The impact of temperature on the skin barrier and atopic dermatitis

Graded anthropomorphic pain perception electronic skin

As a smart product with flexible, stretchable, and multifunctional sensing properties, electronic skin (e-skin) has made significant research progress in many fields, such as robotics, medical monitoring, and human-computer interaction. However, the current e-skin still has obvious deficiencies in simulating pain perception, especially the limitation in simulating human pain grading perception. In this study, the theory of medical pain grading is applied to the field of e-skin for the first time, and an e-skin system with gradable human-like pain perception is proposed. The system comprises a sensor perception module, an information acquisition module, a neural network processing module, and a visualization feedback module. By combining the electronic skin with neural network technology, the system not only realizes the basic pain grading function but also can adjust the adaptive pain perception according to the environmental temperature change. This study provides a feasible solution for developing graded human-like pain-sensing technology in the fields of intelligent prosthetics, medical monitoring, and human-computer interaction.

Seasonal Variation of the Burden of Atopic Dermatitis in Finnish Primary Care: A Database Study on Effects of Weather and Air Quality

The burden of atopic dermatitis has been increasing in Finland during recent decades and seems to vary seasonally. The aim was to investigate the effect of season and weather factors on patient numbers of primary care. Data bank information of the Finnish Institute for Health and Welfare was analysed for frequency of atopic dermatitis patients in the primary care of Helsinki during 2018-2023. In addition, the seasonal burden was compared with weather data from the Finnish Meteorological Institute. Patient numbers varied significantly during the year (p = 0.028). There was a recurrent seasonal variation with most atopic dermatitis diagnoses in January, February, March, and November and the least in July and August. A significant inverse association was observed between atopic dermatitis patients and outside temperature (p = 0.004) and UV Index (p = 0.008). Low air quality was associated with a higher burden in primary care (p = 0.013). There was no significant association regarding rain (p = 0.103) or relative air humidity (p = 0.392). The burden of atopic dermatitis in primary care shows a significant seasonal variation. There are specific weather parameters that follow similar patterns and likely comprise important extrinsic pathogenetic factors. It is reasonable to address the changing burden of atopic dermatitis with seasonally directed medical measures, education, and resources.

Efficacy in Clinical Studies of a Skin Care Serum Formula Containing 7 Short and Long Saccharides and Bacterial Fractions to Repair and Strengthen the Skin Barrier From Aggressions in Intense Conditions

BACKGROUND

A healthy skin barrier is essential to protect against the entry of harmful substances or the loss of internal fluids, especially water and electrolytes. Various aggressions are known to weaken the skin barrier.

AIMS

To evaluate single or multiple applications of a serum formula designed to mitigate skin barrier dysfunction and improve recovery after exposure to three different external aggressions (including one cumulative aggression under intense conditions).

PATIENTS AND METHODS

Five single-blind, controlled, intra-individual clinical studies in healthy subjects evaluated the effect of serum formula vs. untreated skin after aggression with harsh cleanser, emery paper abrasion, or tape stripping followed by exposure to 4°C or 40°C. Skin barrier function was assessed by transepidermal water loss (TEWL) and skin pH.

RESULTS

After harsh cleanser aggression, significant improvements in pH recovery and TEWL were observed after serum application, vs. untreated control, indicating significantly faster skin barrier recovery. Similarly, after tape stripping followed by intense cold or hot conditions, barrier function recovery was also significantly faster with an application of serum versus untreated control. In addition, serum-treated skin was more resistant against abrasion after serum treatment compared to the untreated control.

CONCLUSIONS

The serum formula, containing a unique combination of seven short and long saccharides and bacterial fractions, helped repair and strengthen the skin barrier to protect against abrasion. Taken together, these studies showed improved skin barrier recovery after exposure to different types of aggression (harsh cleanser or cumulative aggression by tape stripping followed by intense cold or hot conditions).

