Sáenz RAV, Medina VNA, Vega SDC, Moreno CG, Arenas R

Language: Spanish
References: 10
Page: 151-156
PDF size: 282.73 Kb.

ABSTRACT

Background: dermatophytes are the fungal pathogens responsible for the majority of skin and nail infections. The estimated lifetime risk of developing dermatophytosis is 10 to 20%. The accurate identification of these agents is essential for effective treatment and prevention of spread. In this context, mycological diagnostic methods are crucial in providing guiding information for treatment.
Objective: to determine the diagnostic efficacy of the direct examination with calcofluor white compared to the direct examination with KOH-chlorazol black for the identification of dermatophytes in patients clinically diagnosed with dermatophytosis at Dr. Manuel Gea González General Hospital during 2019.
Methodology: a descriptive, comparative, prospective, observational, and cross-sectional study was conducted focusing on dermatophytosis. The analysis centered on negative results from direct examinations using koh-chlorazol black on samples from patients at the Dr. Manuel Gea González General Hospital. Subsequently, a new set of direct examinations was performed using calcofluor white and fluorescence.
Results: a total of 504 dermatophytosis cases were examined using KOH-chlorazol black. 50.7% tested positive, 49% negative. Negative samples (n = 248) were re-evaluated with calcofluor white, detecting an additional 16.5%. Onychomycosis was the most common diagnosis in negatives (72%). Calcofluor white positively identified 13% of previously undetected cases, with 100% sensitivity and 83.5% specificity. The positive predictive value was 86%, and the negative predictive value was 100%.
Conclusions: the comparative study between calcofluor white and chlorazol-black KOH revealed significant results in the diagnosis of dermatophytosis. Calcofluor white showed great effectiveness, identifying cases that could go unnoticed with the conventional method.

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