What Causes The Accumulation Of Yellow Substance On The Scrotum?

good morning, i seem to have a yellow-ish wax build up on my scrotum/taint area. not able to 'wash' it off. not real bad, but there nonetheless. i do shower in a gym, i have had to treat athletes foot a few times a year.

in my searches before i found this site, i have found "trichomycosis axillaris" or Piedra??

no real odor associated with it, but it seems to be not easily remedied. any suggestions? have you heard of this before?