and 4 for TFd. Relapse rates one month after cure were similar in all groups (P=0.664). ConclusionsIn view of cure rates and NNT, terbinafine plus daily fluconazole is more effective than terbinafine alone or terbinafine plus weekly fluconazole in current epidemic of altered dermatophytosis in India. One Sentence SummaryTerbinafine plus daily fluconazole is more effective than terbinafine alone or terbinafine plus weekly fluconazole in current epidemic of altered dermatophytosis in India.

11: TzanckNet: A convolutional neural network to identify cells in the cytology of erosive-vesiculobullous diseases
more details view paper

Posted 23 Jun 2020

TzanckNet: A convolutional neural network to identify cells in the cytology of erosive-vesiculobullous diseases
897 downloads medRxiv dermatology

Mehmet Alican Noyan, Murat Durdu, Ali Haydar Eskiocak

Tzanck smear test is a low-cost, rapid, and reliable tool which can be used for the diagnosis of many erosive-vesiculobullous, tumoral, and granulomatous diseases. Currently its use is limited mainly due to lack of experience in interpretation of the smears. We developed a deep learning model, TzanckNet, that can identify cells in Tzanck smear test findings. TzanckNet was trained on a retrospective development dataset of 2260 Tzanck smear images collected between December 2006 - December 2019. The finalized model was evaluated using a prospective validation dataset of 359 Tzanck smear images collected from 15 patients during January 2020. It is designed to recognize six cell types (acantholytic cells, eosinophils, hypha, multinucleated giant cells, normal keratinocytes, and tadpole cells). For 359 images and 6 cell types, TzanckNet made 2154 predictions. The accuracy was 94.3 % (95% CI 93.4 to 95.3), the sensitivity was 83.7 % (95% CI 80.3 to 87.0) and the specificity was 97.3 % (95% CI 96.5 to 98.1). The area under the receiver operating characteristic curve was 0.974. Our results show that TzanckNet has the potential to lower the experience barrier needed to use this test, broadening its user base, and hence improving patient well-being.

12: DermoExpert: Skin lesion classification using a hybrid convolutional neural network through segmentation, transfer learning, and augmentation
more details view paper

Posted 05 Feb 2021

DermoExpert: Skin lesion classification using a hybrid convolutional neural network through segmentation, transfer learning, and augmentation
864 downloads medRxiv dermatology

Md. Kamrul Hasan, Md. Toufick E Elahi, Md. Ashraful Alam, Md. Tasnim Jawad

Background and ObjectiveAlthough automated Skin Lesion Classification (SLC) is a crucial integral step in computeraided diagnosis, it remains a challenging task due to inconsistency in texture, color, indistinguishable boundaries, and shapes. MethodsIn this article, we propose an automatic and robust framework for the dermoscopic SLC named Dermoscopic Expert (DermoExpert). The DermoExpert consists of a preprocessing, a hybrid Convolutional Neural Network (hybrid-CNN), and transfer learning. The proposed hybrid-CNN classifier consists of three distinct feature extractors, with the same input images, which are fused to achieve better-depth feature maps of the corresponding lesion. Those distinct and fused feature maps are classified using the different fully connected layers, which are then ensembled to get a final prediction probability. In the preprocessing, we use lesion segmentation, augmentation, and class rebalancing. For boosting the lesion recognition, we have also employed geometric and intensity-based augmentation as well as the class rebalancing by penalizing the loss of the majority class and adding extra images to the minority classes. Additionally, we leverage the knowledge from a pre-trained model, also known as transfer learning, to build a generic classifier, although small datasets are being used. In the end, we design and implement a web application by deploying the weights of our DermoExpert for automatic lesion recognition. ResultsWe evaluate our DermoExpert on the ISIC-2016, ISIC-2017, and ISIC-2018 datasets, where our DermoExpert has achieved the area under the receiver operating characteristic curve (AUC) of 0.96, 0.95, and 0.97, respectively. The experimental results outperform the recent state-of-the-art by a margin of 10.0 % and 2.0 % respectively for ISIC-2016 and ISIC-2017 datasets in terms of AUC. The DermoExpert also outperforms, in concerning a balanced accuracy, by a margin of 3.0 % for ISIC-2018 dataset. ConclusionSince our framework can provide better-classification on three different test datasets, even with limited training data, it can lead to better-recognition of melanoma to aid dermatologists. Our source code, and segmented masks, for ISIC-2018 dataset, will be made publicly available for the research community for further improvements.

