Low CK, muscle pain, odd tapioca like bumps on sides of fingers, ulcer on toes

hello,

im a 33 yr old female. ive had problems for the last two months with muscle pain, loss of periphial vision, spasmodic dysphonia (getting better), extreme heartburn, numbness and loss of feeling in right foot occasionally.

i had several blood tests done, the only thing that came up low was my creatine kinase. the first time they did the test, it was 21. they did it again a month later and its at 15. my right foot (specifically the big toe and heel) goes numb sometimes for days. i have noticed these hard, tapioca like bumps on the outside of my fingers recently too. i had two of them that i was able to get a white substance out of that have now created this peeling on my fingers as it goes away. My right hand feels extremely tight, swollen, and has redness over the joints.

Any ideas what could cause the low CK? Also, any ideas on what this could be? Ive been tested for SLE, Dermatomyositis, Myasthenia Gravis. All of those were negative.