The effect of chemical constitution on polyisoprene dynamics.

Polyisoprene (PI) melts have been studied, with most reports focusing on systems with high 1,4-cis content. In contrast, 1,4-trans PI homopolymers or random copolymers have seldom been examined, despite a handful of investigations suggesting a distinct dynamic behavior. Herein, we employ all-atom simulations to investigate the effect of chemical architecture on the dynamics of cis and trans-PI homopolymers, as well as copolymers. We examine the thermodynamic, conformational, and structural properties of the polymers and validate the performance of the models. We probe chain dynamics, revealing that cis-PI presents accelerated translation and reorientation modes relative to trans as recorded by the mean square displacement of the chain center-of-mass as well as by the characteristic times of the lower modes in a Rouse analysis. Interestingly, progressing to higher modes, we observe a reversal with trans units exhibiting faster dynamics. This was further confirmed by calculations of local carbon-hydrogen vector reorientation dynamics, which offer a microscopic view of segmental mobility. To obtain insight into the simulation trajectories, we evaluate the intermediate incoherent scattering function that supports a temperature-dependent crossover in relative mobility that extends over separations beyond the Kuhn-length level. Finally, we analyzed the role of non-Gaussian displacements, which demonstrate that cis-PI exhibits increased heterogeneity in dynamics over short-timescales in contrast to trans-PI, where deviations persist over times extending to terminal dynamics. Our all-atom simulations provide a fundamental understanding of PI dynamics and the impact of microstructure while providing important data for the design and optimization of PI-based materials.

Bleach baths for atopic dermatitis: A systematic review and meta-analysis including unpublished data, Bayesian interpretation, and GRADE.

BACKGROUND: Bleach bathing is frequently recommended to treat atopic dermatitis (AD), but its efficacy and safety are uncertain. OBJECTIVE: To systematically synthesize randomized controlled trials (RCTs) addressing bleach baths for AD. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and GREAT from inception to December 29, 2021, for RCTs assigning patients with AD to bleach vs no bleach baths. Paired reviewers independently and in duplicate screened records, extracted data, and assessed risk of bias (Cochrane version 2) and GRADE quality of evidence. We obtained unpublished data, harmonized individual patient data and did Frequentist and Bayesian random-effects meta-analyses. RESULTS: There were 10 RCTs that enrolled 307 participants (median of mean age 7.2 years, Eczema Area Severity Index baseline mean of means 27.57 [median SD, 10.74]) for a median of 6 weeks (range, 4-10). We confirmed that other trials registered globally were terminated. Bleach baths probably improve AD severity (22% vs 32% improved Eczema Area Severity Index by 50% [ratio of means 0.78, 95% credible interval 0.59-0.99]; moderate certainty) and may slightly reduce skin Staphylococcal aureus colonization (risk ratio, 0.89 [95% confidence interval, 0.73-1.09]; low certainty). Adverse events, mostly dry skin and irritation, along with itch, patient-reported disease severity, sleep quality, quality of life, and risk of AD flares were not clearly different between groups and of low to very low certainty. CONCLUSION: In patients with moderate-to-severe AD, bleach baths probably improve clinician-reported severity by a relative 22%. One in 10 will likely improve severity by 50%. Changes in other patient-important outcomes are uncertain. These findings support optimal eczema care and the need for additional large clinical trials. TRIAL REGISTRATION: PROSPERO Identifier: CRD42021238486.

Bacteriophages: An Alternative to Combat Antibiotic Resistance?

BACKGROUND: Antibiotic resistance has become one of the largest pitfalls of modern medicine, and this has fueled the search for a safe and effective alternative. Of these alternatives, bacteriophage (phage) therapy has emerged as a potential option since it is capable of destroying pathogenic bacteria, without disrupting commensal bacterial populations. Although numerous studies have shown its efficacy in various conditions such as dysentery, sepsis, and meningitis, very little research has focused on its prospective usage to treat dermatological conditions. This review discusses the emerging phage therapy studies surrounding infections caused by Cutibacterium acnes (C. acnes), Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Klebsiella pneumoniae (K. pneumoniae). Phage therapy shows major potential for future usage in the field of dermatology, yet further research must be performed to assure safety and efficacy in humans. J Drugs Dermatol. 2022;21(12):1311-1315. doi:10.36849/JDD.6638.