13: Machine learning applied to atopic dermatitis transcriptome reveals distinct therapy-dependent modification of the keratinocyte immunophenotype
more details view paper

Posted 19 Dec 2019

Machine learning applied to atopic dermatitis transcriptome reveals distinct therapy-dependent modification of the keratinocyte immunophenotype
852 downloads medRxiv dermatology

K. Clayton, A. Vallejo, S. Sirvent, J. Davies, G. Porter, F. Lim, M.R. Ardern-Jones, M.E. Polak

BackgroundAtopic dermatitis (AD) arises from a complex interaction between an impaired epidermal barrier, environmental exposures, and the infiltration of Th1/Th2/Th17/Th22 T cells. Transcriptomic analysis has advanced understanding of gene expression in cells and tissues. However, molecular quantitation of cytokine transcripts does not predict the importance of a specific pathway in AD or cellular responses to different inflammatory stimuli. ObjectiveTo understand changes in keratinocyte transcriptomic programmes in human cutaneous disease during development of inflammation and in response to treatment. MethodsWe performed in silico deconvolution of the whole-skin transcriptome. Using co-expression clustering and machine learning tools, we resolved the gene expression of bulk skin (n=7 datasets, n=406 samples), firstly, into unsupervised keratinocyte immune response phenotypes and, secondly, into 19 cutaneous cell signatures of purified populations from publicly available datasets. ResultsWe identify three unique transcriptomic programmes in keratinocytes, KC1, KC2, KC17, characteristic to immune signalling from disease-associated helper T cells. We cross-validate those signatures across different skin inflammatory conditions and disease stages and demonstrate that the keratinocyte response during treatment is therapy dependent. Broad spectrum treatment with ciclosporin ameliorated the KC17 response in AD lesions to a non-lesional immunophenotype, without altering KC2. Conversely, the specific anti-Th2 therapy, dupilumab, reversed the KC2 immunophenotype. ConclusionOur analysis of transcriptomic signatures in cutaneous disease biopsies reveals the complexity of keratinocyte programming in skin inflammation and suggests that the perturbation of a single axis of immune signal alone may be insufficient to resolve keratinocyte immunophenotype abnormalities.

14: Skin Lesion Classification Using Convolutional Neural Network for Melanoma Recognition
more details view paper

Posted 26 Nov 2020

Skin Lesion Classification Using Convolutional Neural Network for Melanoma Recognition
819 downloads medRxiv dermatology

Aishwariya Dutta, Md. Kamrul Hasan, Mohiuddin Ahmad

Skin cancer, also known as melanoma, is generally diagnosed visually from the dermoscopic images, which is a tedious and time-consuming task for the dermatologist. Such a visual assessment, via the naked eye for skin cancers, is challenging and arduous due to different artifacts such as low contrast, various noise, presence of hair, fiber, and air bubbles, etc. This article proposes a robust and automatic framework for the Skin Lesion Classification (SLC), where we have integrated image augmentation, Deep Convolutional Neural Network (DCNN), and transfer learning. The proposed framework was trained and tested on the publicly available IEEE International Symposium on Biomedical Imaging (ISBI)-2017 dataset. The obtained average area under the receiver operating characteristic curve (AUC), recall, precision, and F1-score are respectively 0.87, 0.73, 0.76, and 0.74 for the SLC. Our experimental studies for lesion classification demonstrate that the proposed approach can successfully distinguish skin cancer with a high degree of accuracy, which has the capability of skin lesion identification for melanoma recognition.

