title: Skin colour changes during experimentally-induced sickness.
abstract: Skin colour may be an important cue to detect sickness in humans but how skin colour changes with acute sickness is currently unknown. To determine possible colour changes, 22 healthy Caucasian participants were injected twice, once with lipopolysaccharide (LPS, at a dose of 2ng/kg body weight) and once with placebo (saline), in a randomised cross-over design study. Skin colour across 3 arm and 3 face locations was recorded spectrophotometrically over a period of 8h in terms of lightness (L∗), redness (a∗) and yellowness (b∗) in a manner that is consistent with human colour perception. In addition, carotenoid status was assessed as we predicted that a decrease it skin yellowness would reflect a drop in skin carotenoids. We found an early change in skin colouration 1-3h post LPS injection with facial skin becoming lighter and less red whilst arm skin become darker but also less red and less yellow. The LPS injection also caused a drop in plasma carotenoids from 3h onwards. However, the timing of the carotenoid changes was not consistent with the skin colour changes suggesting that other mechanisms, such as a reduction of blood perfusion, oxygenation or composition. This is the first experimental study characterising skin colour associated with acute illness, and shows that changes occur early in the development of the sickness response. Colour changes may serve as a cue to health, prompting actions from others in terms of care-giving or disease avoidance. Specific mechanisms underlying these colour changes require further investigation.
authors.affiliation: School of Psychology and Neuroscience, University of St Andrews, Scotland, United Kingdom. Electronic address: ajw29@st-andrews.ac.uk.
authors.forename: Audrey J
authors.initials: AJ
authors.lastname: Henderson
authors.affiliation: Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm University and Karolinska Institutet, Stockholm, Sweden; Institute of Medical Psychology and Behavioral Immunobiology, Universitätsklinikum, Essen, Germany.
authors.forename: Julie
authors.initials: J
authors.lastname: Lasselin
authors.affiliation: Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm University and Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Lekander
authors.affiliation: Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mats J
authors.initials: MJ
authors.lastname: Olsson
authors.affiliation: School of Medicine, University of St Andrews, Scotland, United Kingdom.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Powis
authors.affiliation: Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm University and Karolinska Institutet, Stockholm, Sweden.
authors.forename: John
authors.initials: J
authors.lastname: Axelsson
authors.affiliation: School of Psychology and Neuroscience, University of St Andrews, Scotland, United Kingdom.
authors.forename: David I
authors.initials: DI
authors.lastname: Perrett
mesh_terms: D000328:Adult; D002338:Carotenoids / Q000494:pharmacology*; D018592:Cross-Over Studies; D005145:Face / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D012867:Skin / Q000473:pathology*; D012880:Skin Pigmentation / Q000187:drug effects* / Q000502:physiology; D044465:White People; D055815:Young Adult
chemical_list: D002338:Carotenoids
keywords: Blood; Carotenoids; Inflammation; Lipopolysaccharide; Sickness response; Skin colour; Spectrophotometry