Effectiveness and safety of zinc oxide nanoparticle‐coated socks compared to uncoated socks for the prevention of pitted keratolysis: a double‐blinded, randomized, controlled trial study

Abstract

Pitted keratolysis (PK) and bromodosis have negative impacts on the quality of life especially for military personnel. The antibacterial efficacy and safety of zinc oxide nanoparticles (ZnO-NPs) make them a suitable additive for textiles. We aim to establish the ability of ZnO-NP-coated socks to prevent PK and bromodosis in a real-life setting. A double-blinded, randomized, controlled trial was conducted in January 2019. Naval cadets assigned to a 14-day field training course were randomly allocated to either a ZnO-NP-coated or an uncoated-sock group. They completed questionnaires evaluating behavioral risk factors and self-assessed foot odor levels using a visual analogue scale (VAS); intervention-blinded dermatologists also performed foot examinations. They reassessed their odor levels and had their feet re-examined upon completion of the training course. The 148 cadets enrolled for the study were allocated to two groups of 74 each. The ZnO-NP-coated sock participants demonstrated significantly less PK development than uncoated socks (P=0.05). There was a reduction of the foot odor levels in both groups, as measured by the VAS, without statistical difference. However, the uncoated sock group experienced more foot odor with a significantly greater negative effect on their daily lives (P=0.04) than the ZnO-NP-coated sock group. ZnO-NP-coated socks proved their efficacy in inhibiting the development of PK for military personnel.