[2][3] Diagnostic approaches of the fungal infection include physical examination, culture testing, and molecular detection.

[2][9] The fungus was first isolated in 1870 from a tinea cruris patient in Germany by Carl Otto Harz, who named it Acrothecium floccosum.

[4] In 1930, based on the principle of priority, Langeron and Milochevitch renamed the fungus Epidermophyton floccosum to recognize Harz's contribution in identifying the species first, as well as his extensive morphological descriptions.

[11] Another fungus, originally named Epidermophyton stockdaleae, is a dark-brown, soil-inhabiting species that is morphologically and molecularly distinct to E. floccosum for its longer conidia and 7% NaCl tolerance.

[4] Due to the presence of microconidia, E. stockdaleae is now considered a synonym of Trichophyton ajelloi, hence E. floccosum is currently the only species in the genus Epidermophyton.

[6][9] Arthroconidia are also abundant in the culture, emerging as swollen cells alongside macroconidia formation; these thick-walled spores are resistant to heat and drying conditions.

[2] The infection typically stays within the nonliving conidified layer of host epidermis, since the fungus cannot pierce through living tissues of individuals with normal immunity.

However, it has been found to cause invasive infections in immunocompromised patients, demonstrating severe onychomycosis, skin lesions, and subcutaneous nodules.

[2] Arthroconidia formation allows E. floccosum to survive for years in showers, baths, swimming pools, towels, blankets, sheets, shoes and other clothing.

Samples obtained from patient nail, hair, and skin scale can undergo PCR-RFLP, which distinguishes between 12 dermatophyte species based on their individual restriction enzyme profiles, including one for E. floccosum.

A real time PCR protocol is also available for the specific detection of E. floccosum, allowing identification as fast as 4 hours after sample lysis.