title: Correlation between pruritus score and grossly visible erythema in dogs.
abstract: The severity of pruritus and the extent and severity of erythema were quantified in 107 dogs presenting with various dermatoses. Pruritus was assessed using a previously validated scale, and erythema was quantified by assessing severity at 72 different body sites. Pruritus scores were either 0, or followed a normal type of distribution, with most dogs having a score in the middle of the range and a few dogs having low or high scores. The median pruritus score was 6.3/10. Erythema scores were heavily skewed towards lower values, with only a few dogs having high scores. The median diffuse erythema score was 6.0/216 and the median score for maculo-papular/pustular erythema was 0/1080. Pruritus and erythema scores were significantly correlated with a Spearman rank correlation coefficient of 0.4062 (P<0.001). However, visual assessment of the data representing the two variables revealed that this was not a consistent biological or clinically relevant correlation. Individual dogs could have a high pruritus score with low erythema score or vice versa. This study raises questions about the use of erythema scoring systems as a primary outcome measure in clinical trials, and also about the role of various inflammatory mediators in the pathogenesis of canine pruritus.
authors.affiliation: Veterinary Specialist Centre, PO Box 307, North Ryde, NSW 1670, Australia. phill@vetspecialist.com.au
authors.forename: Peter
authors.initials: P
authors.lastname: Hill
authors.forename: Jan
authors.initials: J
authors.lastname: Rybníček
authors.forename: Peri
authors.initials: P
authors.lastname: Lau-Gillard
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D004890:Erythema / Q000473:pathology / Q000662:veterinary*; D010147:Pain Measurement / Q000662:veterinary*; D011537:Pruritus / Q000473:pathology / Q000662:veterinary*