I have red spots blister looking all over stomach, chest, arms and back that have just appeared. no itch. any ideas what it could be?

Body rash: The cause of a rash can sometimes be hard to determine - so usually a good description of the rash, any associated symptoms, environmental exposures, medication usage, 'sick' contacts etc help to make the diagnosis. In your case I'm suspicious for Pityriasis rosea since your not itchy, your trunk is largely involved, your age and seeming lack of other symptoms. Probably a good idea to show a doc.