I Have A Small White In Color Spot Which Felt

I have a small white in color spot which felt like a pimple on my inner buttock cheek at first. I got a rash in the area and on the opposite buttock cheek after using Neosporin ointment so felt I had an allergic reaction to the ointment. I have been using hydrocortisone instead for the rash but the white spot still remains. I am thinking of going to my dermatologist to diagnose.