Identification of Trichophyton Rubrum by Nested PCR Analysis from Paraffin Embedded Specimen in Trichophytia Profunda Acuta of the Glabrous Skin

A 67-year-old Japanese man with trichophytia profunda acuta of the glabrous skin (TPAGS) presented with erythematous plaques and nodules on his forearm. Traditional diagnostic methods, including KOH preparation and culture, failed to detect fungal elements. However, deep-cut sections stained with PAS revealed fungal presence. Using nested PCR with Trichophyton-specific primers on DNA from paraffin-embedded skin sections, Trichophyton rubrum was identified as the causative agent. This study suggested that nested PCR could be a reliable alternative for identifying fungal infections in cases where conventional methods are unsuccessful.