Neonatal brain abscess development following fetal scalp electrode placement: a rare complication

A fetal scalp electrode (FSE) is a frequently used investigation during labor. However, it is an invasive procedure which can lead to complications. Our patient developed a very large brain abscess after initial superficial infection of the skin site due to an FSE. The patient was admitted to the hospital after an asymmetric growth of the skull was noticed with no further signs of clinical illness. MRI showed a very large brain abscess which was aspirated and treated with antibiotics for 10 weeks. A 2-year follow-up showed only a slight developmental delay in gross motor skills. Only once before a similar case has been described at which the patient developed a brain abscess after superficial infection of the scalp following an FSE. In both cases, the brain abscess was noticed due to an asymmetric growth of the skull without any further signs of clinical illness. A brain abscess has a high mortality and morbidity rate, and early diagnosis is vital for the optimal outcome. We therefore recommend to organize an out-patient clinical follow-up for every infant with a superficial infection of the skin site after placement of an FSE.

Cutaneous chemotherapy-induced radiation recall reaction

An 80 year old man with metastatic castrate-resistant prostate cancer was treated with multiple systemic agents but after carboplatin/paclitaxel, developed a morbilliform rash conforming precisely to a skin site of previous palliative radiotherapy, a so-called radiation recall reaction.

Electrodermal Activity: Simultaneous Recordings

Electrodermal activity (EDA) is a sensitive measure of the sympathetic nervous system activity. It is used to describe changes in the skin electrical properties. This chapter aimed to show advantages of simultaneous recordings of EDA parameters at the same skin site over other recordings. The literature databases, Web of Science and Google Scholar, were searched using terms like “electrodermal activity,” “sequential recording,” “simultaneous recording,” “skin conductance,” “skin potential,” and “skin susceptance.” Articles that include sequential and/or simultaneous recording of EDA parameters were analyzed. The chapter presents a description of the oldest and current methods used for recording EDA parameters and an explanation of the newest techniques used in EDA researches. Although sequential recordings are predominant and widely spreading, much effort has been made to simultaneously record skin conductance (SC) and skin potential (SP), and recently researchers realized the capability of simultaneously recording SC, SP, and skin susceptance (SS) at the same skin site. The advantage of simultaneous over the sequence measurements is that the latter must be manually time realigned when measured by different instruments, which means it is time-consuming. Although the simultaneous measurements are used exclusively for research purposes at this stage, this may open horizons in the modern trends of psychophysiology applications in the near future.

Infant Skin Bacterial Communities Vary by Skin Site and Infant Age across Populations in Mexico and the United States

ABSTRACT Daily practices put humans in close contact with the surrounding environment, and differences in these practices have an impact on human physiology, development, and health. There is mounting evidence that the microbiome represents an interface that mediates interactions between the human body and the environment. In particular, the skin microbiome serves as the primary interface with the external environment and aids in host immune function by contributing as the first line of defense against pathogens. Despite these important connections, we have only a basic understanding of how the skin microbiome is first established, or which environmental factors contribute to its development. To this end, this study compared the skin bacterial communities of infants (n = 47) living in four populations in Mexico and the United States that span the socioeconomic gradient, where we predicted that variation in physical and social environments would shape the infant skin microbiome. Results of 16S rRNA bacterial gene sequencing on 119 samples (armpit, hand, and forehead) showed that infant skin bacterial diversity and composition are shaped by population-level factors, including those related to socioeconomic status and household composition, and vary by skin site and infant age. Differences in infant-environment interactions, including with other people, appear to vary across the populations, likely influencing infant microbial exposures and, in turn, the composition of infant skin bacterial communities. These findings suggest that variation in microbial exposures stemming from the local environment in infancy can impact the establishment of the skin microbiome across body sites, with implications for developmental and health outcomes. IMPORTANCE This study contributes to the sparse literature on the infant skin microbiome in general, and the virtually nonexistent literature on the infant skin microbiome in a field setting. While microbiome research often addresses patterns at a national scale, this study addresses the influence of population-level factors, such as maternal socioeconomic status and contact with caregivers, on infant skin bacterial communities. This approach strengthens our understanding of how local variables influence the infant skin microbiome, and paves the way for additional studies to combine biological sample collection with questionnaires to adequately capture how specific behaviors dictate infant microbial exposures. Work in this realm has implications for infant care and health, as well as for investigating how the microbial communities of different body sites develop over time, with applications to specific health outcomes associated with the skin microbiome (e.g., immune system development or atopic dermatitis).

