INCREASED CAPSAICIN-INDUCED SECONDARY HYPERALGESIA AS A MARKER OF ABNORMAL SENSORY ACTIVITY IN PATIENTS WITH FIBROMYALGIA

In this study, capsaicin-induced secondary hyperalgesia was assessed a s a marker of abnormal nociceptive processing in patients with fibromy algia (FM). The area of mechanical secondary hyperalgesia induced by a standard solution of capsaicin placed on the volar forearm was measur ed in ten patients with FM and the results compared to those obtained in ten patients with rheumatoid arthritis (RA) and ten normal subjects . The area of secondary hyperalgesia was found to be substantially inc reased in both the FM and RA groups compared with controls. In the FM group the area of hyperalgesia correlated with the overall pain score and with the joint tenderness score. The results suggest that in FM th ere is enhanced sensitivity of nociceptive neurones at a spinal level, thereby supporting the concept of a generalised disturbance of pain m odulation in this disorder. (C) 1998 Published by Elsevier Science Ire land Ltd. All rights reserved.