What Causes A Light Discoloured Line On The Nose Bridge?

HELLO, MY SON, WHO IS 14, HAS A LIGHT DISCOLORED LINE ON THE BRIDGE OF HIS NOSE. HE PLAYS SPORTS AND IS UNSURE AS TO WHETHER DURING A GAME HE MAY HAVE GOTTEN HIT ON THE NOSE. HE WAS RUBBING CREAM AROUND THE BRIDGE OF NOSE FOR ACNE AS WELL. PLEASE ADVISE THANKS!