Evaluation of a point-of-care immunodot assay for predicting results of allergen-specific intradermal and immunoglobulin E serological tests

Immunotherapy to prevent recurrence of clinical signs of atopic dermatitis (AD) is based on intradermal or serological tests that assist in identifying allergen-specific immunoglobulin E hypersensitivities. Unfortunately, the results of such tests can be negatively influenced by several factors, which include the age of the patients, the season of testing and the administration of anti-allergic drugs. Screening to predict when these expensive tests will be useful would benefit owners of dogs with AD. The objectives of this study were to determine whether a point-of-care allergen-specific immunodot assay (Allercept E-Screen (c), Heska Corp., Ft Collins, CO, USA) could predict results of either intradermal or Allercept (c) full panel serological tests in atopic dogs. Thirty dogs living in the south-eastern USA were diagnosed with AD in accordance with current standards. Allergen-specific intradermal, serological and E-Screen (c) tests were performed in all subjects. For flea, house dust mite and pollen allergens altogether, results of the E-Screen (c) assay agreed with those of intradermal and serological tests in 26/30 dogs (87%) and 25/30 dogs (83%), respectively. In this group of dogs, the probabilities of obtaining intradermal or serological tests positive for these allergens were 70 and 67%, respectively. If either skin or serum tests were performed only in dogs with positive E-Screen (c) tests, the probability of obtaining positive results would be increased from 70 to 95% and from 67 to 90%, respectively. In this population of dogs with AD, results of the E-Screen (c) point-of-care immunodot assay was found to often agree with those of allergen-specific intradermal or Allercept (c) tests for selected allergen groups.