How does epidermal pathology interact with mental state?

Human sweat contains oxytocin

BACKGROUND

Oxytocin (OT) has been detected in various body fluids, including blood, urine, saliva, breastmilk, and spinal fluid. Consistent with models that regard skin as a social organ and in line with studies demonstrating that skin cells express both OT and its receptor, our study sought to examine the presence of OT in human sweat.

METHODS

Overall, 553 individuals participated in a pilot study and three experiments. Firstly, 50 participants provided sweat after engaging in various sports for different durations. Secondly, 26 participants provided sweat from forehead, upper-chest, forearm, and underarm, including 11 in natural setting and 15 following OT administration and a 30-minute exercise. Thirdly, of 435 volunteers, 97 provided sufficient axillary sweat for assaying. Of these, 84 participated in a naturalistic experiment that involved saliva and sweat collection in response to physical activity in either solitary or social settings. OT and testosterone (TS) were assayed in sweat and saliva.

RESULTS

Intense activity for at least 25 min was required to produce sufficient sweat for OT analysis. Highest OT levels were found in axillary sweat compared to sweat from the forehead, upper-chest, and forearm. Salivary OT and TS increased after both solitary and social physical activity; however, higher sweat OT was found after solitary sports. Post-hoc preliminary findings indicate that highly extroverted individuals exercising in solitary environments showed the highest sweat OT levels.

CONCLUSIONS

Findings demonstrate, for the first time, the presence of OT in human sweat and show the feasibility of its measurement. Much further research is required to illuminate how sweat OT is impacted by personality and social context and to uncover the role of the skin in OT production.

Ectodermal origins of the skin-brain axis: a novel model for the developing brain, inflammation, and neurodevelopmental conditions

Early life development and its divergence is influenced by multiple genetic, neurological, and environmental factors. Atypical neurodevelopment, such as that observed in autism spectrum disorder, likely begins in early gestation during a period of entwined growth between the brain and epithelial barriers of the skin, gastrointestinal tract, and airway. This review coalesces epidemiological and neuroinflammatory evidence linking cutaneous atopic disease with both reduced skin barrier integrity and determinants of neurodivergence. We consider the shared developmental origin of epidermal and neural tissue with related genetic and environmental risk factors to evaluate potential pre- and postnatal modifiers of the skin-brain connection. Initial postnatal skin barrier integrity may provide a useful marker for both cortical integrity and meaningful subgroups of children showing early neurodevelopmental delays. It may also modify known risk factors to neurodevelopment, such as pathogen caused immune system activation. These novel insights of a skin-brain-neurodevelopment connection may advance detection and intervention opportunities.

Do epidermal keratinocytes have sensory and information processing systems?

It was long considered that the role of epidermal keratinocytes is solely to construct a water-impermeable protective membrane, the stratum corneum, at the uppermost layer of the skin. However, in the last two decades, it has been found that keratinocytes contain multiple sensory systems that detect environmental changes, including mechanical stimuli, sound, visible radiation, electric fields, magnetic fields, temperature and chemical stimuli, and also a variety of receptor molecules associated with olfactory or taste sensation. Moreover, neurotransmitters and their receptors that play crucial roles in the brain are functionally expressed in keratinocytes. Recent studies have demonstrated that excitation of keratinocytes can induce sensory perception in the brain. Here, we review the sensory and information processing capabilities of keratinocytes. We discuss the possibility that epidermal keratinocytes might represent the earliest stage in the development of the brain during the evolution of vertebrates.

Association between skin disorders and depression in children and adolescents: A retrospective case-control study

BACKGROUND

The aim of this study was to investigate the association between skin disorders and depression in children and adolescents in Germany.

METHODS

This retrospective case-control study was based on data from the Disease Analyzer database (IQVIA). The present study included children and adolescents diagnosed for the first time with depression in 185 pediatric practices between January 2017 and December 2019 (index date) and matched controls without depression. Chronic skin conditions documented within 12 months prior to the index date (i.e. date of first depression diagnosis) were included in the analyses if their prevalence was at least 0.5% in the study population. Associations between nine different skin disorders and depression (dependent variable) were analyzed in a conditional logistic regression model.

