ABSTRACT
The study of skin biology has been undergoing a transformation over the past 20 years, owing to advances in technology that permit evaluation of parameters invisible to the naked eye. Many years ago, Kligman coined the term “invisible dermatoses” to emphasize that what appears visually normal can be quite abnormal under the skin surface (1). He even suggested that the future of dermatology would become so reliant on non-visual methods of diagnosis that the inability to see would not preclude one from a career in the field (2). Evolving techniques and instrumentation have facilitated the study of many of the skin’s physiological and biophysical properties, including water content, barrier properties, tensile strength, and elasticity, and even estimates of melanin, hemoglobin, and collagen. For those interested in the immune and inflammatory response of the skin, however, instrumental methods have been less useful.
