Skin care by washing with water is not inferior to washing with a cleanser in children with atopic dermatitis in remission in summer: WASH study.

BACKGROUND: Washing with water is not inferior to washing with soaps and detergents in children with atopic dermatitis (AD) in remission during the fall-winter seasons. We investigated whether this finding varies during summer based on the type of cleanser (soaps and detergents). METHODS: This evaluator-blinded, pragmatic, randomized, and non-inferiority study enrolled patients with AD whose eczema was controlled following regular steroid ointment application 2 days/week. For 8 ± 4 weeks, participants washed their upper and lower limbs with a cleanser on one side and with water alone on the other. Each participant chose either a weakly alkaline soap or an acidic detergent. The primary outcome was the Eczema Area and Severity Index (EASI) score at week 8 ± 4. RESULTS: The data of 43 of the 47 registered participants were analyzed. The median patient age was 44 (23-99) months; 28 and 15 participants chose weakly alkaline and acidic cleansers, respectively. At week 8 ± 4, EASI scores of the water and cleanser sides were 0.00 (0.00-0.40) and 0.15 (0.00-0.40), respectively (p = 0.74). The difference between both sides was 0.00 (-0.07 to 0.14); the limits of the 95 % confidence interval did not reach the pre-specified non-inferiority margin. No difference was observed in the median Patient-Oriented Eczema Measure score, number of additional steroid ointment applications, and occurrences of skin infections. There were no differences between the cleanser types in any of the results. CONCLUSIONS: We demonstrated that washing with water was not inferior to that with a cleanser in patients with AD in the maintenance phase during summer, regardless of the type of cleanser.

Washing with water alone versus soap in maintaining remission of eczema.

BACKGROUND: There is no consensus on the use of soap in skin care for atopic dermatitis in Japan. Thus, this study aimed to evaluate the efficacy of soap to maintain eczema remission in atopic dermatitis patients during the fall-winter period in Japan. METHODS: This assessor-blinded, pragmatic randomized, non-inferiority study enrolled atopic dermatitis patients whose eczema was controlled by regular steroid ointment application less than or equal to 2 days / week (tacrolimus ointment was permitted). For 8 ± 3 weeks, participants washed their upper and lower limbs on one side with soap (soap side) and on the other side with water alone (water side). The primary outcome was an Eczema Area and Severity Index score at week 8 ± 3. RESULTS: Twenty-nine participants were analyzed. The Eczema Area and Severity Index scores at week 8 ± 3 of the water and soap sides were 0.0 (0.0-0.4) and 0.0 (0.0-0.4), respectively (P = 0.18). The difference between both sides was -0.02 (-0.11-0.08), and the limits of the 95% confidence interval did not reach the prespecified non-inferiority margin. The average Patient-Oriented Eczema Measure score was 1.27 ± 1.7 and 1.32 ± 1.8 for the water and soap sides, respectively (P = 0.92). The total number of additional steroid ointment applications was four (0-20) times and six (0-23) times, respectively (P = 0.98). Participants were categorized according to self-assessments of the usefulness of soap, with 2, 24, and 3 participants in the water-effective, invariant, and soap-effective groups, respectively. CONCLUSIONS: For children with controlled atopic dermatitis, washing with water alone was not inferior to washing with soap for maintaining remission of eczema during the fall-winter period in Japan.