The condition of the skin, whether it is normal, dry, eczematous, etc., reflects its physiology/pathophysiology. Only during the past three decades has it been possible to probe the physiology of human skin, and this has been achieved through the means of particle probes. The electron and the proton probe both rely on the production of secondary x-ray quanta emission, which allows identification as well as quantification of elements. Since there exists no wellestablished model to substitute for human skin in experimental approaches to clinically normal and pathological skin conditions, this chapter is devoted to the study of element and particularly trace element distributions in normal and pathological human skin. It is interesting to note that the development of modern medicine from the moment of the discovery of x-rays has been closely linked to the development of physics. Almost immediately after his discovery of x-rays in December 1895, Konrad Röntgen made an image of his left hand carrying a finger ring. From a historical point of view, this can truly be regarded as the first clinical x-ray image. It is a fact that this image had a tremendous impact on the contemporary medical body, and the clinical applications of the method were greeted with great enthusiasm among medical doctors. It became obvious that the density of the material was related to the degree of x-ray absorption, that is, the bones were seen easily against the background of soft tissue. In clinical practice this resulted in the invention of contrast media which allowed, for example, the intestinal system to be imaged with a fair amount of detail.