Abstract: 【Abstract】 Objective To assess the specificity of white dermographism in atopic dermatitis （AD）, and to investigate the relationship between its duration and severity of AD. Methods From 1st to 30th March 2018, 78 patients with AD （AD group）, 100 patients with non-AD skin diseases （non-AD group） and 100 healthy controls without skin diseases （control group） were enrolled from Department of Dermatology, Wuhan No.1 Hospital. Dermographism test was conducted in each subject, and the subjects′response and duration of white dermographism were observed. Meanwhile, the severity of skin lesions of the AD patients was evaluated. Statistical analysis was carried out by using Chi-square test, analysis of variance and linear correlation analysis. Results Of the 78 patients in the AD group, 67 （85.90%） were positive for white dermographism, and the positive rate of white dermographism was significantly higher in the AD group than in the non-AD group （18.00% ［18/100］, χ2 = 80.97, P＜0.017） and control group （5.00% ［5/100］, χ2 = 119.05, P＜0.017）. Additionally, the positive rate of white dermographism was significantly higher in the non-AD group than in the control group （χ2 = 8.30, P＜0.017）. The average duration of white dermographism was 1.89 minutes in 30 patients with mild AD, 2.74 minutes in 25 patients with moderate AD, and 4.41 minutes in 12 patients with severe AD. There was a significant difference in the duration of white dermographism among the 3 AD subgroups （F = 64.588, P＜0.05）. Moreover, the severity of AD was positively correlated with the duration of white dermographism （r = 0.977, P = 0.136）. Conclusion White dermographism is a specific clinical manifestation of AD, and its duration is positively correlated with the severity of AD.

Key words: Dermatitis, atopic, Skin tests, White dermographism, Vascular response