Murine Skin-resident γδT Cells Impair the Immune Response to HSV in Skin

Background: HSV is an important cause of brain infection. Virus entry is often through breeches in the skin. γδT cells play an immunoprotective role in mice after corneal, genital or footpad (subcutaneous) HSV infection. Methods: Here we report that the presence of γδT cells in murine skin is associated with increased severity of herpetic disease, reduced protective cytokine responses and increased viral spread from the skin to the sensory ganglia in the zosteriform model. γδT cell-deficient (TCR δ -/-) mice displayed significantly decreased herpetic lesion severity after flank HSV infection compared to WT C57BL/6 controls at both primary and secondary skin infection sites. Results: Viral titer at the primary skin site was similar to WT mice in γδT cell-deficient mice, but was significantly decreased in the ganglia and secondary skin site. γδT cell-deficient mice showed increased Th1 responses by both T cells and non-T cells at the primary site, and decreased T-cell Th17 responses and immune infiltration at the secondary site. Conclusion: Cytokine responses of epidermal and dermal γδT cells to HSV also differed in WT mice (Th1 in epidermis, and Th17 in the dermis), suggesting a functional dichotomy between these two subsets. Our data suggest that in contrast to other mouse models of HSV infection, skinresident γδT cells promote the pathogenesis of HSV in skin.

Stratum Corneum Biomarkers in Atopic Dermatitis: Biological and Spatial Variability

Background: Atopic dermatitis is a highly heterogeneous skin disease, mainly affecting children. Introduction of biological therapies has urged the development of biomarkers to facilitate personalized therapy. Stratum corneum biomarkers emerged as a promising non-invasive alternative to skin biopsy, yet validation of spatial and biological variability is essential for their application in clinical research. Objective: To assess spatial and biological variability of stratum corneum biomarkers for atopic dermatitis. Methods: Stratum corneum was collected from 17 atopic dermatitis patients by consecutive application of eight adhesive tapes to a lesional skin site and 2 cm and 4 cm from the lesion. Two non-lesional sites at a 2 cm distance from the same lesion were collected to determine biological variability. Filaggrin degradation products (NMF) were determined by liquid chromatography and thirteen cytokines (IL-4, IL-13, IL-18, IL-31, IL-33, CCL17, CCL22, CCL27, CXCL8, IL-1α, IL-RA, IL-18, IL-22) by multiplex immunoassay. Results: Biomarker levels showed gradual changes from lesional to non-lesional skin sites at 2 cm and 4 cm; magnitude and direction of change were biomarker-specific. Intra-subject variability ranged from 17.3% (NMF) to 85.1% (CXCL8). Biomarker levels from two stratum corneum depths were highly correlated; several biomarkers showed significant depth dependence. Conclusion: Stratum corneum enables non-invasive collection of relevant immune and epidermal biomarkers, but biomarker-specific spatial and biological variability emphasizes the importance of standardized procedures for stratum corneum collection.

An enhanced characterization of the human skin microbiome: a new biodiversity of microbial interactions