RESULTS

This study included 7,061 cases with depression and 7,061 matched controls without depression (mean age 11.3 (SD: 3.8) years; 53.4% female). Three disorders were significantly associated with depression: atopic dermatitis/eczema (OR = 1.50, 95% CI = 1.37-1.64), nail disorders (OR = 1.84, 95% CI = 1.20-2.82), and hair loss (OR = 1.84, 95% CI = 1.30-2.60). In sex-stratified regression analyses, atopic dermatitis/eczema (OR = 1.43, 95% CI = 1.26-1.61) and hair loss (OR = 2.04, 95% CI = 1.37-3.03), were significantly associated with depression in females, since only atopic dermatitis/eczema was associated with depression (OR = 1.58, 95% CI = 1.39-1.80) in males. However, strong non-significant association was additionally observed for nail disorders (OR = 2.07, 95% CI = 1.07-4.01), and pigmentation disorders (OR = 1.93, 95% CI = 1.05-3.54) in females.

CONCLUSIONS

Some skin disorders are positively associated with depression in children and adolescents. Further research is needed for better understanding of the underlying mechanisms and mediating factors.

Biological Sex and IgE Sensitization Influence Severity of Depression and Cortisol Levels in Atopic Dermatitis

BACKGROUND

Depression is a common comorbid condition with atopic dermatitis (AD), particularly during the active disease cycle. Controversial results regarding the contribution of biological sex, immunoglobulin E (IgE) sensitization, and cortisol on AD severity and comorbid depression justify further investigation.

OBJECTIVE AND METHODS

To explore the influence of sex and IgE sensitization on biochemical and psychological parameters, and severity of AD, a case-control study of 105 volunteers (56 AD, 49 healthy controls (HC); 50 males, 55 females) was conducted over 10 weeks, starting at dermatological symptom onset. Disease severity, serum IgE, cortisol and testosterone levels, and depression scores were assessed at study baseline and after 10 weeks of conventional treatment.

RESULTS

Dermatological severity differed among AD males by IgE sensitization and was elevated in males with extrinsic atopic dermatitis (EAD). Hamilton Depression Rating Scale (HAMD) scores were elevated in all patients at study baseline and improved with symptom reduction to HC levels, except female EAD. Severity of depression and dermatitis were correlated in EAD males at baseline and at week 10. Serum cortisol was elevated in male EAD at baseline, in contrast to males with intrinsic atopic dermatitis (IAD) at week 10. In addition, cortisol levels were found negatively correlated with SCORAD and HAMD scores in EAD males at week 10.

CONCLUSION

Pathophysiological features of AD and depression are likely related to different inflammation-based effects and appear to be biological sex-dependent. Cortisol levels depend on biological sex and IgE sensitization in AD and increase in males with EAD at exacerbation and IAD males at resolution. Biological sex-related disease triggers, IgE sensitization, and cortisol levels are important for the understanding of the mechanisms underlying AD and comorbid depression.

Narrow-band ultraviolet B (NB UV-B) exposures improve mood in healthy individuals differently depending on chronotype

The evening chronotype is associated with psychological symptoms such as depressed mood, while skin exposure to ultraviolet radiation (UVR) may affect mood and behavior through neural and humoral routes. This pilot study aimed to investigate the impact of whole-body narrow-band (NB) UV-B exposure on current mood state and circulating 25-hydroxyvitamin D3 (25(OH)D₃), interleukin-6 (IL-6), cortisol and β-endorphin (β-END) levels in healthy participants. Here, eleven healthy women received full-body NB UV-B exposures on four afternoons, and the chronotype was assessed with a shortened version of Horne and Östberg's Morningness-Eveningness Questionnaire (MEQ). Perceived mood was evaluated using the Visual Analogue Scale (VAS), and serum 25(OH)D₃, IL-6, cortisol and β-END concentrations were monitored daily. Decreasing VAS values showed mood to improve significantly over the five days after the four suberythematous NB UV-B exposures (p = .038), and the more the circadian preference was inclined toward eveningness, the greater the improvement in the mood dimension of wellbeing (p = .021). Baseline mood state was correlated with baseline 25(OH)D₃ (r = -0.54, 95% CI: -0.86 to -0.09) and with baseline cortisol (r = -0.57, 95% CI: -0.87 to -0.04). During the NB UV-B exposures, 25(OH)D₃ increased significantly, as expected, and IL-6 declined significantly by -0.35 (95% CI: -0.69 to -0.07) pg/mL from the initial values of 1.12 ± 0.66 pg/mL (p = .025). In conclusion, in our pilot study, NB UV-B exposure improved mood, especially among those with evening preference for their daily activities, as well as circulating 25(OH)D₃ levels, whereas circulating IL-6 levels decreased. Abbreviations: UVR: Ultraviolet radiation; NB UV-B: narrow-band UV-B; VAS: Visual Analogue Scales; β-END: β-endorphin; IL-6: Interleukin-6.

