Delta opioid receptor expression correlates to skin ageing and melanin expression in Asian women.

While the evidence for the implication of opioid receptors (OPr) in ageing is growing, there is, to our knowledge, no study focusing directly on changes in vivo cutaneous OPr expression with increasing age. We thus investigated OPr expression in 30 healthy female Asian volunteers in Southern China whose ages range from the early 20s to the early 60s. Excisional biopsies were taken from the sun-exposed extensor area of the lower arm and the photo-protected area of the upper inner arm.

Demonstration of Convolutional Neural Networks to Determine Patch Test Reactivity.

Convolutional neural networks (CNNs) have the potential to assist allergists and dermatologists in the analysis of patch tests. Such models can help reduce interprovider variability and improve consistency of patch test interpretations. Our aim is to evaluate the performance of a CNN model as a proof of concept in discriminating between patch tests with reactions and patch tests without reactions.

Honey flower dermatitis: Contact allergy to ellagic acid in Melianthuscomosus.

A case study is reported whereby a patient with no prior allergies developed a strong and spreading delayed-type hypersensitivity reaction to Melianthus plants, nectar and synthetic pigment derived from it after frequent handling of these substances. The lesions improved after treatment with topical steroids and allergen avoidance within 1-2 weeks. Subsequent patch testing with the plants, nectar and synthetic ingredients identified ellagic acid (EA) as the sensitizing agent.

The Diagnostic Value of Delayed-Type Reactions to Perennial Aeroallergens for Atopic Disease.

Delayed-type reactions to aeroallergens have been observed, however, their clinical significance continues to be debated. We assessed the prevalence and significance of delayed-type reactions to aeroallergens in atopic patients. Retrospective study including 266 patients with history or evidence of atopic disease (atopic dermatitis [AD], allergic rhinitis, and/or allergic asthma) and tested via either the intradermal skin test (IDT) or atopy patch test for common aeroallergens, specifically house dust mites (, ) and perennial molds (, ).

Distinct transcriptomic and metabolomic profiles characterize NSAID-induced urticaria/angioedema patients undergoing aspirin desensitization.

Background: There is limited data on the mechanisms of aspirin desensitization in patients with nonsteroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema (NIUA).

Objectives: We sought to characterize the transcriptomic and metabolomic profiles of patients with NIUA undergoing aspirin desensitization.

Methods: PBMCs and plasma were separated from the blood of patients with NIUA undergoing aspirin desensitization for coronary artery disease and NSAID-tolerant controls.

What You Need to Know About Hand Hygiene and Dermatitis During the Coronavirus Pandemic.

Increased attention towards infection control measures during the COVID-19 pandemic have brought to light the dermatological consequences of intensified hand hygiene measures. Healthcare workers are inherently at an increased risk of developing both allergic and irritant contact dermatitis. Individuals with a history of atopy are especially vulnerable given their impaired native skin barriers and increased sensitivities at baseline.

Functionally expressed bitter taste receptor TAS2R14 in human epidermal keratinocytes serves as a chemosensory receptor.

Traditionally, it is theorized that skin sensation is initiated when cutaneous sensory afferents and Merkel cells receive sensory stimuli, while epidermal keratinocytes were deemed to have no role. However, mounting evidence has shown that keratinocytes can initiate skin sensation by receiving sensory stimuli and transmitting sensory information to sensory afferents. Knowledge regarding the mechanisms by which keratinocytes receive exogenous stimuli is limited, with TRP channels and olfactory receptors having been proposed to serve as receptors for exogenous stimuli in keratinocytes.

Atopic Patients Who Fulfilled Rome III Criteria for Irritable Bowel Syndrome Had Higher Animal Danders Sensitization.

Background/aims: The relationship between animal exposure and irritable bowel syndrome (IBS) is debated. Epidemiological studies have shown that atopy is more prevalent in IBS patients and vice versa. We set out to examine the association between animal danders sensitization and IBS-like symptoms in atopic patients.

Progressive expression of PPARGC1α is associated with hair miniaturization in androgenetic alopecia.

Current opinion views androgens as the pathogenic driver in the miniaturization of hair follicles of androgenetic alopecia by interfering with the dermal papilla. This cannot be the sole cause and therefore it is important for therapeutic and diagnostic purposes to identify additional pathways. Comparative full transcriptome profile analysis of the hair bulb region of normal and miniaturized hair follicles from vertex and occipital region in males with and without androgenetic alopecia revealed that next to the androgen receptor as well the retinoid receptor and particularly the PPAR pathway is involved in progressive hair miniaturization.

Microbiome in the hair follicle of androgenetic alopecia patients.

Androgenetic alopecia is the most common form of hair loss in males. It is a multifactorial condition involving genetic predisposition and hormonal changes. The role of microflora during hair loss remains to be understood.

Role of Skin pH in Psoriasis.

Not much is known about the role of skin pH in skin pathophysiology, in particular in psoriasis. However, there is compelling evidence that the epidermal pH can influence the skin homeostasis and affect the skin barrier by changing the activity of cutaneous enzymes and through the modulation of skin inflammation and microbial colonization. This includes the activation of secretory phospholipase A and interaction with the peroxisome proliferators-activated receptor and retinoid pathways.

Full-Thickness Human Skin Equivalent Models of Atopic Dermatitis.

