I'm having itching located under the scrotum. i treated it with topical antifungal cream. it seems to be gone after 10 days but it keeps returning.

Which cream?: You can use many of them forever if need. Suggest Clotrimazole (lotramin) or Miconazole (monistat). The generics are cheaper.

Diagnosis?: Does your antifungal cream contain steroid? If so, it is necessary to make sure if your rash is indeed from funfal infestation or something else such as lichen atrophicus. So, see a knowledgeable expert if the condition persistently recurs.