Response to immunotherapy in six related horses with urticaria secondary to atopy

Abstract

Six related (sire and 5 offspring) Arabian horses were examined because of urticaria. In all 6 horses, the urticaria appeared to be a result of inhalant allergies, and all 6 horses responded to immunotherapy, using vaccines containing antigens selected on the basis of results of intradermal testing. For the sire, results of 4 ELISA for serum IgE directed against various allergens were contradictor, and immunotherapy performed using a vaccine containing antigens selected on the basis of results of 1 of these ELISA did not result in any improvement. Clinical signs resolved with immunotherapy, using a vaccine containing antigens selected on the basis of results of intradermal testing, suggesting that results of intradermal testing may be more reliable than results of ELISA for serum IgE when designing immunotherapy protocols for use in horses.