Fifths Disease More Condition_symptoms When An Article Refers To The "trunk" On Your Body, What Part Of Your Body Is That? Fifths Disease?

When an article refers to the "trunk" on your body, what part of your body is that? Fifths Disease? - fifths disease more condition_symptoms

I have read an article on the fifth disease, I think, my child, not bright red cheeks, slight fever, colds, etc., say, skin rash on the trunk. How old are you master is someone you know has fifth disease?