Effect of topical nonsteroidal anti-inflammatory drugs and corticosteroids on ultraviolet ray-induced erythema

Abstract

Objective To observe the suppressing effect of topical nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids on ultraviolet ray (UV)-induced erythema.Methods A solar simulator and an UV phototherapy device were used as light sources,respectively.Erythema reaction was induced on the back skin of 30 healthy volunteers by 1,2 and 3 minimal erythema doses (MED) of irradiation.Five preparations including butyl flufenamate 2.5％ ointment,butyl flufenamate 5％ ointment,the base of butyl flufenamate ointment,halometasone ointment,and diclofenac 1％ ointment,were applied to the irradiation sites respectively half an hour before or immediately after the irradiation.One irradiation site remained untreated and served as the control.The degree of erythema was evaluated by a chromameter at 4,24,and 48 hours after the irradiation.Intragroup and intergroup comparisons were done by t test and analysis of variance,respectively.Results When applied half an hour before solar-simulated irradiation,both 2.5％ and 5％ butyl flufenamate ointment totally suppressed the erythema reaction induced by 1-3 MED of UV irradiation,with no significant increase in erythema index at all the three time points after irradiation (all P ＞ 0.05); diclofenac 1％ only inhibited the erythema induced by 1 MED of UV irradiation at 4 and 48 hours,with no difference observed in erythema index between the baseline and these time points after irradiation; however,halometasone significantly aggravated the erythema reaction (P ＜ 0.05).Neither NSAIDs nor corticosteroids applied immediately after solar-simulated irradiation showed statistical effect on the degree of UV-induced erythema.When applied immediately after irradiation using the phototherapy device,butyl flufenamate 2.5％ ointment,butyl flufenamate 5％ ointment and halometasone ointment all induced a significant reduction in erythema reaction at 4 hours after 1 MED of irradiation (all P ＜ 0.05),and diclofenac caused a statistical decrease in erythema reaction at all the time points after 1-3 MED of irradiation (all P ＜0.05).Conclusions Topical use of butyl flufenamate before UV irradiation can effectively inhibit erythema reaction induced by 1-3 MED of irradiation.When applied immediately after irradiation,diclofenac shows the strongest erythema-suppressive effect,followed sequentially by butyl flufenamate and halometasone. Key words: Flufenamic acid; Glucocorticoids; Ultraviolet rays; Erythema