The study of skin biology has been transformed over the past 20 years, largely owing to advances in measurement technologies that permit evaluation of parameters invisible to the naked eye. Years ago, the late Dr. Albert Kligman coined the term “invisible dermatoses” to emphasize that what appears visually normal can be quite abnormal under the skin surface [1]. He further suggested that the future of dermatology would become so reliant on nonvisual methods of diagnosis that traditional visual assessment techniques would likely be superseded by these noninvasive techniques [2].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 estimates of melanin, hemoglobin, and collagen. However, for those more interested in the immune and inammatory response of the skin, instrumental methods have been less useful.