PIXE analysis of pathological skin with special reference to psoriasis and atopic dry skin

The nuclear microprobe is used for element analysis of human skin cross sections, providing new insight into the physiology of normal and pathological conditions. Special interest is focused on trace elements as they work as secondary messengers or regulatory substances. The distribution of ions in normal tissues serves as reference for pathological changes. Calcium (Ca2+) is assumed to take an important role in the differentiation process of the epidermis. This paper presents new data on elemental and trace elemental distributions in skin. Samples are prepared from skin biopsies obtained from patients with skin disorder and from individuals with no records of skin disorder serving as controls. Using the nuclear microprobe, both elemental maps and quantitative depth profiles are obtained. Previous findings of abnormal Fe distribution in psoriatic skin are confirmed, and new observations of altered Zn and Ca profiles in atopic skin are reported. The relation to possible physiological/biochemical mechanisms and apoptosis (''programmed cell death'') is discussed. The study is a part in a larger survey aiming at an understanding of the formation of a mature stratum corneum with a functional barrier, and its changed properties in cases of skin disorder.