Characterisation of Skin Microstructure Under Normal and Atrophied States

Skin dermatoses are a major health concern around the world, with heavy economic, social, and psychological burdens. Due to their chronic and incurable nature, they are serious diseases that cause physical pain in patients and reduced quality of life. Atopic dermatitis is the most common inflammatory skin disease with a prevalence of almost 20% in children and 10% in adults. Current therapies are designed to control the condition rather than cure it. Therefore, these therapies are lifelong and, when the disease is flaring, must be used intensively to achieve control. Despite the emergence of various therapies, topical corticosteroids (TCS) remains the gold standard therapy generally used as a first-line treatment. However, if used inappropriately, it can act like a double-edged sword. With the beneficial action of TCS comes the potential for undesirable effects, like skin thinning, especially when used long-term or excessively.

The objective of this study is to define the normal structural parameters for healthy skin in a diverse cohort, determine the effect of age, sex, and ethnicity and subsequently study how these values differ in clinically abnormal skin resulting from excessive or inappropriate use of topical corticosteroids (TCS). This will be achieved by using optical coherence tomography (OCT) to non-invasively image the skin. By undertaking this study, the investigators will gain real-world insight into the effects of long-term TCS use on the skin.