15: Oral Collagen for the treatment of Dermal Atrophy: A systematic review of human trials
more details view paper

Posted 19 Jul 2020

Oral Collagen for the treatment of Dermal Atrophy: A systematic review of human trials
793 downloads medRxiv dermatology

Rhydian P Howell-Morris

BACKGROUND Dermal atrophy (DA) or skin "thinning" can cause a substantial impact on quality of life and, due to barrier function damage, further health problems including cutaneous infection, skin tears and lacerations from minor trauma, impaired wound healing and chronic dermal inflammation. Some dietary products are targeted at therapeutic and functional treatments for skin ageing (of which mild DA is a component); however, while dietary collagen is amongst the most popular, particularly in the form of collagen peptides (CPs), in contrast to reviews for both over-the-counter and under prescription topical treatments for DA (e.g. Tretinoin), there is no reviewed literature of human trials testing the efficacy of orally administered collagen treatments applicable to DA; hence this review. OBJECTIVE To review the literature and assess available randomised-controlled trials (RCTs) testing the efficacy of orally administered collagen treatments for any skin properties that relate to the pathophysiology of DA and suggest their potential for medical and general public use in treating DA. EVIDENCE REVIEW METHOD A PubMed search was conducted using "(collagen) AND (supplementation OR treatment) AND (skin OR dermis)", after which titles and abstracts were screened to decide if they matched the inclusion criteria for review. Results were collected up to 1st of August 2019 and no lower limit on the year of publication was set. MAIN RESULTS Five studies with a total of 430 participants were included for review, with participants aged 24-70. Four out of the five studies used female only participants. The five studies used orally administered CPs, with dosage ranging from 570 mg/d to 10 g/d, running from 8 weeks to 6 months and assessed a range of skin properties relevant to DA including dermal thickness, epidermal thickness, dermal density, dermal collagen content, dermal collagen density and dermal elasticity. One of the studies combined CPs with several antioxidant ingredients to form the treatment and the remaining 4 studies used CPs as the only active ingredient. Methods to control for potential confounders were implemented in most studies including limiting exposure to sun, implementing a pre-treatment period of 1 week or more that controlled the use of cosmetics and intake of certain medications, micronutrient supplements and nutraceuticals with those restrictions continuing for the duration of the study. Given the heterogeneity of outcome measures across studies, quantitative analysis of results was not possible. In summary, the study with the antioxidant combined supplement showed a significant improvement in dermal thickness; two of the studies showed improvement in dermal collagen or pro-collagen content; three of the studies showed improvement in dermal elasticity; three studies showed improvement in dermal density or dermal collagen density; and lastly, no human study was found with the stated objective of assessing CPs effect specifically on DA. CONCLUSION Although definitive mechanistic cause-effect conclusions could not be drawn from the existing studies, they are supportive of beneficial effects of oral CP intake for treating characteristics of dermal atrophy. Further elucidation of the exact mode(s) of action that the CP intake has on improving dermal thickness, dermal density, and other skin biomarkers is necessary, with larger studies including more finely divided experimental and dose-response groups. In conclusion, rigorousness of the trials must be improved to establish a cause-effect relationship between the CP intake and the beneficial effects for the skin atrophy, however potential has been demonstrated.

16: An acute bleomycin inflammatory and fibrotic mouse model of morphea is dependent upon CXCL9 and CXCR3
more details view paper

Posted 28 Jun 2019

An acute bleomycin inflammatory and fibrotic mouse model of morphea is dependent upon CXCL9 and CXCR3
790 downloads medRxiv dermatology

Jillian M. Richmond, Dhrumil Patel, Tomoya Watanabe, Colton J. Garelli, Madhuri Garg, Karen Dresser, April Deng, Carol A. Feghali-Bostwick, John E. Harris, Heidi Jacobe

Morphea, or localized scleroderma, is characterized by an inflammatory phase followed by cutaneous fibrosis, which may lead to disfigurement and/or disability. Previous work from our group showed that the CXCR3 ligands CXCL9 and CXCL10 are highly upregulated in lesional skin of morphea patients. Here, we used an acute inflammatory and fibrotic bleomycin mouse model of morphea to examine the role of the CXCR3 chemokine axis in pathogenesis. We first characterized which cells produce the CXCR3 ligands in the skin using the Reporter of Expression of CXCR3 ligands mouse (REX3). We found that fibroblasts contribute the bulk of CXCL9 and CXCL10, whereas endothelial cells are key dual chemokine producers. Macrophages, which have high MFI of chemokine expression, upregulated CXCL9 production over time, fibroblasts CXCL10 production, and T cells dual chemokine expression. To determine whether bleomycin treatment could directly induce expression of these chemokines, we treated cultured REX3 mouse dermis monolayers in vitro with bleomycin or IFN{gamma} with TNF and found that bleomycin could induce low amounts of CXCL9 directly in fibroblasts, whereas the cytokines were required for optimal CXCL9 and CXCL10 production. To determine whether these chemokines are mechanistically involved in pathogenesis, we induced fibrosis in CXCL9, CXCL10, or CXCR3 deficient mice and found that fibrosis is dependent on CXCL9 and CXCR3. Addition of recombinant CXCL9, but not CXCL10, to cultured mouse fibroblasts induces collagen 1a1 mRNA expression, indicating the chemokine itself can contribute to fibrosis. Taken together, our studies provide evidence that acute intradermal bleomycin administration in mice can model inflammatory morphea, and that CXCL9 and its receptor CXCR3 are mechanistically involved in pathogenesis. One Sentence SummaryCXCL9 drives acute morphea pathogenesis in mice.

