Chemosensory perception, symptoms and autonomic responses during chemical exposure in multiple chemical sensitivity.
OBJECTIVE
Multiple chemical sensitivity (MCS) is a prevalent medically unexplained symptom characterized by symptom reactions to everyday chemical exposure below hygienic thresholds. The aim of this study was to investigate the expressions of hyper-reactivity in MCS during whole-body exposure to low concentrations of the odorant n-butanol.


METHODS
We exposed 18 participants with MCS and 18 non-ill controls to a low concentration of the odorant n-butanol using an exposure chamber. The first 10 min constituted blank exposure, after which the n-butanol concentration increased and reached a plateau at 11.5 mg/m(3).


RESULTS
MCS participants, compared with controls, reported greater perceived odor intensities, more unpleasantness to the exposure and increasing symptoms over time. MCS participants also expressed higher pulse rate and lower pulse rate variability than controls did. No group differences were found for breathing rate or tonic electrodermal activity responses.


CONCLUSIONS
We conclude that MCS sufferers differ from healthy controls in terms of autonomic responses, symptoms and chemosensory perception during chemical exposure.
Department of Occupational and Public Health Sciences, University of Gävle, Johan Bures Väg 13, 907 36, Umeå, Sweden. linus.andersson@psy.umu.se.
Linus
http://orcid.org/0000-0003-4088-0025
L
Andersson
Department of Psychology, Umeå University, 901 87, Umeå, Sweden. anna-sara.claeson@psy.umu.se.
Anna-Sara
AS
Claeson
Danish Research Centre for Chemical Sensitivities, Copenhagen University Hospital Gentofte, Ledreborg Allé 40, 2, 2820, Gentofte, Denmark. Thomas.Meinertz.Dantoft@regionh.dk.|Department of Systems Biology, Center for Biological Sequence Analysis, Technical University of Denmark, Kemitorvet, Building 208, 2800, Lyngby, Denmark. Thomas.Meinertz.Dantoft@regionh.dk.
Thomas Meinertz
TM
Dantoft
Danish Research Centre for Chemical Sensitivities, Copenhagen University Hospital Gentofte, Ledreborg Allé 40, 2, 2820, Gentofte, Denmark. sine.skovbjerg.jakobsen@regionh.dk.
Sine
S
Skovbjerg
Department of Psychology, Umeå University, 901 87, Umeå, Sweden. nina.lind@psy.umu.se.
Nina
N
Lind
Department of Psychology, Umeå University, 901 87, Umeå, Sweden. steven.nordin@psy.umu.se.
Steven
S
Nordin
D020001:1-Butanol / Q000494:pharmacology*; D000328:Adult; D001337:Autonomic Agents / Q000494:pharmacology*; D001341:Autonomic Nervous System / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D018777:Multiple Chemical Sensitivity / Q000503:physiopathology*; D009812:Odorants; D055696:Olfactory Perception / Q000187:drug effects*; D012684:Sensory Thresholds / Q000187:drug effects
D001337:Autonomic Agents; D020001:1-Butanol
Autonomic nervous system; Chemical intolerance; Environmental intolerance; Multiple chemical sensitivity; Olfaction