Reactive changes in human epidermis following simple occlusion with water

Reactive changes produced in human epidermis by occlusion with water for 24 or 48 h were studied. A focally widened intercellular space was common. Several, often pronounced, reactive events were observed in the Langerhans cell system, whereas the keratinocytes and the melanocytes seemed unaffected. The reactive events showed a scattered distribution and were revealed only by electron microscopic analysis of extensive section series. It seems that, among epidermal cells, the Langerhans cells are the most susceptible and most easily alerted by an exogenous challenge.