Hi there. This could be CRPS or regional pain syndrome. There is usually no cure for it. Pain can be attempted to be relieved with psychotherapy, physical therapy and drugs like topical analgesics, narcotics, corticosteroids, antidepressants and anti seizure drugs. Other modalities are sympathetic nerve blocks, surgical sympathetectomy, intrathecal drug pumps and spinal cord stimulation. Discuss this possible diagnosis and management modalities with your neurologist. Hope this helps. Take care.
It could be the nerves regaining their feeling if there was nerve damage in the hand. It takes yeas for nerves to heal and can be painful when they do. Also if there is something wrong with the hand it could be pinching a nerve off causing the same kind of pain. Weird I know. He should ask his doctor to do a nerve conduction test so that they know what type of treatment to do. Medications like Gabitril are helpful in either case. Hope this helps. Best wishes.
Sissie