Morphometric Analyses of the Skin of Dogs with Atopic Dermatitis and Correlations with Cutaneous and Plasma Histamine and Total Serum IgE

Abstract

In order to improve the diagnostic value of histopathologic examination of skin biopsy samples from dogs with atopic dermatitis and, perhaps, to identify any differences from the normal state that may predispose to this skin condition, we compared the anatomic and cellular morphology of skin from three standard sites in 21 normal and 15 atopic dogs. The standard sites were lateral neck, dorsal rump, and craniolateral abdomen. No differences between the two groups were found in the means of area or thickness of the stratum corneum or the remainder of the epidermis at any site. The area of sebaceous glands, but not apocrine sweat glands, was larger in the atopic group (P less than or equal to 0.05 for the lateral neck skin and P less than or equal to 0.1 for the dorsal rump skin). The mean number of non-metachromatic mononuclear cells in combined skin samples (126 microns 2) in atopic dogs (91.0 +/- 28.7) was significantly greater (P less than or equal to 0.01) than for the control normal dogs (65.3 +/- 19.3); the mean number of mast cells in atopic dogs (12.39 +/- 6.44) was similarly greater than in the controls (8.48 +/- 5.14; P less than or equal to 0.1). Eosinophils were significantly increased in atopic dog skin (P less than or equal to 0.01). with the mean for all three sites combined of 0.81 +/- 0.90 compared with a mean of 0.06 +/- 0.15 for normal dogs. Numbers of circulating blood eosinophils were not significantly different in the atopic and normal group.(ABSTRACT TRUNCATED AT 250 WORDS)