A long-term evaluation of erythema and pigmentation induced by ultraviolet radiations of different wavelengths.
OBJECTIVE
The long-term reactions of human skin by different ultraviolet (UV)-wavebands were not reported. This study was to investigate a time course of erythema and pigmentation induced by UVA-1, broadband UVA (BBUVA), narrowband UVB (NBUVB) and broadband UVB (BBUVB).


METHODS
Ten volunteers participated in this study for 6 months. Four skin areas, from the back of each subject, were irradiated with two minimal erythema dose (MED) of four different UV wavelengths corresponding to UVA-1, BBUVA, NBUVB and BBUVB.


RESULTS
For both UVA-1 and BBUVA, erythema and pigmentation were most pronounced immediately and 1 h after exposure. Erythema rapidly diminished but pigmentation persisted throughout the study. For both NBUVB and BBUVB, test areas reacted with erythema of maximum intensity at 1 and 2 days, respectively. A maximum tanning was reached at 3-6 days for NBUVB and 4-7 days for BBUVB, and the return toward the original point was at 1 and 3 months, respectively.


CONCLUSIONS
Two MED of UVA produced far prolonged erythema and pigmentation than UVB. For UVA, UVA-1 and BBUVA showed similar intensity and time course of skin reaction. For UVB, erythema and pigmentation produced by NBUVB were milder in intensity and shorter in a time course than those by BBUVB.
Suh
K-S
KS
Department of Dermatology, Kosin University College of Medicine, Busan, South Korea.
Roh
H-J
HJ
Choi
S-Y
SY
Jeon
Y-S
YS
Doh
K-S
KS
Bae
J-H
JH
Kim
S-T
ST
D000328:Adult; D003116:Color; D004307:Dose-Response Relationship, Radiation; D004890:Erythema / Q000209:etiology*; D006801:Humans; D012880:Skin Pigmentation / Q000528:radiation effects*; D013997:Time Factors; D014466:Ultraviolet Rays