The surname Nguyen is believed to have originated in the Chinese surname Ruan (in the Mandarin language) or Yuen (Cantonese), owing to Chinaâs long domination over Vietnam.
Tinea nigra is a fungal infection that is mainly seen on the palms of the hands or soles of the feet causing a dark brown to black discoloration of the affected skin. The word tinea means a fungal infection and nigra means black.
Toenail fungus, or onychomycosis, is an infection underneath the surface of the nail caused by fungi. When the tiny organisms take hold, the nail often becomes darker in color and smells foul.