title: Desensitization of thermal hyperemia in the skin is reproducible.
abstract: OBJECTIVE
  Local heating increases skin blood flow SkBF (thermal hyperemia). In a previous study, we reported that a first local thermal stimulus could attenuate the hyperemic response to a second one applied later on the same skin spot, a phenomenon that we termed desensitization. However, other studies found no evidence for desensitization in similar conditions. The aim of the present work was to test whether it was related to differences in instrumentation.
  
  
  METHODS
  Twenty-eight healthy young males were studied. Two pairs of heating chambers, one custom-made (our study) and one commercial (other groups), were affixed to forearm skin. SkBF was measured with single-point laser-Doppler flowmetry (LDF) (780nm) in one pair, and laser-Doppler imaging (LDI) (633nm) in the other. A temperature step from 34 to 41°C, was applied for 30minutes and repeated after two hours.
  
  
  RESULTS
  During the second thermal challenge, the plateau SkBF was lower than during the first thermal and was observed with each of the four combinations of SkBF measurement techniques and heating equipment (p<0.05 for all conditions, range -9% to -16% of the initial value).
  
  
  CONCLUSIONS
  Desensitization of thermal hyperemia is not specific to peculiar operating conditions.
authors.affiliation: Division de Physiopathologie Clinique, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Switzerland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Frantz
authors.forename: Rolf Peter
authors.initials: RP
authors.lastname: Engelberger
authors.forename: Lucas
authors.initials: L
authors.lastname: Liaudet
authors.forename: Lucia
authors.initials: L
authors.lastname: Mazzolai
authors.forename: Bernard
authors.initials: B
authors.lastname: Waeber
authors.forename: François
authors.initials: F
authors.lastname: Feihl
mesh_terms: D000293:Adolescent; D000328:Adult; D006358:Hot Temperature; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012867:Skin / Q000098:blood supply*; D013997:Time Factors