My mother, age 82, has been having muscle spasms in her upper back, shoulder area. No problems there before. Been going on for about 1 week, and we were thinking it is a pulled muscle. (She woke up with it one morning...thought is was a crick in her neck.). Now she is running 100 degree temp, and her upper arm has 2 water blisters on it about the size 1/2 inch x 1/4 inch, and her arm is warm to the touch. The area where the blisters are is hard and lumpy.