title: Progression of ulcerative dermatitis lesions in C57BL/6Crl mice and the development of a scoring system for dermatitis lesions.
abstract: Ulcerative dermatitis (UD) is a common, spontaneous condition in mice with a C57BL/6 background. Although initial lesions may be mild, UD is a progressive disease that often results in ulcerations or debilitating fibrotic contractures. In addition, lesions typically are unresponsive  to treatment. Euthanasia is often warranted in severe cases, thereby affecting study outcomes through the loss of research subjects. Because the clinical assessment of UD can be subjective, a quantitative scoring method and documentation of the likely time-frame of progression may be helpful  in predicting when animals that develop dermatitis should be removed from a study. Such a system may also be helpful in quantitatively assessing success of various treatment strategies and be valuable to clinical laboratory animal veterinarians. In this 1.5-y, prospective cohort study, we  followed 200 mice to monitor the development and course of UD. Mice were examined every 2 wk. A clinical sign (alopecia, pruritus, or peripheral lymphadenopathy) was not identified that predicted development of UD lesions in the subsequent 2-wk period. Once UD developed, pruritus, the character  of the lesion (single or multiple crust, coalescing crust, erosion, or ulceration), and the size of the lesion were the only parameters that changed (increased) over the course of the disease. Pruritus was a factor in the rapid progression of UD lesions. We used these findings to develop a  quantitative scoring system for the severity of UD. This enhanced understanding of the progression of UD and the quantitative scoring system will enhance the monitoring of UD.
authors: Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, Michigan, USA. Anna.L.Hampton@gmail.com
authors: Anna L
authors: AL
authors: Hampton
authors: Gerald A
authors: GA
authors: Hish
authors: Muhammad N
authors: MN
authors: Aslam
authors: Edward D
authors: ED
authors: Rothman
authors: Ingrid L
authors: IL
authors: Bergin
authors: Kathleen A
authors: KA
authors: Patterson
authors: Madhav
authors: M
authors: Naik
authors: Tejaswi
authors: T
authors: Paruchuri
authors: James
authors: J
authors: Varani
authors: Howard G
authors: HG
authors: Rush
mesh_terms: D000818:Animals; D000830:Animals, Laboratory; D015331:Cohort Studies; D003872:Dermatitis / Q000175:diagnosis / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D018450:Disease Progression; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011446:Prospective Studies; D011537:Pruritus / Q000209:etiology / Q000662:veterinary; D012376:Rodent Diseases / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D012883:Skin Ulcer / Q000175:diagnosis / Q000209:etiology / Q000473:pathology / Q000662:veterinary*