title: Determination of threshold concentrations of allergens and evaluation of two different histamine concentrations in canine intradermal testing.
abstract: The purpose of this study was to determine the optimal histamine concentration and allergen threshold concentrations for canine intradermal testing. Thirty healthy dogs were tested using two different concentrations of histamine and four different concentrations of each allergen. The optimal histamine concentration was determined to be 1:10 000 w/v. The threshold concentration was at least 1750 PNU/mL for all tested grasses, weeds, trees, moulds and insects, except for fleas which was as least 1:500 w/v. For Dermatophagoides pteronyssinus, the optimal threshold concentration was 250 PNU/mL, whereas for Dermatophagoides farinae and Tyrophagus putrescentiae, it was 100 PNU/mL. Threshold concentration for all epidermals except human dander was at least 1250 PNU/mL. The optimal threshold concentration for human dander was 300 PNU/mL. Our results suggest that the currently used 1:100 000 w/v concentration of histamine and the 1000 PNU/mL concentration for most grasses, weeds, trees, moulds, epidermals and insects may not be appropriate for canine intradermal testing.
authors.affiliation: Department of Small Animal Medicine, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602, USA. phensel@vet.uga.edu
authors.forename: Patrick
authors.initials: P
authors.lastname: Hensel
authors.forename: Michaela
authors.initials: M
authors.lastname: Austel
authors.forename: Linda
authors.initials: L
authors.lastname: Medleau
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Anand
authors.initials: A
authors.lastname: Vidyashankar
mesh_terms: D000485:Allergens / Q000276:immunology / Q000494:pharmacology*; D000818:Animals; D003876:Dermatitis, Atopic / Q000139:chemically induced / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis*; D004285:Dogs / Q000276:immunology*; D005260:Female; D006632:Histamine / Q000276:immunology / Q000494:pharmacology*; D007428:Intradermal Tests / Q000379:methods / Q000592:standards / Q000662:veterinary*; D008297:Male; D012016:Reference Values; D012867:Skin / Q000187:drug effects*
chemical_list: D000485:Allergens; D006632:Histamine