Lasers, Birthmarks, and Sturge-Weber Syndrome: A Pilot Survey.

BACKGROUND AND OBJECTIVES: There is limited or no data on the experience of patients with Sturge-Weber Syndrome (SWS) and/or their parents who seek out laser treatments for their port-wine birthmark (PWB). Our study aimed to develop a survey to understand patient perspectives on laser therapy and subsequent behaviors while focusing on three elements of the health belief model: perceived susceptibility, perceived benefits, and perceived barriers. STUDY DESIGN/MATERIALS AND METHODS: A 31 item survey was developed and sent to 650 members of the Sturge-Weber Foundation. The survey included questions regarding four domains: demographics, disease severity, laser experience, and perceptions and behaviors. Logistic regression models and bivariate analyses were conducted to analyze the results. RESULTS: Among the 123 respondents, earlier initiation of laser treatments was associated with greater birthmark satisfaction. Overall satisfaction increased up to 20 treatments and then leveled off. Color satisfaction increased up to 100 laser treatments; however, the flatness of the PWB was not associated with the number of laser treatments. The perceived benefits of lasers were not associated with the number of lifetime treatments or with spending. However, the perceived susceptibility was associated with greater spending on travel and medical expenses. CONCLUSION: The results of our survey provide insight into SWS patient experiences, beliefs, and behaviors regarding laser therapy. Further exploration of these variables may allow for the improvement of the care experience. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

DMSO: an aid to combat pain and pruritus.

Dimethyl sulfoxide (DMSO) is a highly reactive by-product of paper production in the form of an odorless, colorless liquid that has been studied since the 1860s. Initially it was utilized as a solvent, but more recently it is being investigated for therapeutic applications. Owing to its versatility, the use of DMSO has been proposed in many different medical fields for a variety of applications, with possibly the widest use being in the field of dermatology. The clinical interest in the use of DMSO for dermatology conditions stems from this solution's efficacy as a vehicle to deliver pharmacological agents across the stratum corneum and its ability to penetrate biological membranes. Currently there is only one FDA approval for the use of DMSO, and it is not in the dermatologic field but rather for interstitial cystitis. Outside of the FDA scope of usage, DMSO is used frequently to treat osteoarthritis in humans and animals, as well as other chronic pain conditions. This suggests the possible utility of DMSO being applicable to other inflammatory conditions such as pruritus. Further research is necessary to explore the promising utilization opportunities of DMSO in dermatology.

Backmapping coarse-grained macromolecules: An efficient and versatile machine learning approach.

Multiscale modeling of polymers exchanges information between coarse and fine representations of molecules to capture material properties over a wide range of spatial and temporal scales. Restoring details at a finer scale requires us to generate information following embedded physics and statistics of the models at two different levels of description. Techniques designed to address this persistent challenge balance among accuracy, efficiency, and general applicability. In this work, we present an image-based approach for structural backmapping from coarse-grained to atomistic models with cis-1,4 polyisoprene melts as an illustrative example. Through machine learning, we train conditional generative adversarial networks on the correspondence between configurations at the levels considered. The trained model is subsequently applied to provide predictions of atomistic structures from the input coarse-grained configurations. The effect of different data representation schemes on training and prediction quality is examined. Our proposed backmapping approach shows remarkable efficiency and transferability over different molecular weights in the melt based on training sets constructed from oligomeric compounds. We anticipate that this versatile backmapping approach can be readily extended to other complex systems to provide high-fidelity initial configurations with minimal human intervention.

"Live Sun Smart!" Testing the effectiveness of a sun safety program for middle schoolers.

