Whether it’s chickenpox, ringworm, scarlet fever or whooping cough, there seems to be an endless list of childhood illnesses that children can pick up. And every common childhood illness produces a host of questions. How serious is it? Should I be worried? How long does it last? What if they don’t get it? Well, don’t worry, because we’ve put together the most important facts for the most common childhood illnesses for you in our handy guide.