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.
Brown toenails, scientifically called onychomycosis, signal that there is a fungal infection on the nails. Fungus grows and thrives on toes and feet because they are usually covered in socks and shoes, creating a hot and moist environment. Once the fungus grows, it will discolor your toenails with a dull brown color.