BACKGROUND: Skin cancer is a well-recognized public health issue, and primary prevention is the most effective strategy for reducing skin cancer risk. The current recommendations are that behavioral counseling for sun safety measures is most beneficial and effective for children and adolescents and that targeting this population at primary and middle schools is the ideal intervention strategy to increase sun-protective behaviors and reduce UV exposure, sunburn incidence, and formation of new moles. Numerous studies on the effectiveness of school-based sun safety interventions among elementary and middle school students have shown an increase in sun safety knowledge, attitudes, and behaviors following the intervention. OBJECTIVE: To conduct a pilot feasibility study of "Live Sun Smart!," (LSS) a school-based, multicomponent, interactive sun safety presentation, at changing sun safety knowledge, attitudes, and behaviors among middle school students. METHODS: A non-randomized, single-group pretest-posttest interventional pilot study of the LSS program among children enrolled in grade 6. RESULTS: After exposure to LSS, participants were more likely to give correct answers to knowledge-based sun safety questions and to report negative attitudes toward tanning. Minimal and not significant changes were found in self-reported sun safety behaviors, though students did report an intention to change behaviors following the intervention. Participants were satisfied with the program and believed it increased their sun safety knowledge. CONCLUSION: Live Sun Smart! appears to be an effective school-based, multicomponent sun safety program for improving sun safety knowledge and attitudes toward tanning among middle school students in this initial test of it. The strengths and weaknesses of this pilot study have implications for future research.

Structural racism and its influence on the severity of atopic dermatitis in African American children.

BACKGROUND/OBJECTIVES: Atopic dermatitis (AD) is the most common skin disease of childhood and is often more severe in African American than white children. The reason for this disparity is unknown, but recent research indicates that it may be due to a combination of environmental and genetic factors. The objective of this article was to explore the relationship between measures of structural racism and residential segregation within pediatric AD. METHODS: An in-office, online survey consisting of 58 questions spanning 5 domains (demographics, in-home crowding, community crowding, air quality, and litter) was administered to a convenience sample of 201 pediatric AD patients (age 0-18 years). Survey data were geocoded and linked to a measure of structural racism (ie, residential segregation). RESULTS: African American children were more likely to live in rented homes, be in lower income families, have caregivers with lower educational attainment, and be exposed to tobacco smoke. The same factors that were associated with worse AD severity in this study were also found in published literature, emphasizing the role of social determinants of health and racial differences in AD severity. Additionally, this study found that living in highly segregated communities was more likely to be associated with severe AD in African American children. CONCLUSIONS: Consistent with reported literature, socioeconomic status, race, and the physical environment appear to affect AD severity. This investigation adds structural racism as an important community characteristic that likely has significant effects on AD severity for African American Children.

Idiopathic, Refractory Sweet's Syndrome Associated with Common Variable Immunodeficiency: a Case Report and Literature Review.

PURPOSE OF REVIEW: Sweet's syndrome (SS) is classically considered a hypersensitivity reaction often associated with autoimmune disorders and malignancy. SS has also been increasingly reported to occur with immunodeficiencies. We present a case of treatment-refractory, systemic SS as the initial manifestation in a young child with common variable immunodeficiency (CVID). We also review current literature about SS and concurrent immunodeficiencies and autoimmunity in CVID patients. RECENT FINDINGS: Few case reports exist regarding the co-occurrence of Sweet's syndrome and primary immunodeficiencies. SS is characterized by a pro-inflammatory state with a neutrophil predominance resulting in a spectrum of clinical manifestations. CVID is a multifactorial antibody deficiency that can be associated with autoimmunity, which some studies have proposed to be secondary to altered CD21 expression. SS occurring in patients with CVID has been infrequently reported, and one case study demonstrated improvement of Sweet's associated skin lesions with immunoglobulin replacement. In our case, the patient had multi-system SS refractory to multiple immunomodulatory therapies. To our knowledge, this is the first report of the effective and safe use of intravenous tocilizumab and oral lenalidomide to treat SS in a child with CVID. Immunoglobulin replacement reduced the frequency of infections and may have contributed to the opportunity to wean the immunosuppressive therapies for Sweet's syndrome. Sweet's syndrome as an initial manifestation of co-occurring immunodeficiencies is rare, and providers need a high index of suspicion. In addition, treatment of SS associated with an immunodeficiency can be a challenge. Treatment with immunoglobulin replacement reduces the frequency of infections, and in some patients with concurrent SS may improve skin lesions and reduce the need for immunomodulator therapy. Further study is necessary to better understand the pathogenesis of CVID in patients with SS and to identify possible biomarkers that predict who with SS are at risk for developing hypogammaglobulinemia.

North American clinical management guidelines for hidradenitis suppurativa: A publication from the United States and Canadian Hidradenitis Suppurativa Foundations: Part II: Topical, intralesional, and systemic medical management.