17: CHILDHOOD VITILIGO: A RETROSPECTIVE CLINICO-EPIDEMIOLOGICAL STUDY
more details view paper

Posted 18 Sep 2020

CHILDHOOD VITILIGO: A RETROSPECTIVE CLINICO-EPIDEMIOLOGICAL STUDY
774 downloads medRxiv dermatology

Ahmed Abdul-aziz Ahmed, Hayder Saad Ahmed, Mustafa Hameed Mohammed, Mohammed Shanshal

Background: Vitiligo is an acquired depigmentary disorder of the skin, mucous membrane and hair follicle resulting from selective destruction of melanocytes. Aims of Study: Identify the clinico-epidemiological characteristics of childhood vitiligo. Patients and Methods: A retrospective study carried out at the dermato-venereology clinic of Salah Al-Din Hospital. A total of 120 vitiligo patients, all younger than 17 years old, were enrolled. Results: Among included patients, (40%) were male and (60%) were female (M:F=2:3). The mean age of onset was (11.5 SD 6.4 years) with (60.8%) of patients were (11-17) years old, (25%) were (6-11) years and (14.2%) were (0-5) years old. Majority of patients were from urban area (87.5%). Generalized types of vitiligo account for (56.7%) besides (22.5%), (17.5%) and (3.3%) represented focal, acrafacial and segmental vitiligo, respectively. Only (8.3%) have nail changes, presented as longitudinal ridging followed by leukonychia. Family history was positive in (37.5%) of vitiligo patients. Treatment used for vitiligo were topical corticosteroids (92.5%), topical calcineurin inhibitors (55%), NB-UVB (84.2%), and systemic steroids (30.8%). Conclusions: Majority of childhood vitiligo develops after puberty and predominantly affects female. Generalized vitiligo is the most frequent type. Atopic dermatitis is the most common associated disease.

18: Retrospective Assessment of Deep Neural Networks for Skin Tumor Diagnosis
more details view paper

Posted 15 Dec 2019

Retrospective Assessment of Deep Neural Networks for Skin Tumor Diagnosis
767 downloads medRxiv dermatology

Seung Seog Han, Ik Jun Moon, Jung-Im Na, Myoung Shin Kim, Gyeong Hun Park, Seong Hwan Kim, Kiwon Kim, Ju Hee Lee, Sung Eun Chang

BACKGROUND The aim of this study was to validate the performance of algorithm (http://rcnn.modelderm.com) for the diagnosis of benign and malignant skin tumors. METHODS With external validation dataset (43 disorders; 40,331 clinical images from 10,426 patients; January 1, 2008 - March 31, 2019), we compared the prediction of algorithm with the clinical diagnosis of 65 attending physicians at the time of biopsy request. RESULTS For binary-task classification of determining malignancy, the AUC of the algorithm was 0.863(95% CI 0.852-0.875) with unprocessed clinical photographs. The sensitivity / specificity of the algorithm at the predefined high-sensitivity and high-specificity threshold were 79.1%(76.9-81.4) / 76.9%(76.1-77.8) and 62.7%(59.9-65.5) / 90.0%(89.4-90.6), respectively. The sensitivity/specificity calculated by the clinical diagnosis of attending physicians were 88.1% / 83.8%(Top-3) and 70.2% / 95.6%(Top-1), which were superior to those of algorithm. For multi-task classification, the mean Top-1,2,3 accuracies of the algorithm were 42.6%, 56.1%, 61.9%, and those of clinical diagnosis were 65.4%, 73.9%, 74.7%, respectively. In the reader test with images from 30-patients batches, the sensitivity / specificity of the algorithm at the predefined threshold were 66.9% / 87.4%. The sensitivity / specificity derived from the first diagnosis of 44 the participants were 65.8% / 85.7%, which were comparable with those of the algorithm (Wilcoxon signed-rank test; P=0.61 / 0.097). CONCLUSIONS Our algorithm could diagnose skin tumors at dermatologist-level when diagnosis was made solely with photographs, demonstrating its potential as a mass screening tool in telemedicine setting. However, due to limited data relevancy, the performance was inferior to that of actual medical examination. Clinical information should be integrated with imaging information to achieve more accurate predictions.

