Fights Foot Fungus: There are numerous types of foot fungus, ranging from mild to severe and, in some cases, contagious. Foot fungus develops as a result of an unsanitary environment in which the fungus grows and causes infection in the foot and nails. If not treated promptly, these fungal infections spread to the foot, causing the nails to deteriorate. The skin of the foot becomes infected as well, causing severe irritability, itchiness, color change, dryness, and pain.