title: Are the infrared thermography findings skin temperature-dependent? a study on neck pain patients.
abstract: BACKGROUND
  Skin temperature (Tsk) disorders have been proposed as sign of impaired innervation in several conditions, but the influence of different factors on the infrared thermography (IRT) findings remains unclear.
  
  
  METHODS
  The relations between the Tsk and δT (side-to-side temperature difference) values, and influence of age, gender, anthropometric characteristics and pain intensity on those values were analysed in non-specific neck pain (NP) patients (n = 91) using mixed model analysis. IRT findings were also compared in subgroups of NP patients: with cold (CHNPP, n = 21) or warm hands (WHNPP, n = 56) and healthy controls, with cold (CHC, n = 11) or warm hands (WHC, n = 19). Also, the stability of δT values in CHNPP was examined.
  
  
  RESULTS
  Only the area of measurement and the actual Tsk influenced the δT values. CHNPP demonstrated higher δT values in distal parts, compared with WHNPP and controls, but those values vanished when their hands turned warm. δT values in CHNPP were related to the pain intensity. The findings of WHNPP and WHC did not differ.
  
  
  CONCLUSIONS
  Our results suggest that the δT values as signs of impaired Tsk regulation are dynamic and better detectable in cold skin. The results underline the need of caution in interpretation of IRT findings.
authors.affiliation: Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland. nina.zaproudina@uef.fi
authors.forename: Nina
authors.initials: N
authors.lastname: Zaproudina
authors.forename: Olavi
authors.initials: O
authors.lastname: Airaksinen
authors.forename: Matti
authors.initials: M
authors.lastname: Närhi
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis / Q000503:physiopathology*; D004185:Disability Evaluation; D005260:Female; D006225:Hand / Q000098:blood supply / Q000294:innervation / Q000502:physiology; D006801:Humans; D007259:Infrared Rays; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000098:blood supply / Q000294:innervation / Q000502:physiology; D019547:Neck Pain / Q000175:diagnosis / Q000503:physiopathology*; D015203:Reproducibility of Results; D012867:Skin / Q000098:blood supply / Q000294:innervation; D012881:Skin Temperature / Q000502:physiology*; D011795:Surveys and Questionnaires; D013564:Sympathetic Nervous System / Q000503:physiopathology; D013817:Thermography / Q000379:methods* / Q000592:standards*