Hidradenitis suppurativa is a severe and debilitating dermatologic disease. Clinical management is challenging and consists of both medical and surgical approaches, which must often be combined for best outcomes. Therapeutic approaches have evolved rapidly in the last decade and include the use of topical therapies, systemic antibiotics, hormonal therapies, and a wide range of immunomodulating medications. An evidence-based guideline is presented to support health care practitioners as they select optimal medical management strategies and is reviewed in this second part of the management guidelines. A therapeutic algorithm informed by the evidence available at the time of the review is provided.

North American clinical management guidelines for hidradenitis suppurativa: A publication from the United States and Canadian Hidradenitis Suppurativa Foundations: Part I: Diagnosis, evaluation, and the use of complementary and procedural management.

Hidradenitis suppurativa is a chronic inflammatory disorder affecting hair follicles, with profoundly negative impact on patient quality of life. Evidence informing ideal evaluation and management of patients with hidradenitis suppurativa is still sparse in many areas, but it has grown substantially in the last decade. Part I of this evidence-based guideline is presented to support health care practitioners as they select optimal management strategies, including diagnostic testing, comorbidity screening, and both complementary and procedural treatment options. Recommendations and evidence grading based on the evidence available at the time of the review are provided.

Solitary plaque on the leg of a child: A report of two cases and a brief review of acral pseudolymphomatous angiokeratoma of children and unilesional mycosis fungoides.

Acral pseudolymphomatous angiokeratoma of children (APACHE) and unilesional mycosis fungoides (MF) are two rare dermatoses in the pediatric population which may have overlapping clinical and histopathologic features, making differentiation between these two diagnoses difficult. We present two similar cases of a solitary plaque on the thigh of a child, one representing APACHE and the other representing unilesional MF with granulomatous features, and we provide a brief overview of the clinical and histopathologic features of APACHE and unilesional MF.

Thread epilation: a less traumatic technique for patients undergoing isotretinoin therapy.

Skin fragility is a well-established complication of isotretinoin therapy for severe or resistant acne and presents a challenge to traditional modes of epilation such as waxing. As such, other less traumatic hair removal methods are desired. Herein we present the threading technique as an alternative form of epilation for patients in whom waxing is contraindicated secondary to concerns over skin fragility.

Pediatric periorificial dermatitis: clinical course and treatment outcomes in 222 patients.

BACKGROUND: Periorificial dermatitis (POD) is a rosacea-like papulopustular facial eruption most commonly reported in young adult women. Although POD has been reported in children as young as 6 months of age, there are limited data on the diagnosis and management of POD in pediatric cases. METHODS: All children diagnosed with POD at the Dermatology Clinic at the University of North Carolina at Chapel Hill between June 2002 and March 2014 were included in the current study. Information related to demographics, associated risk factors, treatment prescribed, adverse effects, and response to treatment were obtained from a retrospective analysis of medical records. RESULTS: Of the 222 children identified, 55.4% were female, 62.2% Caucasian, and the average age at presentation to the clinic was 6.6 years. Although the etiology of POD remains uncertain, 29.3% reported a past medical history of atopic dermatitis, 14.9% reported a history of asthma and 58.1% reported a history of steroid use prior to POD onset. Fifty-nine percent were seen at a clinic visit for follow-up at an average of 3.8 months. Treatment often involved combining oral azithromycin with topical metronidazole or sodium sulfacetamide lotion. Of the patients with documented follow-up, 71.8% experienced complete resolution of POD. Recurrence of POD occurred in children dependent on inhaled steroids or nebulizers. Adverse effects were minimally noted, but included pigmentary changes (1.8%), worsening of symptoms (1.8%), gastrointestinal upset (0.9%), irritant dermatitis (0.9%), and xerosis (0.5%). CONCLUSION: This study discusses the clinical diagnosis and management of POD in pediatric cases.

Isotretinoin and vitiligo: can chronic cheilitis cause koebnerization?

Vitiligo after trauma through koebnerization is a widely reported phenomenon. Herein we present a case of vitiligo in an area of chronic cheilitis after isotretinoin treatment.

Wolf's Isotopic Response: Varicella Within a Prior Immunization Reaction Site.

Wolf's isotopic response describes the occurrence of a dermatologic condition at the site of a prior healed unrelated condition. Our report details a case of varicella occurring as a secondary condition at the site of a prior immunization reaction; herpesvirus infection has not been reported as a secondary condition in cases of Wolf's isotopic response before. Current hypotheses favor the involvement of neurohormonal modulation of local immunity in response to various forms of injury as a model for explaining these phenomena.

