There are A LOT of people who are affected by chronic pain of one sort or another. Maybe broaden your search to look at techniques for coping with chronic pain such as meditation, biofeedback, cognitive behavioral therapy, etc. What sorts of treatments has he had for chronic pain?
I don't know that you'll net that much under sensory and a problem that affects primarily teenagers because typically sensory concerns lessen over time as the nervous system matures. So, for most kids into the teenage years it isn't really a stand alone diagnosis but would be more often seen with something like autism.
Even if the chronic pain management techniques aren't perfect DOING something, anything about pain can be a helpful thing. And getting some help with the emotional aspects of having his teen years be so disrupted would probably be helpful.
