UVB is divided into long wave UVB, medium wave UVB and short wave UVB according to different wavelengths.
The sensitivity of different parts of the human skin to ultraviolet light varies, and the difference between different individuals is also large, affected by a variety of factors, the general human skin is more sensitive to medium-wave ultraviolet light, so the clinical in vitiligo for medium-wave ultraviolet radiation treatment before, it is best to determine the patient’s light sensitivity. It is called basic erythema amount, and when the irradiation intensity is more than 5 biological doses, the skin erythema is obvious and blisters can appear, which is called super erythema amount.
The intensity of irradiation for basic erythema amount in clinical application of UV treatment for vitiligo, because the biological effect of sub erythema amount is slight and cannot achieve better re-coloring effect of white spots, while super erythema amount can cause serious adverse reactions and even cause the expansion of white spot area or the appearance of new lesions.
Therefore, when applying UV treatment for vitiligo, the intensity and time of irradiation should be adjusted in time according to the sensitivity of different individuals to UV and skin reaction.