Possibility and Potenzial Intervention Targets of Saffron Extract in the Treatment of Atopic Dermatitis: A Review

Atopic dermatitis (AD) is a chronic, recurrent inflammatory skin disorder characterized by dry skin, eczema-like lesions, and severe itching. The multifaceted etiology of AD, which is not yet fully understood, includes genetic predispositions, immune dysfunctions(such as an impaired skin barrier and abnormal immune regulation), imbalances in the skin microbiota, and environmental factors, among others. In the field of AD treatment, the combination of traditional Chinese medicine and modern medicine is becoming an emerging trend. Given the potenzial side effects and reduced efficacy of conventional therapeutic drugs, Chinese herbal medicines offer patients new treatment options because of their unique efficacy and low toxicity. Some saffron extracts derived from saffron and gardenia, such as crocin, crocetin, and safranal, have shown promising potenzial in the treatment of AD. These natural ingredients not only possess anti-inflammatory and immunomodulatory properties similar to those of traditional Chinese medicines but also demonstrate excellent effects in promoting the repair of damaged skin barriers. Therefore, this article reviews the therapeutic potenzial of saffron extract in the treatment of AD, with a special focus on its mechanisms and potenzial interventions, while emphasizing the importance of herbal medicines as alternatives to traditional treatments, providing AD patients with safer and more effective treatment options.

Head and neck dermatitis: a variant of atopic dermatitis

Atopic dermatitis involves the head and neck area across all age groups. This manifestation is frequently referred to as "the head and neck dermatitis." Aside from a considerable deterioration of the quality of life, it poses a significant diagnostic and therapeutic challenge. The head and neck dermatitis may be mimicked by other inflammatory conditions such as seborrheic dermatitis or contact dermatitis. Furthermore, it can be associated with a wide range of infectious, ocular, psychiatric and hair disorders, which should raise clinical alertness and encourage a multidisciplinary management of the affected individuals. Skin lesions in the head and neck area are often difficult to treat, particularly because of a considerable exposure of this region to exacerbating factors and limitations regarding the use of some pharmaceuticals. Although several hypotheses explaining the recalcitrant course of head and neck dermatitis have been proposed, none of them provide successful solutions applicable in the daily clinical practice. This comprehensive review comprises the current insights on the pathogenesis, clinical presentation, and comorbidities of the head and neck dermatitis. Recommendations regarding possible treatments of this condition such as antifungals, as well as special considerations for the choice of biologics or JAK inhibitors in the candidates for systemic treatment are outlined.

From Rash Decisions to Critical Conditions: A Systematic Review of Dermatological Presentations in Emergency Departments

Background: Dermatological emergencies are critical conditions requiring immediate attention due to their potential to escalate into life-threatening scenarios. Accurate diagnosis and timely management are essential to prevent severe complications, including systemic involvement and mortality. This systematic review summarizes findings on dermatological emergencies in emergency departments (EDs), focusing on diagnostic accuracy, hospitalization rates, systemic complications, and management strategies. Methods: A systematic literature review of studies on dermatological emergencies was conducted, encompassing 24 prospective and retrospective cohort studies, cross-sectional studies, and descriptive analyses. The review included diverse patient populations, examining dermatological presentations, diagnostic methods, treatment strategies, hospitalization rates, and adverse outcomes. Key outcome measures such as diagnostic accuracy, complications, mortality rates, and re-visit frequencies were analyzed. Results: The studies revealed high diagnostic accuracy, particularly in in-person evaluations, with teledermatology showing slightly lower but reliable rates. Systemic complications, including severe drug reactions, bacterial infections, and autoimmune diseases, were common causes of hospitalization. Mortality rates varied, with conditions such as toxic epidermal necrolysis showing the highest risk. Hospitalization rates averaged 4.52%, and re-visit rates ranged from 1% to 6.5%. The results also highlighted the impact of environmental factors and seasonal trends on dermatological presentations. Conclusions: Dermatological emergencies pose significant challenges in emergency care. High diagnostic accuracy and effective management strategies are crucial in preventing severe outcomes. Timely diagnosis, careful management of systemic complications, and teledermatology play critical roles in improving care. Future research should focus on standardized management protocols, telemedicine applications, and the influence of environmental and demographic factors to enhance patient outcomes.

