The impact of stress on epidermal barrier function: an evidence‐based review. (1st December 2019) - Maarouf, M.
Summary: Background: The epidermal barrier functions to limit skin infection and inflammation by inhibiting irritant and immunogen invasion. Abundant evidence suggests that psychological stress stemming from crowding, isolation, nicotine smoking, insomnia, mental arithmetic tasks, physical pain, real‐life stressors (examinations and marital strain) and lack of positive personality traits may impart both acute and chronic epidermal dysfunction. Objectives: To review the relationship between stress and epidermal barrier dysfunction. Methods: A review of the PubMed and Embase databases was conducted to identify all English‐language case–control, cross‐sectional and randomized control trials that have reported the effect of stress on epidermal barrier function. The authors' conclusions are based on the available evidence from 21 studies that met the inclusion and exclusion criteria. Results: Psychological stressors upregulate the hypothalamic–pituitary–adrenal axis to stimulate local and systemic stress hormone production. This ultimately leads to aberrant barrier dysfunction, characterized by decreased epidermal lipid and structural protein production, decreased stratum corneum hydration and increased transepidermal water loss. Conclusions: This evidence‐based review explores the adverse effects of psychological stressors on epidermal barrier function. Future investigations using more real‐life stressors are needed to elucidate further their impact on skin physiology and identify practical stress‐relieving therapies that minimize and restore epidermal barrier dysfunction, particularly in at‐risk populations. What's already known about this topic? The literature reports the negative effect of stress on prolonged wound healing. Less is known about the relationship between stress and epidermal barrier dysfunction, a chronic, superficial wound involving the upper epidermal layers. What does this study add? Psychological stressors impact epidermal barrier function by activating the hypothalamic–pituitary–adrenal axis to stimulate local and systemic stress hormone production. Stress hormones negatively affect the epidermal barrier by decreasing epidermal lipids and structural proteins, decreasing stratum corneum hydration and increasing transepidermal water loss. Identification of such stressors can promote stress‐avoidance and stress‐reduction behaviours that protect epidermal barrier function and prevent certain dermatological conditions.