Comparison of Fungal Culture Positivity using Surgical Blade and Emery Board in Onychomycosis Patients

Kwon, Won Joo; Kim, Min Seok; Cho, Eun Byul; Park, Eun Joo; Kim, Kwang Ho; Kim, Kwang Joong

Abstract

BACKGROUND
Usually, we did the fungus culture by collecting nail samples using a surgical blade, but this procedure showed low positive culture rate. An emery board is a tool used to gently grind down and shape the edges of nails.
OBJECTIVE
The aim of this study is to compare positive culture rates of nail sampling techniques in diagnosis of onychomycosis using surgical blade and emery board.
METHODS
We collected and assessed data of 49 patients in total, with chief complaints of nail problem, and showed positive results in KOH smear. Fungus culture was performed twice in each patient, both by scraping nail with surgical blades and grinding nail piece with emery board. After 4 weeks from culture, we compared positive culture rates of two nail sampling techniques.
RESULTS
In 49 patients, 16 patients were male and the other 33 were female, with average age of 51.4 years. When classified by morphological type, there were 45 cases of distal lateral subungual onychomycosis (DLSO) and 4 cases of white superficial onychomycosis (WSO). Culture using emery board produced 18 positive results (36.7%) out of 49 patients, and that using surgical blade produced 9 positive results (18.4%); the difference were statistically significant. In other words, nail sampling using emery board rather than surgical blade resulted in higher positive culture rate.
CONCLUSION
Therefore, emery board can be used as a useful device for diagnosis and identification of causative fungi in onychomycosis in clinical practice and a method to enhance positive rates of cultures.