Dermatophytes are filamentous fungi that infect tissues in which abundant keratin occurs (skin, hair, nails).
The most known Dermatomykosen come from the Trychophyton species and are called Tinea. A tinea pedis is therefore a fungal infection of the foot (i.e. a foot fungus) with Trychophyton species.
https://de.wikipedia.org/wiki/Dermatophyt (Wikipedia CC-by-sa-3.0)