Have you tried numerous ways to get your child to stop screaming? I suggest you offer your child an appropriate way to release the need to scream. Have them help you make a "SCREAM Box." It's easy to make and can be used whenever your child feels the "need to scream".
Fill a cereal box with crumpled newspaper or grocery bags. Stuff more newspaper halfway up a paper towel tube. The newspaper muffles the screaming. Cut a hole in one of the top flaps big enough for the paper towel tube to fit through. Tape the box closed with the tube half way out of the box. Cover the box with paper and decorate it with words or pictures.
Put the tube up to your mouth and "LET IT OUT!" Children and even parents can release pent up anger by screaming into this box. Make one today because sometimes you just have to scream.