No tissue damage and no somatosensory lesion, but increased sensitivity to pain? Use the term nociplastic pain! New pain term from IASP: https://www.iasp-pain.org/Taxonomy

Scandinavian Journal of Pain is accepted for Medline!

An important paper on how to define chronic pain in large surveys were recently published by Steingrimsdottir et al. : 

https://www.ncbi.nlm.nih.gov/pubmed/28767506