Talk to Pediatrician on Baby Boy, Age 19 Months, White Patches With Body Scratches

Baby boy age is 19 months. Initially scratches were started on legs around hips and in the beginnings these turned into wounds by scratching, but now almost full body is dry rough with scratch specially at night and when ever sleeps, baby keep rubbing his body. Body surface is turned into many small white patches lower portion of the body is extremely effected. It was started a month ago, we took some medicines for the time being but now it has enhanced enough on arms, legs, hips beneath the chin almost full body is effected. Skin is very much rough to touch, i messages him almost daily with mustered oil but in vein. So much worried, please suggest any solution.... Thank you