壓力代表著一種可破壞生物體內平衡的力量，他可以從外來，亦可以內部發出。
一般的壓力我們是可以應付的。但是，如果緊張情緒持續，有可能導致我們精神疲憊，困擾，疾病，甚至會出現慢性皮膚問題。
心理皮膚病學研究了心理與皮膚之間的相互作用。多項研究亦發現，約25-33％的皮膚疾病是由於心理因素引起的。脫髮，玫瑰痤瘡，瘙癢和特應性皮炎主要是由情緒引起的。
當我們承受壓力時，皮質醇水平會提高。皮質醇會在角質層中積累，改變促炎和抗炎細胞因子（細胞之間的信使）之間的平衡，從而破壞皮膚屏障功能。這可能會導致發炎，刺激或瘙癢。
在傳統醫學中，我們可能需要分別尋求心理學家和皮膚醫生意見及治療。現今我們對大腦-皮膚軸認知更多，心理皮膚病學便能更有效地幫助我們解決由情緒引起的皮膚問題。
Stress represents an internal and external force that threatens to disrupt the homeostatic balance of an organism. General stress is manageable. However, if one constantly faces high level of tension, chronic skin problem could be developed because chronicity could lead to exhaustion, distress, and disease or flare-up of dermatoses.
Psychodermatology has studied the interaction between the mind and skin. It has been estimated in various studies that about 25-33% of skin diseases are due to psychological factors. It is also found that alopecia, rosacea, pruritus and atopic dermatitis are mostly triggered by emotion.
When we are under pressure, the cortisol level will be higher. Cortisol does accumulate in stratum corneum. It changes the balance between pro- and anti-inflammation cytokines (the messenger between cells) to disrupt the skin barrier function. This then could cause inflammation, irritation, or itching.
In conventional medicine, the mental and skin health issues would have to be addressed separately by psychologist and dermatologist. However, as we have more knowledge about the brain-skin axis, psychodermatorology could be more efficient and effective to address stress-related skin problems.
Reference:
Psychodermatology: When the Mind and Skin Interact https://www.psychiatrictimes.com/view/psychodermatology-when-mind-and-skin-interact
Psychological Stress Deteriorates Skin Barrier Function by Activating 11β-Hydroxysteroid Dehydrogenase 1 and the HPA Axis https://www.nature.com/articles/s41598-018-24653-z