DUCT DISRUPTION, A NEW EXPLANATION OF MILIARIA

From argument and a few personal observations, the hypothesis has crys tallised that the miliaria commonly occurring in unacclimatised Caucas ians visiting hot climates is caused by exposure to ultraviolet irradi ation, by an effect on the cells of the upper epidermis, which eventua lly allows a split to develop between them and the new stratum corneum that grows up beneath, into which sweat from the disrupted ducts can collect as microcysts. This dehiscence is the probable explanation of sunburn peeling and photo-onycholysis. It is concluded that duct disru ption, not blockage or dysfunction, is the immediate cause of the mili arias.