A pilot study of the validation of percutaneous testing in cats

• Published in: Veterinary dermatology 2013-10, Vol.24 (5), p.488-e115
• Main Authors: Rossi, Michael A., Messinger, Linda, Olivry, Thierry, Hoontrakoon, Raweewan
• Format: Article
• Language: English
• Subjects: Allergens - immunology; Animals; Cat Diseases - diagnosis; Cat Diseases - immunology; Cats; Dermatitis, Atopic - diagnosis; Dermatitis, Atopic - immunology; Dermatitis, Atopic - veterinary; Female; Histamine - immunology; Hypersensitivity - diagnosis; Hypersensitivity - veterinary; Intradermal Tests - veterinary; Male; Pilot Projects; Sensitivity and Specificity; Skin - drug effects; Skin - immunology; Skin Tests - methods; Skin Tests - veterinary
• ISSN: 0959-4493; 1365-3164
• DOI: 10.1111/vde.12054

Background Intradermal testing is useful for the identification of environmental allergens to which cats could be hypersensitive; intradermal test reactions are often subtle and difficult to interpret in cats. Percutaneous testing is the standard technique for the detection of significant environmental allergens in people, but it has not yet been evaluated in cats with hypersensitivity dermatitis. Hypothesis/Objectives The purpose of this study was to evaluate and compare the skin test responses of healthy cats to percutaneous application and intradermal injections of control solutions. Methods Ten clinically healthy cats were studied. Percutaneous applications of 0.0275 and 0.1 mg/mL aqueous histamine, 6 mg/mL glycerinated histamine, 0.9% buffered saline and 50% glycerosaline solution were performed using Greer Pick (Greer Laboratories, Lenoir, NC, USA) and Duotip‐Test II (Lincoln Diagnostics, Decatur, IL, USA) percutaneous applicators. Reactions were compared with intradermal injections of 0.0275 mg/mL aqueous histamine and 0.9% buffered saline as controls. Results Positive responses to histamine solutions were significantly greater with the Greer Pick than with the Duotip‐Test II. There were no significant differences between the histamine reactions using the Greer Pick applicator and the intradermal injections. Percutaneous reactions to histamine were more well demarcated and easier to read than intradermal injection reactions. Reactions to the saline controls were not noted. Conclusions and clinical importance Percutaneous application of 6 mg/mL glycerinated histamine solution, 50% glycerosaline solution and 0.9% buffered saline produced similar positive and negative control wheals. These observations warrant further studies of percutaneous allergen testing in cats with hypersensitivity dermatitis. Résumé Contexte Les tests intradermiques sont utiles pour l'identification des allergènes environnementaux auxquels les chats pourraient être sensibilisés; les intradermoréactions sont souvent subtiles et difficiles à interpréter chez le chat. Les tests percutanés sont la technique standard de détection des allergènes environnementaux significatifs chez l'homme mais n'ont pas encore été évalués chez les chats atteints de dermatite par hypersensibilité. Hypothèses/Objectifs Le but de cette étude était d'évaluer et de comparer les réponses aux tests cutanés de chats sains à l'application percutanée et aux injections intradermiques de solutions de contrôle. Mé