Objective To evaluate the effect of salicylic acid on skin barrier function and the efficacy of salicylic acid combined with flumetasone ointment for the treatment of atopic dermatitis (AD).Methods Sixtyfour patients with AD (including 31 males and 33 females) aged 18 to 58 years were recruited into the present study.Four lesional areas of similar size and severity were selected at the similar body sites of both sides of each patient,and randomly classified into four groups to be topically treated with compound flumetasone ointment (containing 0.02％ flumetasone and 3％ salicylic acid,compound flumetasone group),flumetasone 0.02％ ointment (flumetasone group),salicylic acid 3％ ointment (salicylic acid group) and vehicle (control group),respectively;two normal skin areas were chosen from apparently normal skin on the similar body sites of both sides of each patient and topically treated with salicylic acid 3％ ointment (salicylic acid group) and vehicle (control group) respectively.All of these preparations were applied twice a day for 3 weeks.Transepidermal water loss (TEWL) was measured by a Tewameter MPA580 (Courage & Khazaka,Germany) at the baseline as well as on week 1,2 and 3 after initiation of treatment.Symptom and sign scores were evaluated before and after the treatment.Meanwhile,two normal skin areas were selected on bilateral forearm of 30 healthy controls and treated with 3％ salicylic acid ointment (salicylic acid group) and vehicle (control group) respectively twice a day for 3 weeks,and TEWL was measured before treatment as well as on week 1 and 3 after initiation of treatment.Results In the healthy controls,TEWL value showed no significant difference between the salicylic acid group and control group at any of these time points.As far as the lesional skin was concerned,no statistical difference was observed in TEWL value at the baseline between the four groups ((34.26 ± 20.82) vs.(33.02 ±16.71) vs.(34.16 ± 18.03) vs.(33.81 ± 17.11) g· m-2· h-1,P ＞ 0.05),but significant difference was noted after treatment (repeated measurement data analysis of variance,F =39.57,P ＜0.01),with the TEWL value being (22.38 ± 16.16),(17.04 ± 12.74),and (15.34 ± 13.13) g·m-2·h-1 respectively in the compound flumetasone group on week 1,2 and 3,(24.63 ± 17.08),(20.37 ± 9.53),(19.06 ± 9.17) g·m-2·h-1 respectively in the flumetasone group,(26.49 ± 8.59),(21.91 ± 8.46),(21.20 ± 9.38) g·m-2·h-1 respectively in the salicylic acid group,and (29.80 ± 12.48),(26.16 ± 8.31),(25.52 ± 6.05) g·m-2·h-1 respectively in the control group.In detail,the decrease in TEWL value was stronger in the compound flumetasone group than in the flumetasone group on week 1,2,and 3 (all P ＜0.05),in the salicylic acid group than in the control group (P ＜0.05 or 0.01),but similar between the flumetasone group and salicylic acid group.In non-lesional skin,the salicylic acid group showed a more intense decrease in TEWL value compared with the control group on week 2 and 3 (both P ＜0.05).Both the cure rate and response rate were significantly higher in the compound flumetasone group than in the flumetasone group (53.1％ vs.34.4％,x2 =4.57,P＜0.05;83.1％ vs.64.1％,x2 =6.90,P＜0.01).Conclusions The salicylic acid 3％ ointment shows a reparative effect on skin barrier in patients with AD,and the compound flumetasone ointment is superior to the flumetasone ointment in the treatment of AD.