TRPV3 in skin thermosensation and temperature responses

Human skin, as a sophisticated sensory organ, is able to detect subtle changes in ambient temperature. This thermosensory capability is primarily mediated by temperature-sensitive TRP channels expressed in both sensory neurons and keratinocytes. Among these, TRPV3, which responds to warm temperatures and plays a crucial role in various skin functions, is particularly notable. TRPV3 channels not only detect moderate warmth but are also sensitive to chemical ligands that evoke thermal sensations. The activation of TRPV3 by warm temperatures and compounds highlights its importance in the molecular mechanisms underlying skin thermosensation. This review mainly discusses the role of TRPV3, particularly its contribution to skin thermosensation and structural insights into its temperature sensitivity, providing an understanding of how TRPV3 modulates thermal perception at the molecular level.

Using Smartphone Data to Frequently Measure Atopic Dermatitis Severity and Understand Triggers: A Decentralized 12-Week Observational Study

INTRODUCTION

Atopic dermatitis (AD) severity is traditionally evaluated during in-office consultations; however, this does not provide continuous monitoring and any intermittent flare/remission cycles are usually not recorded. The aim was to apply smartphone technology to evaluate AD severity, to explore if severity based on highly frequent sampling of photographs is associated with patient reported outcomes, and to investigate disease fluctuations and trigger associations based on passively collected environmental data.

METHODS

In this 12-week decentralized observational study, adult patients with AD were recruited online and used a tailored remote clinical trial platform app to perform all study tasks including capturing photographs and completing the Patient-Oriented Eczema Measure (POEM) weekly. AD severity was assessed based on photographs using the Eczema Area and Severity Index (EASI) and Scoring Atopic Dermatitis (SCORAD). Geographical location collected in the app was used to retrieve data on ambient temperature and carbon monoxide (CO), a common air pollutant.

RESULTS

A total of 42 patients (35 women) were recruited online. A total of 712 photographs were taken, with an average of 17 photographs per participant. Photographic SCORAD (r = 0.450) and EASI (r = 0.206) were significantly associated with subjective severity POEM. Patients experiencing AD fluctuation (n = 10) based on SCORAD had significantly higher risk of also having a psychiatric disorder (60 vs. 17%, p = 0.008). Anxiety was significantly associated with disease fluctuation based on EASI (40 vs. 7%, p = 0.01), and a tendency was observed for depression (40 vs. 13%, p = 0.06). Decreasing temperature was significantly associated with higher POEM (estimate -0.18, p = 0.012) and EASI score (estimate -0.14, p = 0.007), but not with SCORAD. High levels of CO were significantly associated with higher SCORAD (estimate 15.9, p < 0.001).

CONCLUSION

In this small study with a predominance of young adults, primarily women, we were able to recruit patients and monitor AD entirely remotely via smartphone-enabled photographic assessments; patients reported outcomes and passively collected environmental data without physical contact between patient and investigator.

Anoctamin 1, a multi-modal player in pain and itch

Anoctamin 1 (ANO1/TMEM16A) encodes a Ca2+-activated Cl- channel. Among ANO1's many physiological functions, it plays a significant role in mediating nociception and itch. ANO1 is activated by intracellular Ca2+ and depolarization. Additionally, ANO1 is activated by heat above 44 °C, suggesting heat as another activation stimulus. ANO1 is highly expressed in nociceptors, indicating a role in nociception. Conditional Ano1 ablation in dorsal root ganglion (DRG) neurons results in a reduction in acute thermal pain, as well as thermal and mechanical allodynia or hyperalgesia evoked by inflammation or nerve injury. Pharmacological interventions also lead to a reduction in nocifensive behaviors. ANO1 is functionally linked to the bradykinin receptor and TRPV1. Bradykinin stimulates ANO1 via IP3-mediated Ca2+ release from intracellular stores, whereas TRPV1 stimulates ANO1 via a combination of Ca2+ influx and release. Nerve injury causes upregulation of ANO1 expression in DRG neurons, which is blocked by ANO1 antagonists. Due to its role in nociception, strong and specific ANO1 antagonists have been developed. ANO1 is also expressed in pruritoceptors, mediating Mas-related G protein-coupled receptors (Mrgprs)-dependent itch. The activation of ANO1 leads to chloride efflux and depolarization due to high intracellular chloride concentrations, causing pain and itch. Thus, ANO1 could be a potential target for the development of new drugs treating pain and itch.

