 If at moderate doses “pure” apoptosis does not cause an inflammatory reaction, then at sufficiently large (but lower than superlethal) doses, an inflammatory reaction arises due to pro-inflammatory apoptosis, which leads to the appearance of “fast” erythema for UV irradiated skin keratinocytes.Kinetic of “fast” erythema is much faster by the time of development of UV erythema caused by necrosis of UV damaged keratinocytes [6].The most erythemogenic is UVB (UVB, 280 - 320 nanometers) the spectral range of UVR, since radiation in this range is less absorbed by the outer layers of the skin, which allows UVB radiation, in contrast to UVC (UVC, 200 - 280 nm), to reach more deep layers skin and act on keratinocytes of the deep-lying basal layer of the epidermis of the skin.