Application of polymerase chain reaction in the diagnosis of tinea incognito with fungal blisters or pustules

Abstract

Abstract: Objective To analyze the clinical value of polymerase chain reaction (PCR) in fungal blisters or pustules to diagnose tinea incognito. Methods From July 2020 to October 2021, thirty-four patients presenting tinea incognito with blisters or pustules in the outpatient department of our hospital (Shanghai Skin Disease Hospital) were included. PCR was performed in blister or pustule fluid specimens from 34 patients and compared by fluorescent staining microscopy and fungal culture. Results Blister or pustule fluid specimens were collected from a total of 34 patients. For fluorescent staining microscopy, fungal culture and PCR, the sensitivities were 100%, 77.8% and 100%, the specificities were 87.5%, 100% and 75%, the positive predictive values were 85.7%, 100% and 75%, the negative predictive values were 100%, 80% and 100%, the accuracy were 94.1%,88.2% and 88.2%, respectively. DNA extraction from blister or pustule fluid, PCR amplification and sequencing comparisons were completed within 12 hours, which identified six species and 22 cases of fungi (one case was identified to genus). Conclusion In the diagnosis of tinea incognito with fungal blisters or pustules, PCR has good sensitivity and accuracy. PCR can determine the fungal species compared with fluorescent staining microscopy and shorten the time compared to fungal culture, which can provide reference value for rapid clinical diagnosis and timely treatment of tinea incognito.

Key words: PCR, tinea incognito, blister fluid, fungus identification

CLC Number:

R756

XIA Hui, YANG Hong, ZHANG Pengfei, MO Xiaohui, TAN Fei. Application of polymerase chain reaction in the diagnosis of tinea incognito with fungal blisters or pustules[J]. Chinese Journal of Mycology, 2022, 17(2): 115-119,128.

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