TY - JOUR

T1 - Multiple chemical sensitivity

T2 - on the scent of central sensitization

AU - Tran, Marie Thi Dao

AU - Arendt-Nielsen, Lars

AU - Kupers, Ron

AU - Elberling, Jesper

N1 - Copyright © 2012 Elsevier GmbH. All rights reserved.

PY - 2013/3

Y1 - 2013/3

N2 - BACKGROUND: Multiple Chemical Sensitivity (MCS) is a chronic condition characterized by recurrent, non-specific symptoms in response to chemically unrelated exposures in non-toxic concentrations. Although the pathophysiology of MCS remains unknown, central sensitization may be an important factor contributing to the clinical manifestations.PURPOSE: To use quantitative sensory testing (QST) to study central hyperexcitability and multiple aspects of central sensory processing in MCS patients without comorbid overlapping disorders and to compare the results with those among matched controls.METHODS: 15 MCS patients and 15 healthy matched controls underwent QST to assess the following aspects of pain: capsaicin-induced secondary punctate hyperalgesia, stimulus response function (SRF) to punctate mechanical stimuli before and after capsaicin injection, temporal summation to punctate stimuli post capsaicin injection, pressure pain thresholds, heat pain thresholds, tonic heat stimulation and conditioning pain modulation (CPM: formerly known as diffuse noxious inhibitory control or DNIC).RESULTS: The mean area of capsaicin-induced secondary punctate hyperalgesia was significantly larger in MCS patients than in controls at 5, 30 and 60 min post capsaicin injection (p=0.01). In addition MCS patients reported higher ratings in response to punctate mechanical stimuli assessed by SRF compared with controls (p<0.001). The CPM test induced significantly higher pain ratings in patients than in controls (p=0.002). We found no group differences in pressure pain and heat pain thresholds, temporal summation to punctate stimuli post capsaicin injection, capsaicin and tonic heat pain ratings or CPM effect.CONCLUSION: Increased capsaicin-induced secondary punctate hyperalgesia was demonstrated in MCS patients without comorbid, overlapping disorders, suggesting facilitated central sensitization in MCS.

AB - BACKGROUND: Multiple Chemical Sensitivity (MCS) is a chronic condition characterized by recurrent, non-specific symptoms in response to chemically unrelated exposures in non-toxic concentrations. Although the pathophysiology of MCS remains unknown, central sensitization may be an important factor contributing to the clinical manifestations.PURPOSE: To use quantitative sensory testing (QST) to study central hyperexcitability and multiple aspects of central sensory processing in MCS patients without comorbid overlapping disorders and to compare the results with those among matched controls.METHODS: 15 MCS patients and 15 healthy matched controls underwent QST to assess the following aspects of pain: capsaicin-induced secondary punctate hyperalgesia, stimulus response function (SRF) to punctate mechanical stimuli before and after capsaicin injection, temporal summation to punctate stimuli post capsaicin injection, pressure pain thresholds, heat pain thresholds, tonic heat stimulation and conditioning pain modulation (CPM: formerly known as diffuse noxious inhibitory control or DNIC).RESULTS: The mean area of capsaicin-induced secondary punctate hyperalgesia was significantly larger in MCS patients than in controls at 5, 30 and 60 min post capsaicin injection (p=0.01). In addition MCS patients reported higher ratings in response to punctate mechanical stimuli assessed by SRF compared with controls (p<0.001). The CPM test induced significantly higher pain ratings in patients than in controls (p=0.002). We found no group differences in pressure pain and heat pain thresholds, temporal summation to punctate stimuli post capsaicin injection, capsaicin and tonic heat pain ratings or CPM effect.CONCLUSION: Increased capsaicin-induced secondary punctate hyperalgesia was demonstrated in MCS patients without comorbid, overlapping disorders, suggesting facilitated central sensitization in MCS.

KW - Adult

KW - Capsaicin

KW - Central Nervous System Sensitization

KW - Cold Temperature

KW - Female

KW - Hot Temperature

KW - Humans

KW - Hyperalgesia

KW - Male

KW - Middle Aged

KW - Multiple Chemical Sensitivity

KW - Pain Measurement

KW - Questionnaires

U2 - 10.1016/j.ijheh.2012.02.010

DO - 10.1016/j.ijheh.2012.02.010

M3 - Journal article

C2 - 22487274

VL - 216

SP - 202

EP - 210

JO - International Journal of Hygiene and Environmental Health

JF - International Journal of Hygiene and Environmental Health

SN - 1438-4639

IS - 2

ER -