This patient presented with ringworm of the foot (tinea pedis) due to the dermatophytic fungus Trichophyton rubrum. Individuals who practice generally poor hygiene, wear enclosed footwear such as tennis shoes, endure prolonged wetting of the skin, i.e. sweating during exercise, and suffer with minor skin or nail injuries are more prone to suffer from tinea infections.

Skin, Skin and Connective Tissue Diseases, Fungal Diseases, Tinea Pedis

Picture & text from CDC/PHIL. For more information see Athletes Foot Pictures from CDC or Ringworm Pictures from CDC