Species identification of dermatophytes in XXXX -embedded biopsies with a new PCR-assay targeting the ITS 2 region and comparison with histopathological features.

@entity1 @entity4013 @entity14235 @entity982 @entity272 @entity14476 @entity12735 @entity12734 @entity15528
BACKGROUND: @entity4013 is a very common @entity272 with a broad clinical spectrum. Biopsies are often used to confirm the diagnosis, especially when the clinical presentation is unusual. Not uncommonly organisms are hard to find even with Periodic acid-Schiff stains. Polymerase chain reaction (PCR) for dermatophytes can be used in such cases. OBJECTIVES: To test a new PCR-assay allowing species identification of dermatophytes on @entity982 -embedded biopsies; to reassess histopathological criteria for diagnosis of @entity4013 . METHODS: 121 biopsies of 92 @entity1 with clinical suspicion of @entity4013 were included. In 42 samples the clinical diagnosis had been confirmed histopathologically, in 79 no fungal elements had been identified. Polymerase chain reactions (PCR) targeting the ITS 2 region of dermatophytes were performed on the biopsies with subsequent sequencing. Sections were reassessed for the presence/absence of hyphae/spores, pattern and composition of infiltrate, epidermal/follicular changes. @entity1 charts were reviewed for clinical data. RESULTS: The new ITS2 PCR assay detected 94.3% of the dermatophyte infections (compared with 79.2% identified by microscopy). @entity12734 was the dominant species (88.7%), other species identified were @entity12735 (1.9%), @entity14476 (3.8%), @entity15528 (1.9%), T.interdigitale (3.8%). @entity14235 with T.interdigitale and manifestations with prominent spongiosis were not diagnosed histologically. Intracorneal neutrophils which have been emphasized as a histopathological clue to @entity4013 were present in only 46% of PCR-positive samples. CONCLUSIONS: Molecular species identification of dermatophytes via ITS2 PCR can easily be implemented in a routine dermatopathology setting. It is fast, highly specific, and improves the sensitivity of histopathological diagnosis of @entity4013 . This article is protected by copyright. All rights reserved.
