The skin barrier is a dynamic and multicomponent system that serves as the first line of protection for the body against pathogens, allergens, and transepidermal water loss. This narrative review, based on key insights from an international meeting on skin barrier function, provides a summary of the structural, chemical, microbial, and immunological components that form the skin barrier. The interplay between physical and chemical architecture of the stratum corneum in regulating barrier permeability and balancing immune responses is also discussed, particularly the roles of the acid mantle and ceramides in the extracellular lipid matrix. The interactions between the exposome, the skin and gut microbiomes, and the genome that influence skin barrier function are also considered. Finally, we review developmental and ethnic differences in skin barrier properties, which underscore the need for personalized approaches to skin care and disease management. Overall, the topics discussed in this narrative review highlight the importance of maintaining skin barrier integrity as a cornerstone of skin health, and present recent advances in our understanding of the complex interactions among skin barrier components, immune cells, and environmental factors. However, further research using innovative tools, such as the skin interactome, is essential for advancing targeted therapies and patient-centered care.
The skin barrier is a complex system composed of several functional layers (physical, chemical, microbiological, and immunological) that interact to protect the body from the environment while maintaining overall homeostasis. Proper functioning of the skin barrier can be disturbed by intrinsic as well as extrinsic factors, leading to the development of cutaneous disorders such as skin sensitivity, and inflammatory diseases such as atopic dermatitis. Skin moisturization is a key first-line strategy to maintain skin health and treat dermatological conditions associated with impaired skin barrier function. Beyond conventional topical therapies, alternative or complementary approaches have demonstrated potential in improving and restoring the function of the skin barrier. This narrative review summarizes key insights from proceedings of an international meeting on skin barrier function, during which various strategies for improving or restoring skin barrier integrity and relieving the potential consequences of skin barrier damage (e.g., dryness, irritation, and itching) were discussed. In particular, evidence presented supporting the effectiveness of nutraceuticals is described. This review also examines how using lasers to deliberately disrupt the skin barrier in a controlled manner can promote restoration via physiological skin repair mechanisms, as well as facilitate topical drug delivery. These findings underscore the need for continued research to allow for a more patient-centered approach to managing barrier dysfunction and optimizing skin care regimens.
Chronic inflammatory skin diseases, such as psoriasis, atopic dermatitis, and seborrheic dermatitis, are often linked to skin barrier dysfunction and altered immune responses. Effective management of these skin conditions can involve both medical and non-medical approaches, such as hydrotherapy. This review, based on a summary of conference proceedings from physicians and dermatologists, highlights the specific skin therapeutic properties of Avène thermal spring water (ATSW) and provides an overview of evidence supporting its clinical efficacy for managing dermatological conditions and post-procedural complications, whether used alone or as part of a combined regimen. Furthermore, this review summarizes cumulative clinical evidence and patient experiences highlighting how the 3-week hydrotherapy program offered at the Avène thermal center in France, incorporating ATSW and its derived products, can provide notable benefits for both adult and pediatric patients with chronic inflammatory skin diseases. The immediate and long-term benefits of this hydrotherapy program on skin symptoms and its positive impact on patient quality of life (QoL) are also discussed. Finally, to allow more patients to benefit from the properties of ATSW, suggestions proposed by dermatologists for the use of modified protocols involving in-office and at-home skincare routines, patient education, and the use of ATSW-derived products, are described. Overall, the findings gathered in this narrative review support the use of a combination of therapeutic and holistic approaches, along with follow-up skincare routines, as a valuable management strategy for improving the condition of the skin and QoL of patients affected by burdensome chronic inflammatory skin diseases.
Many external and internal factors can affect skin lipid synthesis and composition, which may impair skin barrier function, and potentially cause skin dryness, pruritus and other sensory symptoms. Pruritus, frequently associated with xerosis—particularly in inflammatory skin diseases, such as atopic dermatitis (AD)—is a commonly reported dermatological symptom in the general population. This narrative review, based on conference proceedings from clinicians and dermatologists, discusses the clinical and psychological impact of pruritus on individuals experiencing this subjective symptom. Starting with a summary of the key mechanisms involved in the itch–scratch cycle and signaling pathways shared with pain sensation, this review highlights the significant impact of chronic pruritus and associated symptoms, including sleep disturbances, on quality of life (QoL) and mental health. One of the main conclusions emerging from discussions between experts was that pruritus is a symptom with strong psychological features, which can easily become chronic under stressful conditions, and significantly affect patients’ daily life and well-being. Therefore, the psychological issues associated with chronic pruritus, such as anxiety and depression, must not be overlooked, and dermatologists should perform a general psychodermatological assessment of patients with chronic pruritus for effective management of their dermatological and underlying psychological symptoms according to current guidelines. Management options need to include supportive skincare products and medical approaches to relieve symptoms of skin barrier dysfunction and chronic inflammation, as well as holistic strategies to help manage the psychological consequences of chronic pruritus. If concomitant psychopathologies are diagnosed, tailored drug treatments should be considered on a case-by-case basis to adequately address them.
