The Itch Severity Scale (ISS) in a Spanish version was assessed in 172 atopic dermatitis (AD) patients and 89 control patients under clinical practice conditions. The study was observational, prospective, multicenter and performed by 115 dermatologists in Spain. Correlations with the Modified Eczema Area and Severity Index (mEASI) and Dermatology Life Quality Index (DLQI) were measured. At baseline, the mean ISS score in unstable and stable patients was 8.8 and 6.9, respectively. The ISS correlated well with the DLQI (R = 0.72) and mEASI (R = 0.54) and the test-retest reliability was 0.61-0.66 in stable patients. The ISS effect size was 1.3-3.9 in those patients who improved. The ISS was a ...