A Comparison of Minimal Erythema Dose and Minimal Melanogenic Dose Induced by Ultraviolet A-1, Broad Band Ultraviolet A, Narrow Band Ultraviolet B, and Broad Band Ultraviolet B

Jeon, Young Seung; Suh, Kee Suck; Kim, Sang Tae

Abstract

BACKGROUND
The erythemal and tanning responses of the skin to UV radiations, which are used as diagnostic phototest and guideline of phototherapy, are different, depending on the races and light sources. Minimal erythema dose (MED), barely perceptible minimal melanogenic dose (MMDb) and well-defined border minimal melanogenic dose (minimal melanogenic dose, MMDw) of broad band UVA (BBUVA), UVA-1, broad band UVB (BBUVB), and narrow band UVB (NBUVB) have not yet been reported. Therefore this study was undertaken to measure the MED, MMDb and MMDw of BBUVA, UVA-1, BBUVB and NBUVB radiation. METHODS: Ten healthy Korean volunteers were recruited. Four volnuteers were Fizpatrick skin type III and six were IV. In this study, a metal halide lamp (SUPUVASUN 3000) was used as the BBUVA and UVA-1 light sources, a fluorescent blacklight lamp (Philips TL 20W/12 UVB lamp) as the BBUVB, and a fluorescent blacklight lamp (Philips TL 20W/01) as the NBUVB. The MED, MMDb and MMDw of the skin were visually assessed 24 hours and 7 days after irradiation. RESULTS: 1. BBUVA MED, MMDb and MMDw of BBUVA were 53.0+/-8.2J/cm2 (mean+/-S.D.), 38.0+/-7.8J/cm2, and 51.0+/-8.7J/cm2, respectively. MED, MMDb and MMDw of BBUVA in Fitzpatrick skin phototype III (FST III) were 50.0+/-8.1J/cm2, 35.0+/-5.7J/cm2, and 47.5+/-5.0J/cm2, respectively. MED, MMDb and MMDw of BBUVA in FST IV were 55.0+/-8.3J/cm2, 40.0+/-8.9J/cm2, and 53.3+/-10.3J/cm2, respectively. 2. UVA-1 MED, MMDb and MMDw of BBUVA were 58.0+/-9.1J/cm2, 40.0+/-4.7J/cm2, and 54.0+/-9.6J/cm2, respectively. MED, MMDb and MMDw of BBUVA in FST III were 52.5+/-9.5J/cm2, 37.5+/-5.0J/cm2, and 52.5+/-12.5J/cm2, respectively. MED, MMDb and MMDw of BBUVA in FST IV were 61.6+/-7.5J/cm2, 41.6+/-4.0J/cm2, and 55.0+/-8.3J/cm2, respectively. 3. BBUVB MED, MMDb and MMDw of BBUVA were 52.0+/-12.2mJ/cm2, 57.0+/-10.5mJ/cm2, and 69.0+/-11.0mJ/cm2, respectively. MED, MMDb and MMDw of BBUVA in FST III were 42.5+/-5.0mJ/cm2, 55.0+/-5.7mJ/cm2, and 67.5+/-9.5mJ/cm2, respectively. MED, MMDb and MMDw of BBUVA in FST IV were 58.3+/-11.6mJ/cm2, 58.3+/-13.2mJ/cm2, and 70.0+/-12.6mJ/cm2, respectively. 4. NBUVB MED, MMDb and MMDw of BBUVA were 680+/-131.6mJ/cm2, 770+/-105.9mJ/cm2, and 910+/-99.4mJ/cm2, respectively. MED, MMDb and MMDw of BBUVA in FST III were 650+/-129.1mJ/cm2, 725+/-125.8mJ/cm2, and 850+/-100.0mJ/cm2, respectively. MED, MMDb and MMDw of BBUVA in FST IV were 700+/-141.4mJ/cm2, 800+/-89.4mJ/cm2, and 950+/-83.6mJ/cm2, respectively. CONCLUSION: The MMDb and MMDw induced by BBUVA and UVA-1 were less than MED induced by BBUVA and UVA-1, but MED induced by BBUVB and NBUVB was less than MMDb and MMDw induced by BBUVB and NBUVB. These results suggest that the erythemal and tanning response of the skin to UV radiations are different, depending on the UV wave length.