Histamine in human epidermal cells is induced by ultraviolet light injury

Human epidermal cell cultures were examined to determine whether they were capable of histamine release. Results of these studies indicated that keratinocytes contain and release significant amounts of histamine. In the skin of some individuals, histamine content was induced after ultraviolet B light injury, and 40% of subjects demonstrated high basal histamine levels. Mass spectrometric analysis of cell supernatants showed that the histamine was released into the extracellular environment. Such release may contribute to common itching or intensify the inflammatory response in vivo.