I would assume the STD check included standard tests looking for gonorrhea, chlamydia, herpes and syphillis.
A fungal infection or dermatitis (inflammation) of the skin can lead to these findings. Appropriate treatment would be with an antifungal or steroid cream respectively.
I would consider a referral to a dermatologist for a more comprehensive evaluation.
This option can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
kevinmd_