Diagnostic specificity of the Fcε-receptor based allergy screening test

Abstract

Summary Objective: To evaluate the diagnostic specificity of a Fcε-receptor allergy screening test using serum from clinically non-atopic dogs. Material and methods: In this prospective study allergen-specific IgE levels were measured using the Fcε-receptor method (Allercept® Heska) in the serum from 15 clinically non-atopic dogs, without any history of pruritic skin diseases or recurrent ear diseases. Five crossbreeds and 10 pure breed dogs were included with approximately equal sex distribution. Their age ranged between 2 and 14 years, with a median age of 4 years. A commercially available allergy screening test was performed evaluating three allergen groups: mites (house dust mites and forage mites), moulds and pollens, as well as flea-saliva. Results: All except one dog showed positive results for at least one of the allergen groups. Fourteen dogs were positive for mites (house dust mites and forage mites), five dogs each were additionally positive for flea-saliva antigen and for pollens, respectively; only one dog was positive for moulds. Overall diagnostic specificity of the allergy screening test was 6.7% for mites, 66.6% for flea-saliva and pollens and 93.3% for moulds. Conclusions: The Fcε-receptor based allergy screening test detects a high incidence of allergen-specific IgE among clinically non-atopic dogs. The low diagnostic specificity in this study confirms results of earlier studies with serological monoclonal and polyclonal allergy testing. Clinical relevance: This Fcε-receptor based allergy screening test should not be used to establish the diagnosis of canine atopic dermatitis. Diagnosis of atopic dermatitis in dogs is based on clinical criteria and exclusion of other causes of pruritus. Positive intradermal or serological allergy testing is only a minor diagnostic criterion. Any kind of allergy testing is performed for identification of the relevant allergens in atopic dogs as a precondition for allergen specific immunotherapy.