Allergies, brain injuries, tumors, and diseases can cause a sort of short circuiting of the brain which makes him unable to control his behavior. Mental and/or physical abuse can cause a rage that the child hasn't learned to control. Who was his babysitter before he could learn to talk? Could that person's influence be part of the problem? The normal healthy child wants almost desperately to please those dear to him, so something clearly is wrong. Have his physician order appropriate testing to see that everything is as it should be in his brain (with special attention to any area that looks squeezed or compressed or malformed, and developing tumors) and get behavioral counseling for your son. The whole family needs to learn how to respond to his behaviour to enable him to change his behavior, even if there's something structurally wrong in the brain. It would help immensely if each family member could learn things to say and do that would create the desire within your son to want to please them, be good and kind to them. Could his actions be because he's powerless to help you and you are being abused? Whether it's physical or emotional, his recovery should involve counseling for the entire family. Educate yourself as to the incredible problems that can be caused by food and environmental toxins. Just dumping a medium to large saucepan of cold water over the head of someone in a temper tantrum, then walking away, works wonders! Of course, you've got to clean up the water, but not immediately; just pour and walk away. Don't know how approving the child psychologists would be, but it definitely works! Either ignore the demands to know why you did that, or say with deep concern, "Your face was so red I thought maybe you were going to catch fire, so I just wanted to make sure that wouldn't happen. Are you feeling better, now?" Then it's time for a hug. Best of luck to you in getting help for your son---and smother him with love.
This sounds like a serious family problem I would advise you get some help for your son he sounds very upset by something, Ask your Doctor to check him out and get some counselling help ,,Good luck