Definitely look up Fibro jgr. Sore patches on the skin are really common. Sometimes it's as if you've knocked it and should have a bruise and also you can feel as if the skin is burnt and anything touching it such as clothes, bedding etc. causes real pain but there s nothing to see on the outside. Aching muscles are also part of it although not so much joint pain. Quite often the pain is symmetrical. Typical tender points are the wrists, inside of the elbows, top of the shoulders (outside edge sort of) outer edge of hips, inside ankle bones, bony edge of the collar bone by the throat etc.
Taz x