title: A long-term evaluation of erythema and pigmentation induced by ultraviolet radiations of different wavelengths.
abstract: 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.
authors: Department of Dermatology, Kosin University College of Medicine, Busan, South Korea.
authors: K-S
authors: KS
authors: Suh
authors: H-J
authors: HJ
authors: Roh
authors: S-Y
authors: SY
authors: Choi
authors: Y-S
authors: YS
authors: Jeon
authors: K-S
authors: KS
authors: Doh
authors: J-H
authors: JH
authors: Bae
authors: S-T
authors: ST
authors: Kim
mesh_terms: 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