Effects of sunscreen on human skin's ultraviolet radiation tolerance.
OBJECTIVE
To observe the alteration ultraviolet radiation (UVR) of skin's tolerance after its exposure to the small dose of UVR under the protection of sunscreen.


METHODS
Eleven subjects who applied sunscreen were exposed to 0.75 dose minimal persistent pigment darkening (MPPD) and minimal erythema dose (MED) by the Phototherapy Unit for 4 weeks. Each week their MPPDs and MEDs were measured by solar simulator. Meanwhile, SPECTCOLOMETER® and VISIOSCAN VC98® were used to detect the test areas and control areas.


RESULTS
The values of MPPD and MED increased significantly after the exposure to UVR. But there were no visible changes on the surface of skin's texture.


CONCLUSIONS
With the protection of sunscreen, the UVR tolerance of skin was greatly increased after the skin's exposure to the small dose UV.
Skin & Cosmetic Research Department, Shanghai Skin Disease Hospital, Shanghai, China.
Chao
C
Yuan
Xue-min
XM
Wang
Yi-mei
YM
Tan
Li-jie
LJ
Yang
Yin-fen
YF
Lin
Pei-lan
PL
Wu
D000328:Adult; D004890:Erythema; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000187:drug effects*; D012867:Skin / Q000187:drug effects* / Q000528:radiation effects*; D012880:Skin Pigmentation / Q000187:drug effects / Q000528:radiation effects; D013473:Sunscreening Agents / Q000494:pharmacology*; D014466:Ultraviolet Rays
D013473:Sunscreening Agents