Is ignoring tantrums the only solution?

When my 4 year old gets extremely upset it turns into him screaming as loud as possible for a long time, 20 minutes plus is not uncommon. The only way we have found to get him out of it is to wait until the screams turn to sad crying and then we can give him some comfort (hugs and cuddles) and it's like it never happened. Trying to talk or touch him during the fit is met with just louder screams and turning away.I know about the concept of teaching the child to deal with anger in constructive way, but I'm at a loss on how to do it. And with the mental state he gets into, I'm not sure it would work. Anyone any suggestions on good books for teaching this skill? Anyone have suggestions on what to do when we are already in the extreme tantrum?Example from this morning: both kids wake up and go downstairs to start their morning routine. 4YO comes into my room (I was asleep) and asks if I know where something is. No I don't but I'm happy to help him look for it, give me a minute and I'll come down. Ok daddy I love you he says. Couple minutes later something happened, not sure what the trigger was that got him a little sideways, and I start coming down the hallway and he starts screaming "I don't want daddy, go back to bed". I tell him I'll just go downstairs to see his brother. 20 minutes of screaming as loud as he can and stomping that he doesn't want Daddy. Mom walks by him and says "I'm going to make my breakfast shake, do you want a little". Tantrum ends and he comes and sits with me on the couch immediately and snuggles happy as can be. I'm at a loss.​ via /r/Parenting http://bit.ly/2Uc504Y