The ACVD task force on canine atopic dermatitis (XXI): antihistamine pharmacotherapy

Antihistamines frequently are recommended by veterinary dermatologists for symptomatic treatment of pruritus associated with canine atopic dermatitis (AD), perhaps because of their moderate success in some human patients with AD. A critical review of the literature describing antihistamine use in ca nine AD reveals that the majority of published, peer-reviewed studies are o pen, uncontrolled or partially-controlled trials. Such studies vary widely in reported efficacy, from perhaps 0 to 75% of patients, even using the sam e drug. The few blinded placebo-controlled trials available have failed to confirm efficacy of these drugs to relieve the pruritus of canine AD. Some studies indicate that synergistic effects could occur with concurrent use o f essential fatty acid supplements. Consequently, at the time of this writi ng, there is insufficient evidence to conclude for or against the efficacy of antihistamines for treatment of canine AD. Additional blinded, randomize d and controlled trials with larger numbers of patients are necessary to es tablish which of the antihistamine drugs currently available, if any, are t ruly efficacious for canine AD. Nevertheless, present clinician consensus s uggests that several different antihistamine drugs should be evaluated in s equence, for 7-14 days each, in canine patients with AD. (C) 2001 Elsevier Science B.V. All rights reserved.