What you have is probably Scalene Myofascial Pain
Syndrome. When scalene muscle is the cause of pain
, the pain
is referred to chest, inner lining of scapula (shoulder bone), shoulder, posterior and lateral sides of the arm right up to the thumb and index finger.
It is also possible due to peripheral artery disease. Peripheral neuropathies as in diabetes, chemical burns due to any deo or lotions you use, peripheral nerve compression are the other possibilities.