Thumb Pain, Beginning With D Unexplained Pain/ache/tenderness In Right Arm.. What Could Be Causing It?

Unexplained pain/ache/tenderness in right arm.. What could be causing it? - thumb pain, beginning with d

It started a week ago, maybe two weeks ago.
Thumb starts badly injured, with the side of my arm. It was a very strong pain, and appeared out of nowhere. Then I had an outbreak of herpes whitlow in my right thumb, so I paid no attention to my pain .. Pages, but it has now changed my arm. Well, my little finger and ring known (with that side of my arm to the elbow) .. Last time my thumb, index finger and the left side of the fingers were soft.
It responds to touch, no swelling or obvious trauma. It seems, however, as well as sensitive to cold.
It is very difficult to explain.
All ideas what might be? I tried to search .. but no luck. I wonder whether it might have something to do with nerve damage?
Well .. Thank you for a response from WHO. : D