Not all marketed skin cleansers' pH is optimal for atopic dermatitis

Background: The normally acidic skin pH changes in atopic dermatitis (AD) to alkaline, which contributes to the associated skin-barrier dysfunction. Hence, acidic cleansers would be preferred, but such information is scarce. Objective: Guiding health-care providers and patients on selecting skin cleansers with a pH optimal for AD. Methods: A total of 250 products were tested: 37 soaps (32 bars, 5 liquid) and 213 syndets (14 bars, 199 liquid); 10% solutions were tested for pH by using a pH meter; pH values 6.65-7.35 were considered neutral. Results: The pH of the tested skin cleansers varied widely (3.59-10.83). All 37 soaps were highly alkaline. In the 14 syndet bars, the pH was neutral in 6, alkaline in 8, and acidic in none. In the 199 syndet liquids, the pH was acidic in 84.9%, neutral in 11.1%, and alkaline in 4.0%. The product's pH was disclosed in none of the 37 soaps and in only 32 syndets (15%) , of which 9 bars were labeled "balanced," whose measured pH was neutral in 6 and alkaline in 3. Of the other 23 syndets, the labeled pH was referred to as "balanced" in 20 whose measured pH was neutral in 2 (6.80, 6.88) and acidic in 18 (3.59-6.59). The pH in the other three syndets was 4.25-6.00. Conclusion: All tested soaps had undesirable pH, whereas 84.9% of the liquid syndets were acidic (which is desirable) and 11.1% were neutral (which could be acceptable). Only 12.8% of the products disclosed the pH, an issue in need of improvement.