Small red spots on chest.?

From your description, i think you're talking about a disease called "pityriasis rosea". Are they slightly scaley and raised above the surface of the skin? They are caused by an over production of sebum (oil) and it is the skins way of treating it. If you go to the doctors or a dermatologist they will do a sc of one of the lesions and check it under a microscope to be sure, then you will be given a cream to apply to the affected area.