The Significance of KONCPA Test in Onychomycosis

Kwon, Yoon Hee; Cho, Baik Kee

Abstract

BACKGROUND: It has been reported that KONCPA(KOH+Nail clipping+PAS reaction) test might be a useful complementary method with a high positive rate and an exellent view for making the diagnosis of onychomycosis.
OBJECTIVE
KONCPA test, Onyehomycosis This study was aimed to know whether KONCPA test would increase the diagnostic sensitivity of onychomycosis, and agree with the findings of fungus culture and whether KONCPA finding would be of help in diagnosing the causative fungi even in case that KOH smear and fungus culture fail to identify the causative fungi.
METHODS
Using 95 onychomycotic nail samples obtained from 87 patients, the KONCPA findings were compared with those of KOH smear and fungus culture.
RESULTS
The results were as follows ; 1. The positive rates for dtecting the causative fungi from KOH srnear, fungus culture and KONCPA test were 779%, 45.3% and 95.8% respectively. The time required for KONCPA test, showing the highest positive rate, was only about 2 to 3 hours. 2. The fungus culture identified the causative fungi from 43 samples, of which dermatophytes were found in 31 samples(72.1%), Candida spp. in 5 samples(11.6%) and molds in 7 samples(16. 3%). KOH smear revealed the causative fungi in 63 samples : dermatophytes 56(88.9%), Candida spp. 4(6.3%) and molds 3(4.8%). KONCPA yielded the highest positivity by detecting the pathogenic fungi in 86 samples(95.8%): dermatophytes 60(69.8%), Candida spp. 8(9.3%), molds 10 (11.6%) and mixed infections 8(9.3%). 3. Compared with the results of fungus culture, 3 groups of fungi showed morphologic differences on KONCPA test: dermatophyte showing septated long and thin hyphae and a few arthrospores, Candida sp. showing blastospores and/or grape-like clusters of regular spores and pseudohyphae, and mold showing irregular hyphae with variable width and aggregates of irregular spores. 4. Of the 52 samples which were negative in fungus culture, 33(63.5%) showed findings of dermatophyte, 2(3.8% ) of Candida sp., 2(3.8% ) of mold and the remaining 11 samples(21.2% ) were negative on KOH smear, Of these 52 samples, KONCPA diagnosed 34(65.4%) to be dermatophytes, 6(11.5%) Candida syp., 6(11.5%) molds, 1(1.9%) mixed infection and 2 samples(3.8%) to be negative.
CONCLUSION
KONCPA test is useful in the diagnosis of onychomycosis because of its higher positive rate in detecting the causative fungi compared with fungus culture or KOH smear. It is also a timesaving and simple procedure Furthermore, in case that KOH smear and fungus culture fail to identify the causative fungi, it is possible to make a presumptive diagnosis by the findings of KONCPA test.