The ACVD task force on canine atopic dermatitis (XII): the relationship ofcutaneous infections to the pathogenesis and clinical course of canine atopic dermatitis

Dogs and human beings with atopic dermatitis (AD) frequently exhibit concur rent skin infections with Staphylococcus sp. bacteria or Malassezia yeast, and treatment of such infections is an important facet of managing these pa tients. Staphylococci appear to colonize atopic skin readily, and bacterial products on the skin could augment cutaneous inflammation via immediate hy persensitivity responses to the bacteria, by superantigen-mediated lymphocy te activation, or other non-specific mechanisms. Similarly, skin colonizati on by Malassezia yeast could contribute to clinical signs of AD; yeast comp onents could induce inflammation via non-specific mechanisms, such as alter ation in mediator release, or via antigen-specific hypersensitivity reactio ns. Clinical and experimental evidence exists that secondary microbial infe ctions can both initiate and perpetuate episodes of AD in dogs and humans, and could even participate in promotion of pro-allergic immunologic respons es. Mechanistic details of these complex interactions are under extensive i nvestigation in human beings; only a few observations have been extended to include dog with AD. (C) 2001 Elsevier Science B.V. All rights reserved.