Central sensitization and cutaneous hyperalgesia

Injury to the skin results in exaggerated pain both at the site of injury as well as in surrounding undamaged tissues. In this study the general organization of the somatosensory system is briefly reviewed, and then the neural mechanisms that account for hypersensitivity after cutaneous injury are discussed. In brief, exaggerated responsiveness, or sensitization, of primary afferent fibers in the skin account for hyperalgesia at the site of injury, whereas sensitization of spinal projection neurons, in particular spinothalamic and spinomesencephalic neurons, account for hyperalgesia in undamaged tissues surrounding the injury site.