A Study of Efficacy of Chlorhexidine Scrub, ZnO Nanoparticles Socks and the Combination of Chlorhexidine Scrub and ZnO Nanoparticles Socks for Treatment of Pitted Keratolysis

Introduction Pitted keratolysis is a common skin disease, caused by various gram-positive bacteria including Corynebacterium species, Kytococcus sedentarius, Dermophilus congolensis and Actinomyces species. These bacteria create small tunnels in the stratum corneum, causing pitted lesions at plantar areas. This condition is frequent accompanied by feet malodor and is commonly found in young male adults, especially in soldiers, miners and athletes. The reported prevalence of pitted keratolysis among naval cadets in Thailand was 38.7%. Predisposing factors related to pitted keratolysis are pedal hyperhidrosis and prolonged feet occlusion. Although this condition is generally not painful, our previous study in 2018 revealed adversely affects patients' quality of life.

Regarding treatment modalities of pitted keratolysis, various medications and life-style modification have been recommended. Previous studies revealed efficacy of topical choices, including benzoyl peroxide gel, clindamycin-benzoyl peroxide gel, glycopyrrolate cream, erythromycin gel, clindamycin solution, chlorhexidine scrub and mupirocin ointment. Oral antibiotics and botulinum toxin injection were also beneficial in pitted keratolysis. As to life-style modification, wearing cotton socks and opened footwear, and proper hygiene, have also been suggested.

Zinc oxide (ZnO) has been demonstrated to exhibit antimicrobial activities against many microorganisms, such as Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa and fungal infections including dermatophytosis. It has been proposed that the mechanism is the generation of reactive oxygen species, such as hydrogen peroxide, on microorganism cell surfaces, thereby causing membrane dysfunction. The antimicrobial activities have been observed to vary with changes in the physical and chemical properties of ZnO, for instance, its particle size, porosity and specific surface area.

Nanobiotechnology , which is the integration of biotechnology and nanotechnology, is currently being used in drug delivery systems. The bactericidal efficacy of ZnO nanoparticles (ZnO-NPs) has been shown to improves with a decrease in their particle size. ZnO has also been shown to be is safe and compatible with human skin, which makes it a suitable additive for textiles. Research by Choopong and Sarayut established that ZnO-NP-coated socks exhibited antimicrobial activities against gram-positive (S. aureus) and gram-negative (Klebsiella pneumoniae) bacteria.

Objective This study aimed to study the efficacy of chlorhexidine scrub, zinc oxide nanoparticles (ZnO-NPs) socks and the combination of chlorhexidine scrub and ZnO-NPs socks in treatment of pitted keratolysis.