Introduction

Atopic dermatitis (AD) is a chronic relapsing condition that is characterized by itching and redness of the skin. Our modern usage of atopic dermatitis dates back to 1933, when Wise and Sulzberger first coined the term to signify the disease's close association with other respiratory atopy, such as bronchial asthma and allergic rhinitis. A recent systematic review of 69 cross-sectional and cohort studies has confirmed that AD is now a worldwide phenomenon with lifetime AD prevalences of well over 20% in many affluent country settings. Although there is no obvious consistent overall global trend in the prevalence of AD, studies have shown that climate, urbanization, lifestyle, and socioeconomic class influence the prevalence of atopic dermatitis. Despite the pervasiveness of the disease, an understanding of atopic dermatitis has been hampered by a number of factors. Data suggests that extrinsic environmental factors work in concert with intrinsic immune mechanism and genetic factors to drive disease progression. With such a complex etiology, management of atopic dermatitis currently at best achieves symptomatic control rather than cure. This approach poses a significant burden on healthcare resources, as well as patients' quality of life. Current management methods of AD often involves a combination of non-pharmacologic modalities and prescription medications. Though they can be effective when employed, there are significant barriers to treatment for patients including time, costs, and medication side effects. Our aim, throughout this text, is to explore the complexities of AD, providing the healthcare provider with tips and tricks to improve patient care and satisfaction and the most current trends and treatment approaches on the horizon.

Skin microbiome & host immunity: applications in regenerative cosmetics & transdermal drug delivery

Recent advances in our understanding of the function of the skin and its microbiome have shown that there is a strong symbiotic relationship between the microbiota of the skin and its host immune functions. The dysbiosis or imbalance of the microbiome and other factors that have an influence on the surface microbiota can influence keratinocyte regulation and homeostasis as well as the skin barrier function. In this perspective paper, we review the evidence that connects the skin's microbiome and the barrier function of the epidermis and explore the future potential for applying this unique dialogue in developing innovative cosmetics and transdermal drugs for wellbeing and beauty.

The microbiome on the skin has a unique dialogue with the host through the host immune system. This dialogue makes the basis of several host immune responses and help shape the host immunity. In this article, we explore this microbiome and host interaction, and see how this can influence our understanding of skin barrier function, and future applications toward transdermal delivery of topicals.

Psychiatry outpatient visits by atopic dermatitis patients varying in the complexity of their prescriptions: A nationwide cohort study conducted from 2005 to 2013

The uncomfortable symptoms of atopic dermatitis (AD) often trigger psychological stress.We investigated the association between AD severity and outpatient visits to psychiatrists using Korean National Health Insurance claims data from 2004 to 2013.This was a retrospective cohort analysis; we estimated hazard ratios (HRs).Of the 266,182 subjects, 18,290 (6.9%) had a history of visiting a psychiatrist, and 25,419 (9.5%) were diagnosed with AD. Compared with the subjects without AD, subjects with AD had a higher HR for visiting a psychiatrist (3.70, 95% confidence interval [CI]:48 3.43-3.98), and this significantly increased as the complexity of the AD medications increased. Subjects who received topical treatments plus a systematic steroid (HR: 4.88, 95% CI: 4.51-5.27) and those who received topical treatments plus a systematic steroid plus a systematic calcineurin inhibitor (HR: 9.56, 95% CI: 4.29-21.28) had higher HRs compared with those without AD.Severe AD patients exhibited greater psychological stress than those without AD or with mild AD symptoms. Moreover, medication diversity may represent an efficient and low-cost method by which to identify a vulnerable population.