Glycerol 85% efficacy on atopic skin and its microbiome: a randomized controlled trial with clinical and bacteriological evaluation.

Treating atopic dermatitis (AD) is still a challenge. The staphylococcal skin load is known to aggravate AD. Narrow band ultraviolet B (NB-UVB) and glycerol in low concentration (20-40%) are established therapies for AD. NB-UVB has proven antimicrobial actions, while high concentration glycerol (85-100%) showed similar effects but has not been clinically tested. To evaluate the efficacy and tolerability of concentrated glycerol 85% compared to NB-UVB in patients with AD, as assessed by clinical improvement and reduction of staphylococcal colonization of the skin. 30 patients with mild to moderate AD were randomized into either NB-UVB or glycerol 85% group. Patients were treated for one month and followed for an additional month. Swabs were taken from the skin and nose to be cultured on mannitol-salt agar for Staphylococci and quantified to determine Colony Forming Units. Both groups showed statistically insignificant microbial changes and statistically significant clinical improvement after treatment. The results were comparable between both groups. Concentrated glycerol 85% is a cheap effective readily accessible alternative for phototherapy in patients with mild-moderate AD who cannot access the facility. Reduction of staphylococcal skin load seems to be involved, but its role is minimal.