Metastatic spiradenocarcinoma occurring in an 8-year-old boy.

We recently saw the case of an 8-year-old boy with histologic findings of spiradenocarcinoma. Malignant adnexal tumors in children are exceedingly rare, and cases of spiradenocarcinoma in children are absent in the literature. We report the case of an 8-year-old boy with metastatic spiradenocarcinoma. A biopsy 2 years before his presentation at our institution was interpreted as a benign lesion, but when the lesion regrew, a repeat biopsy was performed that demonstrated ominous findings, prompting a reexcision. This reexcision demonstrated an area with significant necrosis, many mitoses, and cellular pleomorphism apparently arising out of a sharply demarcated, adjacent, lower-grade area. The histologic features of this patient's biopsies were those of spiradenocarcinoma, potentially arising out of a preexisting spiradenoma, a finding that has not been documented previously in this age group. Staging studies demonstrated multiple bilateral pulmonary nodules, which were confirmed using thoracoscopic biopsy to be metastatic disease. His chemotherapy regimen has included several cycles of cisplatin and 5-flourouracil, with ongoing disease progression of pulmonary disease. It has been 16 months since he presented to our institution (>3 years since the appearance of his initial lesion). Imaging studies demonstrate a slowly increasing size and number of pulmonary lesions. The long-term prognosis is guarded.

Genetics of hemangiomas, vascular malformations, and primary lymphedema.

With improved genetic testing and genomic sequencing, abnormalities are increasingly being identified in affected or germline tissues in DNA of patients with vascular tumors, vascular malformations, and lymphedema. Recognition of the genetics of vascular anomalies should help clinicians make more specific diagnoses, anticipate diagnosis-specific morbidities, provide better genetic counseling, and have a better understanding of the pathogenesis of these anomalies. Growing pharmacologic options, including therapies targeted to specific mutations, with obvious parallels to cancer treatment now allow the pediatric hematologist-oncologist to assume a more prominent role in clinical care and research for patients with these diagnoses. We summarize genes and genetic loci that have been associated with vascular anomalies and offer guidelines for patient evaluations.

Multiscale modeling of polyisoprene on graphite.

The local dynamics and the conformational properties of polyisoprene next to a smooth graphite surface constructed by graphene layers are studied by a multiscale methodology. First, fully atomistic molecular dynamics simulations of oligomers next to the surface are performed. Subsequently, Monte Carlo simulations of a systematically derived coarse-grained model generate numerous uncorrelated structures for polymer systems. A new reverse backmapping strategy is presented that reintroduces atomistic detail. Finally, multiple extensive fully atomistic simulations with large systems of long macromolecules are employed to examine local dynamics in proximity to graphite. Polyisoprene repeat units arrange close to a parallel configuration with chains exhibiting a distribution of contact lengths. Efficient Monte Carlo algorithms with the coarse-grain model are capable of sampling these distributions for any molecular weight in quantitative agreement with predictions from atomistic models. Furthermore, molecular dynamics simulations with well-equilibrated systems at all length-scales support an increased dynamic heterogeneity that is emerging from both intermolecular interactions with the flat surface and intramolecular cooperativity. This study provides a detailed comprehensive picture of polyisoprene on a flat surface and consists of an effort to characterize such systems in atomistic detail.

Beetle juice: a guide for the use of cantharidin in the treatment of molluscum contagiosum.

Molluscum contagiosum (MC) is an increasingly common cutaneous viral infection that primarily affects the pediatric population. MC lesions are benign, and most cases resolve within 6-9 months. Nonetheless, many patients and their parents seek active treatment of MC because of local pain, pruritus, embarrassment due to the lesions, or desire to reduce transmission to siblings. Individuals with atopic dermatitis are predisposed to severe and protracted MC, and immunocompromised patients may never clear the infection without treatment. Despite the availability of various therapies, no clear best treatment for MC has emerged. Cantharidin is a commonly used and effective therapy for MC that is generally well tolerated and has high rates of parental satisfaction. In this review, current literature regarding MC is summarized and particular focus is placed on the use of cantharidin for treating MC, including a review of the literature and detailed instructions for its use.