TRPV4-A Multifunctional Cellular Sensor Protein with Therapeutic Potential

Transient receptor potential vanilloid (TRPV) channel proteins belong to the superfamily of TRP proteins that form cationic channels in the animal cell membranes. These proteins have various subtype-specific functions, serving, for example, as sensors for pain, pressure, pH, and mechanical extracellular stimuli. The sensing of extracellular cues by TRPV4 triggers Ca2+-influx through the channel, subsequently coordinating numerous intracellular signaling cascades in a spatio-temporal manner. As TRPV channels play such a wide role in various cellular and physiological functions, loss or impaired TRPV protein activity naturally contributes to many pathophysiological processes. This review concentrates on the known functions of TRPV4 sensor proteins and their potential as a therapeutic target.

The clinical, mechanistic, and social impacts of air pollution on atopic dermatitis

Atopic dermatitis (AD) is a complex disease characterized by dry, pruritic skin and significant atopic and psychological sequelae. Although AD has always been viewed as multifactorial, early research was dominated by overlapping genetic determinist views of either innate barrier defects leading to inflammation or innate inflammation eroding skin barrier function. Since 1970, however, the incidence of AD in the United States has increased at a pace that far exceeds genetic drift, thus suggesting a modern, environmental etiology. Another implicated factor is Staphylococcus aureus; however, a highly contagious microorganism is unlikely to be the primary etiology of a noncommunicable disease. Recently, the roles of the skin and gut microbiomes have received greater attention as potentially targetable drivers of AD. Here too, however, dysbiosis on a population scale would require induction by an environmental factor. In this review, we describe the evidence supporting the environmental hypothesis of AD etiology and detail the molecular mechanisms of each of the AD-relevant toxins. We also outline how a pollution-focused paradigm demands earnest engagement with environmental injustice if the field is to meaningfully address racial and geographic disparities. Identifying specific toxins and their mechanisms can also inform in-home and national mitigation strategies.

Climate change from the Asia-Pacific perspective: What an allergist needs to know and do

Allergic diseases such as asthma, atopic dermatitis, and food allergies are a burgeoning health challenge in the Asia-Pacific region. Compounding this, the region has become increasingly susceptible to the impacts of climate change. The region has weathered extreme precipitation, intense heat waves, and dust storms over the recent decades. While the effects of environmental and genetic factors on allergic diseases are well understood, prevailing gaps in understanding the complex interactions between climate change and these factors remain. We aim to provide insights into the various pathways by which climate change influences allergic diseases in the Asia-Pacific population. We outline practical steps that allergists can take to reduce the carbon footprint of their practice on both a systemic and patient-specific level. We recommend that allergists optimize disease control to reduce the resources required for each patient's care, which contributes to reducing greenhouse gas emissions. We encourage the responsible prescription of metered dose inhalers by promoting the switch to dry powder inhalers for certain patients, at each clinician's discretion. We also recommend the utilization of virtual consultations to reduce patient travel while ensuring that evidence-based guidelines for rational allergy management are closely adhered to. Finally, eliminating unnecessary testing and medications will also reduce greenhouse gas emissions in many areas of medical care.

