Fig. 3. Changes in somatosensory perception to natural stimuli after experimental skin incision (Z-score QST profile). (A ) The QST profile after incision in units of SD to the uninjured control site shows an enhanced warm sensation and heat hyperalgesia at the site of the incision (primary zone). Cold detection threshold, thermal sensory limen, and cold pain threshold remained unaltered after skin incision. (B ) In an area surrounding the injured skin (secondary zone), mechanical hyperalgesia to pinprick (MPT, MPS) was induced by the skin incision, whereas the windup ratio as well as the mechanical and vibration detection threshold remained unaltered after skin incision. Each data point represents the Z-score of the examined QST parameters in units of standard normal distribution. CDT = cold detection threshold; CPT = cold pain threshold; HPT = heat pain threshold; MDT = mechanical detection threshold; MPS = mechanical pain sensitivity; MPT = mechanical pain threshold; QST = quantitative sensory testing; TSL = thermal sensory limen; VDT = vibration detection threshold; WDT = warm detection threshold; WUR = windup ratio. Asterisk =P < 0.05, double asterisk =P < 0.01 (paired Student t test). Mean ± SEM values across 20 subjects. All data were averaged over three measurements (1, 3, and 9 h after incision).