title: A comparison of the ultraviolet B-induced erythemal response of back and buttock skin.
abstract: Thirty-six subjects (dermatology patients and normal volunteers) were phototested on back and buttock skin to determine their erythemal response to a geometrically increasing series of doses of ultraviolet B (UVB) radiation. The minimal erythema doses (MED) were recorded at 24 h post-irradiation and dose-response curves were constructed. A significant difference in MED was found between the 2 sites, with a higher value for buttock skin (median 38 mJ/cm2) than for the back (median 25 mJ/cm2). The slopes of response for the 2 sites were, however, found to be comparable, and there was no correlation between the slope of dose response and sun-reactive skin type at either site. Buttock skin, representing the constitutional skin colour, may provide a useful site for phototesting, especially in otherwise tanned individuals, providing that full dose-response curves are analysed.
authors: Department of Medicine, Royal Liverpool University Hospital, United Kingdom.
authors: L E
authors: LE
authors: Rhodes
authors: P S
authors: PS
authors: Friedmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001415:Back; D002081:Buttocks; D004307:Dose-Response Relationship, Radiation; D004890:Erythema / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000528:radiation effects*; D012880:Skin Pigmentation / Q000528:radiation effects; D012882:Skin Tests; D014466:Ultraviolet Rays