I have scabies and put on the permethrine creame can i put on hydrocortisone after and still have same affect?

Hard to say: I can't recall any studies where this has been looked at. I would recommend waiting on the HC until you have washed off the permethrin cream. This would allow the killing of the scabies to occur & then remove the residual and somewhat toxic material. With a fresh/clean surface the HC is more likely to penetrate/cover the areas & begin providing its anti-inflammatory effect.