title: Quantitative studies on UVA-induced erythema in human skin.
abstract: The erythemal response of normal human skin to UVA and UVB radiation was measured objectively using a reflectance instrument in seven subjects, and a laser Doppler velocimeter in two subjects. UVA radiation was produced using a newly-developed high-intensity UVA lamp. The slope of the log dose-erythemal response curve for UVA at 24 h after irradiation was found not to differ significantly from that for UVB. The time course of UVA erythema was biphasic; erythema was present immediately after irradiation, fell to a minimum at about 4 h and then rose to a broad plateau between 6 and 24 h. The intensity of the early phase was dose-rate dependent, whereas that in the later phase depended on dose only.
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004890:Erythema / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D012867:Skin / Q000098:blood supply / Q000528:radiation effects*; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects*