Apart from HPV, absence of symptoms in men is pretty good reassurance, but not perfect. Symptoms are relative; persons who are very body-aware and are looking for symptoms or signs of infection usually will see something if they get chlamydia, gonorrhea, or syphilis, and often herpes (but usually not HPV).
In any case, I doubt your partner has an STD or anything else she caught sexually from you. As I said, lack of symptoms indicates you probably don't have anything; and her symptoms don't sound like any of the common STDs. (In theory one might be concerned about herpes and syphilis, but it's highly atypical for herpes, and syphilis symptoms would have cleared up with penicillin.)
As to what she has, I can't speculate; and certainly would not recommend any OTC therapy without knowing what is being treated. She should see a health care provider if the problem persists.
Good luck-- HHH, MD
Thank You - John
HHH, MD