Athlete's foot fungus. Colored Scanning Electron Micrograph (SEM) of the fungus Trichophyton interdigitale, seen growing on human skin. This fungus causes athlete's foot (tinea pedis) in humans. A network of thin, branching filaments (hyphae) of the fungus has spread among the large, flaky skin scales. T. interdigitale is one of several species of fungi that cause tinea: skin and hair infections like ringworm, jock itch and athlete's foot. Athlete's foot usually affects the skin between the toes, which becomes itchy, sore and cracked. The condition is associated with wearing shoes and sweating. Antifungal creams are used. Magnification: x1,300 at 6x4.5cm size.