I do have an elaborate and extensive relation between pain (somatization) and DPDR. However, in me it is always related to processing the trauma and living with anxiety, and I still cannot say how it exactly works; but I wouldn't say that the pain brings the DPDR, but rather that it accompanies it at certain phases. At other times, DPDR would actually cut me off from almost all bodily sensations.
However, sometimes, when I was excruciatingly depersonalized, to the extent of losing myself almost completely (best way to describe it as being almost totally erased as a person), I would become terribly sick, with pains bolting throughout my body, fever rising and even some other symptoms that mimic flu appearing, and this physical pain and general malaise would actually anchor me back into the body. This happened several times in my life, when I was particularly frightened for myself, as I was detached beyond recognition from who or what I am at that point, and I think this fear had thrown loads of pain my way in order to bring back some sens of self.
Interesting topic, anyway...