My 15 month old will not stop itching the top of her bottom. This has gone on for maybe 2 weeks?

I have tried: hydrocortisone cream, Benadryl cream, butt paste, baking soda bath, oatmeal lotion....

I'm out of ideas.

Pretty sure it's not worms because it is just the top of her diaper area.

Could be the diapers, but we haven't changed brands or anything since she has been born.

I don't know what else to do. surely I don't have to take her to the doctor because she won't stop itching?

No rash that I can see, but her poor fingernails have done some damage. I trim them at least once every two to three days.

Where are my Glow mommy doctors at? Help. It's driving us both crazy.