Skin as the target for allergy prevention and treatment

The fact that genetic and environmental factors could trigger disruption of the epithelial barrier and subsequently initiate a TH2 inflammatory cascade conversely proposes that protecting the same barrier and promoting adequate interactions with other organs, such as the gut, may be crucial for lowering the risk and preventing atopic diseases, particularly, food allergies. In this review, we provide an overview of structural characteristics that support the epithelial barrier hypothesis in patients with atopic dermatitis, including the most relevant filaggrin gene mutations, the recent discovery of the role of the transient receptor potential vanilloid 1, and the role involvement of the microbiome in healthy and damaged skin. We present experimental and human studies that support the mechanisms of allergen penetration, particularly the dual allergen exposure and the outside-in, inside-out, and outside-inside-outside hypotheses. We discuss classic skin-targeted therapies for food allergy prevention, including moisturizers, steroids, and topical calcineurin inhibitors, along with pioneering trials proposed to change their current use (Prevention of Allergy via Cutaneous Intervention and Stopping Eczema and ALlergy). We provide an overview of the novel therapies that enhance the skin barrier, such as probiotics and prebiotics topical application, read-through drugs, direct and indirect FLG replacement, and interleukin and janus kinases inhibitors. Last, we discuss the newer strategies for preventing and treating food allergies in the form of epicutaneous immunotherapy and the experimental use of single-dose of adeno-associated virus vector gene immunotherapy.

Impact of climate change on atopic dermatitis: A review by the International Eczema Council

Atopic dermatitis (AD), the most burdensome skin condition worldwide, is influenced by climatic factors and air pollution; however, the impact of increasing climatic hazards on AD remains poorly characterized. Leveraging an existing framework for 10 climatic hazards related to greenhouse gas emissions, we identified 18 studies with evidence for an impact on AD through a systematic search. Most climatic hazards had evidence for aggravation of AD the impact ranged from direct effects like particulate matter-induced AD exacerbations from wildfires to the potential for indirect effects like drought-induced food insecurity and migration. We then created maps comparing the past, present, and future projected burden of climatic hazards to global AD prevalence data. Data are lacking, especially from those regions most likely to experience more climatic hazards. We highlight gaps important for future research: understanding the synergistic impacts of climatic hazards on AD, long-term disease activity, the differential impact on vulnerable populations, and how basic mechanisms explain population-level trends.

The Prevention of House Dust Mite Allergies in Pediatric Asthma

This review provides a concise overview of preventive measures against dust mite allergies in pediatric populations, emphasizing the need for a comprehensive and evolving approach. Dust mites, ubiquitous microscopic arachnids, pose a significant threat to children's health, triggering allergies and asthma. Traditional preventive strategies such as regular cleaning, mattress covers, and humidity control are essential but warrant refinement. Empowering children through personalized hygiene education and exploring innovative bedding solutions showcase a forward-thinking paradigm. Collaboration with healthcare professionals and embracing technology-driven solutions ensures a holistic and adaptable approach to safeguarding pediatric health against dust mite-related ailments. This abstract underscores the importance of continually reassessing and innovating preventive measures to create resilient and health-conscious living environments for children.

Filaggrin and beyond: New insights into the skin barrier in atopic dermatitis and allergic diseases, from genetics to therapeutic perspectives

