probably a chicken pox. dont take a bath coz it will spread faster. its contageous to people that still hasn't got it before. becareful coz people will hate you if they know that your the one to spread it.
sounds like an allergy to something. go to the doctors and he will look at it for you.......not chicken pox - they are little blisters. not measles either - you would be really really ill.
Do you feel ok in yourself?? If so, this sounds like a reaction to something. Like the person before said, have you changed your washing powder? I had a reaction like yours myself that was caused by changing washing powder a few years ago. Have you used a new body cream? Anything different that you have put on your skin? It could even be something you ate! If you can't think of anything you've changed and if your symptoms persist than just make an appointment with your Doctor, he'll get to the bottom of it!
I hope this helps!