19: Dysregulation of tryptophan catabolism at the host-skin microbiota interface in Hidradenitis Suppurativa
more details view paper

Posted 31 Aug 2020

Dysregulation of tryptophan catabolism at the host-skin microbiota interface in Hidradenitis Suppurativa
761 downloads medRxiv dermatology

Laure Guenin-Mace, Jean-David Morel, Jean-Marc Doisne, Angele Schiavo, Lysiane Boulet, Veronique Mayau, Pedro Goncalves, Sabine Duchatelet, Alain Hovnanian, Vincent Bondet, Darragh Duffy, Marie-Noƫlle Ungeheuer, Maia Delage, Aude Nassif, James P. Di Santo, Caroline Demangel

Hidradenitis Suppurativa (HS) is a chronic skin disorder of unknown etiology that manifests as recurrent, painful lesions. Cutaneous dysbiosis and unresolved inflammation are hallmarks of active HS, but their origin and interplay remain unclear. Our metabolomic profiling of HS skin revealed an abnormal induction of the kynurenine pathway (KP) of tryptophan catabolism in dermal fibroblasts correlating with the release of KP-inducing cytokines by inflammatory cell infiltrates. Notably, over-activation of the KP in lesional skin was associated with local and systemic depletion in tryptophan. Yet the skin microbiota normally degrades host tryptophan into indoles regulating tissue inflammation via engagement of the Aryl Hydrocarbon Receptor (AHR). In HS skin lesions, we detected contextual defects in AHR activation coinciding with impaired production of bacteria-derived AHR agonists and decreased incidence of AHR ligand-producing bacteria in the resident flora. Dysregulation of tryptophan catabolism at the skin-microbiota interface thus provides a mechanism linking the immunological and microbiological features of HS lesions. In addition to revealing metabolic alterations in HS patients, our study suggests that correcting AHR signaling would help restore immune homeostasis in HS skin.

20: Causal analysis shows evidence of atopic dermatitis leading to an increase in vitamin D levels
more details view paper

Posted 23 Apr 2020

Causal analysis shows evidence of atopic dermatitis leading to an increase in vitamin D levels
744 downloads medRxiv dermatology

Daniel R Drodge, Ashley Budu-Aggrey, Lavinia Paternoster

Atopic dermatitis (AD) patients have been observed to have lower vitamin D levels. Previous studies have found little evidence that vitamin D levels causally influence the risk of AD, but the reverse direction has not yet been investigated. Here we used Mendelian Randomization to assess the causal relationship between AD and serum vitamin D levels, using genetic data from the most recent GWA studies of vitamin D and AD. There was little evidence for vitamin D levels causally influencing AD risk (odds per standard deviations increase in log-transformed vitamin D levels =1.233, 95% CI 0.927 to 1.639, P-value =0.150). However, genetic liability for AD raises serum vitamin D levels by 0.043 (95% CI 0.017 to 0.069) standard deviations per doubling of odds of disease (P-value =0.001). The AD-associated filaggrin (FLG) mutation R501X appears to show a particularly strong relationship with vitamin D. However, the relationship between AD and vitamin D holds when R501X is omitted (0.018, 95% CI 0.004 to 0.031, P-value =0.008). We found evidence that AD is causally associated with an increase in serum vitamin D levels. Whilst the AD-associated FLG gene has a particularly strong relationship with vitamin D, other AD SNPs show a consistent direction of effect, suggesting that AD more generally influences serum vitamin D levels.

Previous page 1 2 3 4 Next page

PanLingua

News