When vitiligo patients use the home narrow spectrum medium wave UVB phototherapy instrument for treatment by themselves without the guidance of a phototherapist, they need to pay attention to determine the exposure time, including three parts: the frequency and total number of light exposure, the starting exposure time and the incremental exposure time.
I, the frequency and total number of light usually UVB phototherapy frequency of 2-3 times a week, or every other day. Once a day is not recommended. Due to the lack of long-term follow-up data, only from the clinician’s observation, there is no limit to the total number of UVB phototherapy. A foreign review reported that UVB phototherapy for 33 – 93 months did not show patients with suspicious skin lesions or non-melanoma skin cancer (NMSC). The increased odds of skin cancer were not statistically significant compared to the general population. This indicates that UVB phototherapy can be a safe and effective treatment method for vitiligo patients that can be used for a long time.
The first time you are going to be able to get a good deal on your own, you are going to be able to get a good deal on your own. This is directly related to the irradiation dose. The medical profession according to the type of disease, the user’s skin type, etc. to determine the starting irradiation dose —- our population skin type is mostly III to Ⅳ, vitiligo patients UVB phototherapy starting irradiation dose of 0.2J/cm2 (Joules / per square centimeter), PUVA therapy starting irradiation dose of 1.0J/cm2. Determine the starting irradiation dose, according to the base of the UV light therapy instrument After determining the starting irradiation dose, the corresponding starting irradiation time can be determined according to the irradiation intensity value of the machine marked on the base of the ultraviolet light therapy instrument and the “irradiation time calculation method” in the appendix of the instruction manual of the light therapy instrument, or check the “irradiation dose, intensity and time reference table”. To “calculation method” for example: if you buy the base of the phototherapy instrument marked irradiation intensity of 11.00mw/cm2 (milliwatt/cm2), and the usual vitiligo starting irradiation dose of 0.2J/cm2, converted to 200mJ/cm2 (mJ//cm2), set into the calculation formula: irradiation Time = irradiation dose / irradiation intensity, that is, the starting irradiation time = 200mJ/cm2 / 11.00mw/cm2 = 18.2s (seconds). Will not be calculated, the starting irradiation time can be set at 20 seconds.
Third, incremental irradiation time After the starting irradiation time is determined and the first phototherapy, not the subsequent irradiation time is unchanged. It is important to pay attention to the revision of the second, third, until the Nth irradiation time. In other words, whether or not the duration of each successive phototherapy session should be increased, and the percentage of increase, should be determined according to the skin response at the phototherapy site.
The principles are: 1. If slight erythema appears after the previous phototherapy and has subsided at the time of this phototherapy, the time should be increased by 10% on top of the previous exposure time; 2. If significant erythema appears after the previous phototherapy and has not subsided at the time of this phototherapy, the previous exposure time should be maintained; 3. If the erythema is still severe and accompanied by pain or even blistering at the time of this phototherapy, the phototherapy should be suspended; 4. There is no phototherapy reaction after the previous irradiation, then you can increase the previous irradiation time by 20%. For example, if your previous irradiation time is 18 seconds and there is no treatment response after irradiation, your next irradiation time should be increased to 22 seconds.