Secondary heat hyperalgesia detected by radiant heat stimuli in humans: Evaluation of stimulus intensity and duration

Abstract

Diverging observations on secondary hyperalgesia to heat stimuli have been reported in the literature. No studies have investigated the importance of heat stimulus intensity and duration for the assessment of secondary heat hyperalgesia. The present study was designed to investigate systematically ( 1) if pain sensitivity to radiant heat stimuli ( focused Xenon light) is altered in the area of secondary punctuate hyperalgesia induced by intradermal injection of capsaicin and ( 2) if heat stimulus duration and intensity had an influence on the ability to detect secondary heat hyperalgesia.