Hello and welcome to HCM,
If any rash is found on the external genitalia, sexually transmitted diseases (STDs) should be ruled out in the first place especially in sexually active people.
STDs are characterized by rash, discharge,
lymph node enlargement, itching,
dysuria etc.
All these or few symptoms may be present.
If none of these symptoms are present, a primary skin problem is suspected.
Psoriasis is one of conditions which causes
erythematous rash, covered by silvery scales, not painful, not itchy.
However, this is one of the conditions, many other lesions may also present in the similar manner.
You need to
consult a dermatologist for clinical examination. relevant investigations and thus management.
Thanks and take care
Dr Shailja P Wahal