Atopic dermatitis (AD) is the most common inflammatory skin disease worldwide, affecting 20% of children and 5% of adults. One critical component in the pathophysiology of AD is the epidermal skin barrier, with its outermost layer, the stratum corneum (SC), conferring biochemical properties that enable resilience against environmental threats and maintain homeostasis. The skin barrier may be conceptualized as a key facilitator of complex interactions between genetics, host immunity, the cutaneous microbiome, and environmental exposures. The key genetic risk factor for AD development and persistence is a loss-of-function mutation in FLG, with recent advances in genomics focusing on rare variant discovery, establishment of pathogenic mechanisms, and exploration of the role of other epidermal differentiation complex gene variants in AD. Aberrant type 2 inflammatory responses down-regulate the transcription of key epidermal barrier genes, alter the composition of SC lipids, and induce further injury through a neurocutaneous feedback loop and the itch-scratch cycle. The dysbiotic epidermis exhibits reduced bacterial diversity and enhanced colonization with Staphylococcus and Malassezia species, which contribute to both direct barrier injury through the action of bacterial toxins and perpetuation of the inflammatory cascades. Enhanced understanding of each of the pathogenic mechanisms underpinning barrier disruption has led to the development of novel topical and systemic molecules, including interleukin (IL)-4Ra, IL-13, PDE4, and Janus-associated kinase inhibitors, whose clinical effectiveness exceeds conventional treatment modalities. In this narrative review, we aim to summarize the current understanding of the above-mentioned pathophysiological and therapeutic mechanisms, with a focus on the genetic, cellular, and molecular mechanisms underpinning AD development.

The Burden of Air Pollution on Skin Health: a Brief Report and Call to Action

INTRODUCTION

Air pollution in North America has intensified due to wildfires in recent years. In 2023, the wildfires in the Canadian province of Quebec caused a southward spread of pollutants, negatively affecting air quality and thereby aggravating certain health conditions in northeastern USA. This study examines the impact of air pollution on atopic dermatitis (AD) and skin health and how wildfires can exacerbate the burden of disease.

METHODS

Carbon monoxide levels measured by the U.S. Environmental Protection Agency (EPA) in the Boston region during the months following the Canadian wildfires of 2023 were collected from the U.S. EPA Outdoor Air Quality webpage. Patient records on dermatology clinic visits for dermatitis and eczema at the Mass General Brigham (MGB) hospital system, 300 miles from the wildfires, were examined, and the data compared with data from the corresponding months in 2019-2022 for historical control. No individual patient data were collected.

RESULTS

A notable rise and atypical summer peak in carbon monoxide (CO) levels in the Boston region during 2023 correlated with a spike in AD, dermatitis, and eczema-related dermatology clinic visits within the MGB hospital system, as compared with the prior 4 years.

CONCLUSION

The synchronized atypical peaks of CO levels and AD-related visits during the summer of 2023 highlight the potential impact of acute air pollution events such as wildfires on air quality and the consequences for skin health. Air pollution, exacerbated by wildfires, can damage the skin through the smoke and chemicals utilized for extinguishing fires, which contain multiple potential allergens and irritants to the skin, such as CO, particulate matter (PM2.5), and ammonium phosphates, triggering airway and skin inflammation and flares of AD. This issue disproportionately affects vulnerable populations, including low-income communities and the geriatric and pediatric populations. Healthcare professionals and government agencies must work together to improve air quality and purification policies and initiatives to lower the burden of skin disease, especially for vulnerable communities.

Targeting Transient Receptor Potential (TRP) Channels, Mas-Related G-Protein-Coupled Receptors (Mrgprs), and Protease-Activated Receptors (PARs) to Relieve Itch

Itch (pruritus) is a sensation in the skin that provokes the desire to scratch. The sensation of itch is mediated through a subclass of primary afferent sensory neurons, termed pruriceptors, which express molecular receptors that are activated by itch-evoking ligands. Also expressed in pruriceptors are several types of Transient Receptor Potential (TRP) channels. TRP channels are a diverse class of cation channels that are responsive to various somatosensory stimuli like touch, pain, itch, and temperature. In pruriceptors, TRP channels can be activated through intracellular signaling cascades initiated by pruritogen receptors and underly neuronal activation. In this review, we discuss the role of TRP channels TRPA1, TRPV1, TRPV2, TRPV3, TRPV4, TRPM8, and TRPC3/4 in acute and chronic pruritus. Since these channels often mediate itch in association with pruritogen receptors, we also discuss Mas-related G-protein-coupled receptors (Mrgprs) and protease-activated receptors (PARs). Additionally, we cover the exciting therapeutic targets amongst the TRP family, as well as Mrgprs and PARs for the treatment of pruritus.