ABSTRACTThe healthy human skin microbiome is shaped by skin site physiology, individual-specific factors, and is largely stable over time despite significant environmental perturbation. Studies identifying these characteristics used shotgun metagenomic sequencing for high resolution reconstruction of the bacteria, fungi, and viruses in the community. However, these conclusions were drawn from a relatively small proportion of the total sequence reads analyzable by mapping to known reference genomes. ‘Reference-free’ approaches, based on de novo assembly of reads into genome fragments, are also limited in their ability to capture low abundance species, small genomes, and to discriminate between more similar genomes. To account for the large fraction of non-human unmapped reads on the skin—referred to as microbial ‘dark matter’—we used a hybrid de novo and reference-based approach to annotate a metagenomic dataset of 698 healthy human skin samples. This approach reduced the overall proportion of uncharacterized reads from 42% to 17%. With our refined characterization, we revisited assumptions about the skin microbiome, and demonstrated higher biodiversity and lower stability, particularly in dry and moist skin sites. To investigate hypotheses underlying stability, we examined growth dynamics and interspecies interactions in these communities. Surprisingly, even though most skin sites were relatively stable, many dominant skin microbes, including Cutibacterium acnes and staphylococci, were actively growing in the skin, with poor or no relationship between growth rate and relative abundance, suggesting that host selection or interspecies competition may be important factors maintaining community homeostasis. To investigate other mechanisms facilitating adaptation to a specific skin site, we identified Staphylococcus epidermidis genes that are likely involved in stress response and provide mechanisms essential for growth in oily sites. Finally, horizontal gene transfer—another mechanism of competition by which strains may swap antagonistic or virulent coding regions—was relatively limited in healthy skin, but suggested exchange of different metabolic and environmental tolerance pathways. Altogether, our findings underscore the value of a combined reference-based and de novo approach to provide significant new insights into microbial composition, physiology, and interspecies interactions to maintain community homeostasis in the healthy human skin microbiome.

Primary Cutaneous Anaplastic Large-Cell Lymphoma: A Surveillance, Epidemiology, and End Results Database Analysis from 2005-2016

Introduction Primary cutaneous anaplastic large-cell lymphoma (PCALCL) is a rare T-cell lymphoma that presents as a solitary or grouped nodules. It is characterized by anaplastic-appearing cells that are usually ALK negative but have high expression of CD30. There is paucity of epidemiologic data on PCALCL. A prior analysis of the Surveillance, Epidemiology, and End Results (SEER) database by Yu et al. reported only 157 cases from 1973 to 2004. We are presenting an analysis of the patients diagnosed with PCALCL after 2004. Methods We used the SEER database to retrospectively identify patients diagnosed with PCALCL from 2005 to 2016. The database collects data from cancer registries covering approximately 26% of the US population and was used to estimate frequencies and overall incidence rate. Survival was analyzed using the Kaplan-Meier method and log-rank tests were used to compare survival distributions. We assessed the effect of primary skin site (head and neck) and increasing age on survival as they were suggestive of decreased overall survival on multivariate analysis of the 1973-2004 cohort. P < 0.05 was considered statistically significant for all analysis. Results There were 501 cases of PCALCL recorded from 2005 to 2016. Median follow-up was 52 months. The overall incidence rate was found to be 0.12/1,000,000 age adjusted to the 2000 US standard population. More than 50% of the cases were diagnosed after 2010. The median age at diagnosis was 61 years (2-97 years). It was seen most frequently in White (72.9%) patients followed by Hispanic (10.2%) and Black (9.4%) patients. The male to female ratio was 1.42. The most common primary sites affected were the skin of the lower limbs and hip (26.4%) and head and neck (21.3%). A 33.4% of patients required treatment which was mainly excisional (1 patient required amputation). Notably, PCALCL was diagnosed as a second or third malignancy in 19.2% of cases. Overall survival rates at 5 years and 10 years were found to be 80.6% (95% CI: 76.3%, 84.3%) and 61.5% (95% CI: 54.1%, 68.1%) respectively. Age greater than 60 years old was significantly associated with a lower survival (89.7% vs 54.4%, p<0.0001). Survival was not significantly different if head and neck was the site of the primary lesion (64.2% vs 60.8%, p = 0.4371). Conclusion Our analysis of the SEER database for PCALCL is the largest done to our knowledge. Although the number of cases has almost tripled since 2005, it is still a rare type of cutaneous T-cell lymphoma. Lower extremities and hips are the most frequent primary skin site. Only a third of the patients required treatment with overall survival rates of more than 80% by 5 years. Older age (more than 60 years old) is associated with a worse outcome. Head and neck as the primary skin site does not appear to be associated to lower survival as previously thought. Disclosures No relevant conflicts of interest to declare.