Atopic dermatitis is a chronic inflammatory skin disease caused by complex multifactorial etiology. In the recent years, there have been significant advances in tissue engineering and the generation of in vitro skin models representative of healthy and diseased states. This chapter describes the methodology for the fabrication of in vitro human skin equivalent (HSE) from human keratinocytes and fibroblasts using a fibrin-based dermal matrix and serum-free culture conditions.

Investigating endogenous µ-opioid receptors in human keratinocytes as pharmacological targets using novel fluorescent ligand.

Opioids in skin function during stress response, regeneration, ageing and, particularly in regulating sensation. In chronic pruritus, topical treatment with Naltrexone changes μ-opioid receptor (μ-OR) localization to relieve itch. The molecular mechanisms behind the effects of Naltrexone on μ-OR function in reduction of itching behavior has not been studied.

Specific Targeting of Melanotic Cells with Peptide Ligated Photosensitizers for Photodynamic Therapy.

A strategy combining covalent conjugation of photosensitizers to a peptide ligand directed to the melanocortin 1 (MC1) receptor with the application of sequential LED light dosage at near-IR wavelengths was developed to achieve specific cytotoxicity to melanocytes and melanoma (MEL) with minimal collateral damage to surrounding cells such as keratinocytes (KER). The specific killing of melanotic cells by targeted photodynamic therapy (PDT) described in this study holds promise as a potentially effective adjuvant therapeutic method to control benign skin hyperpigmentation or superficial melanotic malignancy such as Lentigo Maligna Melanoma (LMM).

Physiological Doses of Red Light Induce IL-4 Release in Cocultures between Human Keratinocytes and Immune Cells.

Phototherapy is routinely used for the treatment of various skin conditions and targeted therapy of superficial cancers. However, the molecular mechanisms behind their biological effects and the need for efficacy enhancing photosensitizers are not well addressed. Particularly, not much is known about the inherent effect of light from the visible spectrum on cytokine release and its downstream effects in keratinocytes and immune cells located in skin and therefore exposed to light.

Povidone iodine in wound healing: A review of current concepts and practices.

Background: Of the many antimicrobial agents available, iodophore-based formulations such as povidone iodine have remained popular after decades of use for antisepsis and wound healing applications due to their favorable efficacy and tolerability. Povidone iodine's broad spectrum of activity, ability to penetrate biofilms, lack of associated resistance, anti-inflammatory properties, low cytotoxicity and good tolerability have been cited as important factors, and no negative effect on wound healing has been observed in clinical practice. Over the past few decades, numerous reports on the use of povidone iodine have been published, however, many of these studies are of differing design, endpoints, and quality.

Aging in hair follicle stem cells and niche microenvironment.

Hair graying and hair loss are prominent and common characteristics of the elderly population. In some individuals these processes can significantly impact their quality of life, leading to depression, anxiety and other serious mental health problems. Accordingly, there has been much interest in understanding the complex physiological changes within the hair follicle in the aging individual.

Synthetic Peptide Drugs for Targeting Skin Cancer: Malignant Melanoma and Melanotic Lesions.

Peptides play decisive roles in the skin, ranging from host defense responses to various forms of neuroendocrine regulation of cell and organelle function. Synthetic peptides conjugated to radionuclides or photosensitizers may serve to identify and treat skin tumors and their metastatic forms in other organs of the body. In the introductory part of this review, the role and interplay of the different peptides in the skin are briefly summarized, including their potential application for the management of frequently occurring skin cancers.

Differential Expression between Human Dermal Papilla Cells from Balding and Non-Balding Scalps Reveals New Candidate Genes for Androgenetic Alopecia.

Androgenetic alopecia (AGA) is a common heritable and androgen-dependent hair loss condition in men. Twelve genetic risk loci are known to date, but it is unclear which genes at these loci are relevant for AGA. Dermal papilla cells (DPCs) located in the hair bulb are the main site of androgen activity in the hair follicle.

Opioids and skin homeostasis, regeneration and ageing - What's the evidence?

What has the opioid receptor system, known for beneficial as well as disastrous effects in the central nervous system, to do with skin? The question is appropriate considering the fact that the nervous system and the skin both derive from the ectoderm. As part of the skin neuroendocrine system, the opioid receptor system exemplifies the closeness between the nervous system and the skin. Overexpression of the δ-opioid receptor in keratinocytes yields dysregulation of involucrin, loricrin, and filaggrin, proteins essential to the integrity of the skin barrier.

Structural and Functional Analysis of Intact Hair Follicles and Pilosebaceous Units by Volumetric Multispectral Optoacoustic Tomography.

Visualizing anatomical and functional features of hair follicle development in their unperturbed environment is key in understanding complex mechanisms of hair pathophysiology and in discovery of novel therapies. Of particular interest is in vivo visualization of the intact pilosebaceous unit, vascularization of the hair bulb, and evaluation of the hair cycle, particularly in humans. Furthermore, noninvasive visualization of the sebaceous glands could offer crucial insight into the pathophysiology of follicle-related diseases and dry or seborrheic skin, in particular by combining in vivo imaging with other phenotyping, genotyping, and microbial analyses.

What happens in the skin? Integrating skin permeation kinetics into studies of developmental and reproductive toxicity following topical exposure.

Animal-based developmental and reproductive toxicological studies involving skin exposure rarely incorporate information on skin permeation kinetics. For practical reasons, animal studies cannot investigate the many factors which can affect human skin permeation and systemic uptake kinetics in real-life scenarios. Traditional route-to-route extrapolation is based on the same types of experiments and requires assumptions regarding route similarity.