Some conditions are peculiar to the genitals, but most genital rashes are simply the many causes of skin rash
anywhere on the body
. The only STD that conceivably could be responsible is syphilis
, but that also seems very unlikely.
If this problem clears up, which I expect it will do, I would just let it go. If it persists, you should seek professional attention, perhaps from a dermatologist. Whatever is going on, you really shouldn't be concerned about HPV, herpes, or any other STD.