Symptoms that my son has are itching, bloating, blue lines on chest, some chest pain and achy joints. Do u know what this could be?

A lot of things. Each symptom has a long list of possibilities. If this is relatively new process then most likely viral. If this is a longer term problem sounds like an inflamatory process. Either way would seek medical care relatively soon if your son is an infant or unable to tolerater oral liquids solids goto emergancy department.