Trichophyton rubrum may be asymptomatic when carried on a person’s skin and is a latent state infection, i.e. what patients usually refer to as untreated more obvious foot odor that has healed itself. In fact, foot odor cannot heal itself, it is only in an inactive state and can recur if the patient walks in shoes for a long time. More often than not, Trichophyton rubrum causes symptoms, the infection appears as small bumps and blisters, the area expands and peels children, after a longer period of time, the skin on the palms of the hands or soles of the feet thickens and has cracks, after the infection reaches the nails, there may be symptoms of thickening and yellowing of the nails, the contamination can also turn gray, the texture of the nail plate becomes brittle and easy to fall off by force, or only part of the nail may grow. Outside the human body, only in the laboratory can be found a suitable medium for the growth of Trichophyton rubrum. After inoculation and growth, Trichophyton rubrum behaves as white or light red fluffy colonies. If placed under a microscope, the colony can be observed to be composed of a large number of hyphae and occasionally a variable number of spores, the seeds of Trichophyton rubrum.