The assessment of post mortem structural changes in the human epidermis.

The structure of epidermis and appearance of keratinocytes is described in intact skin specimens from human corpses stored after death under refrigeration. Two groups of alterations can be identified depending on the epidermal layer. In the spinous layer, the cells are characterized by crescent-shaped nuclei surrounded by a hollow area. The number of such cells increases significantly each day during the first 8 days post mortem (dpm), and their frequencies follow respective regression equations, so as to enable the post mortem time estimation with one day accuracy. In the basal layer, distorted, balloon-shaped cells with pycnotic nuclei appear, which with the lapse of time are forming groups, and eventually the epidermis in those places separates from the dermis. The presence of both described changes seems to indicate whether the skin sample was obtained from the living organism or after the death.