DIAGNOSTIC MANAGEMENT OF PATIENTS WITH ONYCHOMYCOSES.

Abstract

Introduction: Onychomycosis is a fungal infection of the nail, causing discoloration and thickening of the affected nail plate, and is the most common nail infection worldwide. Microscopy and fungal culture are the gold standard techniques for onychomycosis diagnosis. At the same time, the culture method is long-term and requires significant costs. In this regard, a promising direction in laboratory diagnostics of onychomycosis is the detection of genetic markers of onychomycosis pathogens using polymerase chain reaction. The goal of current work is optimization of diagnostic care for patients with onychomycosis through the use of PCR, epiluminescent diagnostics and therapeutic agents that improve the structure of nail plates.

Material and methods: The work is based on the results of observations of 343 patients with fungal lesions of the nails of the hands and feet, which were on inpatient and outpatient treatment, as well as data from laboratory and instrumental studies. Mycological examination of patients included microscopic examination of pathological material (pieces of nail fragments) and cultural study. PCR was performed using a reagent kit with primers to determine the presence of DNA specific to Trichophyton rubrum and PCR with panfungal primers. Epiluminescence surface microscopy of affected nail plates was performed.

Results: After calculations using standard methods, it was determined that the sensitivity for PCR is 91.9%, for microscopy - 75.9%, for culture - only 44.3%. The specificity for PCR is 71.4%, for microscopy - 83.3%, for culture - 100.0%. The diagnostic accuracy rate for PCR was 90.3%, for microscopy - 76.3%, and for culture - 47.3%. The higher the sensitivity of the method, the more often pathological changes are detected with their help, and accordingly, the more effective it is. The excess of PCR sensitivity rates compared to microscopy by 16.0% and culture by 47.6% and the high specificity rate (71.4%) indicate the possibility of increasing the detection of patients with onychomycosis through the use of the molecular method of research.

Conclusions: The proposed algorithm for managing patients and a comprehensive method of treating patients with onychomycosis, involving both antifungal agents and drugs, contributes to obtaining a timely diagnosis and prescribing therapy aimed at improving the structure of the nail plates.