Natural moisturizing factors in children with and without eczema: Associations with lifestyle and genetic factors

A Novel Recombinant Human Filaggrin Segment (rhFLA-10) Alleviated a Skin Lesion of Atopic Dermatitis

Atopic dermatitis (AD), a prevalent chronic inflammatory skin disorder, is marked by impaired skin barrier function and persistent pruritus. It significantly deteriorates patients' quality of life, making it one of the most burdensome non-lethal skin disorders. Filaggrin plays a crucial role in the pathophysiology of barrier disruption in AD, interacting with inflammatory mediators. It is an integral part of the extracellular matrix architecture, serving to protect the skin barrier and attenuate the inflammatory cascade. In this study, we engineered a novel recombinant human filaggrin (rhFLA-10) expression vector, which was subsequently synthesized and purified. In vitro and ex vivo efficacy experiments were conducted for AD. rhFLA-10, at low concentrations (5 to 20 μg/mL), was non-toxic to HACaT cells, significantly inhibited the degranulation of P815 mast cells, and was readily absorbed by cells, thereby exerting a soothing therapeutic effect. Furthermore, rhFLA-10 demonstrated anti-inflammatory properties (p < 0.05). In vivo, efficacy experiments further substantiated that rhFLA-10 could effectively ameliorate AD in mice and facilitate the repair of damaged skin (p < 0.001). These findings underscore the considerable potential of rhFLA-10 in the treatment of AD.

Characterization of skin barrier defects using infrared spectroscopy in patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is characterized by skin barrier defects that are often measured by biophysical tools that observe the functional properties of the stratum corneum (SC).

OBJECTIVES

To employ in vivo infrared spectroscopy alongside biophysical measurements to analyse changes in the chemical composition of the SC in relation to AD severity.

METHODS

We conducted an observational cross-sectional cohort study where attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy measurements were collected on the forearm alongside surface pH, capacitance, erythema and transepidermal water loss (TEWL), combined with tape stripping, in a cohort of 75 participants (55 patients with AD stratified by phenotypic severity and 20 healthy controls). Common FLG variant alleles were genotyped.

RESULTS

Reduced hydration, elevated TEWL and redness were all associated with greater AD severity. Spectral analysis showed a reduction in 1465 cm-1 (full width half maximum) and 1340 cm-1 peak areas, indicative of less orthorhombic lipid ordering and reduced carboxylate functional groups, which correlated with clinical severity (lipid structure r = -0.59, carboxylate peak area r = -0.50).

CONCLUSIONS

ATR-FTIR spectroscopy is a suitable tool for the characterization of structural skin barrier defects in AD and has potential as a clinical tool for directing individual treatment based on chemical structural deficiencies.

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.

A Review of Moisturizing Additives for Atopic Dermatitis

Atopic dermatitis, the most common form of eczema, is a chronic, relapsing inflammatory skin condition that occurs with dry skin, persistent itching, and scaly lesions. This debilitating condition significantly compromises the patient’s quality of life due to the intractable itching and other associated factors such as disfigurement, sleeping disturbances, and social stigmatization from the visible lesions. The treatment mainstay of atopic dermatitis involves applying topical glucocorticosteroids and calcineurin inhibitors, combined with regular use of moisturizers. However, conventional treatments possess a certain degree of adverse effects, which raised concerns among the patients resulting in non-adherence to treatment. Hence, the modern use of moisturizers to improve barrier repair and function is of great value. One of the approaches includes incorporating bioactive ingredients with clinically proven therapeutic benefits into dermocosmetics emollient. The current evidence suggests that these dermocosmetics emollients aid in the improvement of the skin barrier and alleviate inflammation, pruritus and xerosis. We carried out a critical and comprehensive narrative review of the literature. Studies and trials focusing on moisturizers that include phytochemicals, natural moisturizing factors, essential fatty acids, endocannabinoids, and antioxidants were identified by searching electronic databases (PubMed and MEDLINE). We introduce the current knowledge on the roles of moisturizers in alleviating symptoms of atopic dermatitis. We then further summarize the science and rationale of the active ingredients in dermocosmetics and medical device emollients for treating atopic dermatitis. Finally, we highlight the limitations of the current evidence and future perspectives of cosmeceutical research on atopic dermatitis.

Biomarkers in asthma in the context of atopic dermatitis in young children

BACKGROUND

Diverse pathways stemming from a history of atopic dermatitis (AD) might modulate different biomarkers associated with the development of asthma. Biomarkers associated with AD and asthma separately have been investigated, but none have characterized a combined AD+asthma phenotype. We investigated the clinical and molecular characteristics associated with an AD+asthma phenotype compared with AD, asthma and controls.

METHODS

From a prospective birth cohort and the outpatient allergy clinic, we included four groups of 6-12-year-old children: (1) healthy controls (2) previous, current, or present AD without asthma, (3) previous, current, or present AD and current asthma and (4) current asthma without AD. We performed clinical examinations and interviews and measured serum IgE, natural moisturizing factors (NMF), and plasma cytokine levels.

RESULTS

We found an increased number of IgE sensitizations in AD+asthma, prominent after stratifying for food allergens (p < .05). Pro-Th₂ cytokines CCL18, TSLP, and Eotaxin-3 were elevated in AD+asthma, though not significantly higher than asthma, and elevated in asthma compared with controls. NMF levels were decreased in AD compared with asthma and control groups (p = .019, p < .001, respectively). NMF levels correlated negatively to sensitization (p = .026), though nonsignificant with only the patient groups.

CONCLUSION

Our results indicate that Th₂ cytokines and increased number of sensitizations are associated with AD + asthma phenotypes compared with AD alone and that skin barrier impairment as well as decreased airway epithelial integrity may play a role in sensitization and immune modulation. Our findings suggest candidate biomarkers that should be further explored for their functional roles and prognostic potential.