The effect of topical indomethacin on ultraviolet-radiation-induced erythema.
Indomethacin inhibits UVB erythema but is thought not to influence UVA erythema. We have examined the wavelength dependence of the effect of indomethacin on ultraviolet radiation (UVR) erythema. Duplicate sites on the back were irradiated with a series of doses at 300 and 320 nm, or single doses at 330, 340, 350 or 370 nm. Indomethacin 1% was applied to sites on one side of the back after irradiation, occluded for 2h and erythema measured at 24h with a reflectance instrument. Indomethacin inhibited 300 and 320 nm (UVB) erythema, had no effect at 330 and 340 nm (UVA2), but augmented 350 and 370 nm (UVA1) erythema. There appears to be a varied response of UVR erythema to cyclo-oxygenase inhibition at different wavelengths across the UVR spectrum. This mechanism may be deranged in certain photosensitive disorders.
Department of Dermatology, Royal Victoria Infirmary, Newcastle upon Tyne, U.K.
S H
SH
Ibbotson
B L
BL
Diffey
P M
PM
Farr
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004307:Dose-Response Relationship, Radiation; D004890:Erythema / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control; D014466:Ultraviolet Rays / Q000009:adverse effects* / Q000145:classification
D000894:Anti-Inflammatory Agents, Non-Steroidal; D016861:Cyclooxygenase Inhibitors; D007213:Indomethacin