Evaluation of diagnostic criteria for atopic dermatitis: validity of the criteria of Williams et al. in a hospital-based setting

Background Surveys of the prevalence of atopic dermatitis (AD) have been ca rried out world-wide, but the results vary widely. The differences probably result from the use of different diagnostic criteria. Williams et al. prop osed minimum, simplified, diagnostic criteria that require no invasive test and are easy to use. Pilot studies in European countries showed their suit ability for implementation both in hospitals and in the community, and thei r high sensitivity and specificity. Objectives To evaluate the potential practical value of the criteria of Wil liams et al. in the Chinese population. Methods The criteria of Hanifin and Rajka (gold standard), Williams et al. and Kang and Tian were applied and compared in 111 patients with AD and 121 control subjects with other skin diseases in three out-patient centres in China. Results The criteria of Williams et al. showed a similar diagnostic efficie ncy to that of the gold standard, with the sensitivity, specificity and kap pa value reaching 95.50%, 97.52% and 0.93, respectively. No significant dif ference was found between the criteria of Williams et al. and those of Kang and Tian (chi (2) = 0.69, P > 0.05). 'Onset under the age of 2 years', a c riterion of Williams et al. could be used in subjects of any age. Conclusions The diagnostic efficiency of the criteria of Williams et al. wa s basically similar to those of Hanifin and Rajka and of Kang and Tian in o ur out-patient settings. However, those of Williams et al. were easier to a pply and required no invasive tests.