Canine atopic dermatitis: systemic immunomodulatory protocol based on clinical phenotype

Canine atopic dermatitis (cAD) is a multifactorial allergic disease associated with immune dysfunction and abnormal skin barrier. Several immunological mediators play a role in its pathogenesis. Such molecules are produced by the activation of T helper lymphocytes (Th) through polarization to Th1 and/or Th2, which contributes to different lesion patterns. Acute lesions are mediated by an activation of the Th2 cytokine axis, which clinically induces erythema and pruritus. Conversely, in chronic injuries a mixed immune response of Th1/Th2 cytokines occurs, leading to hyperpigmented and lichenified skin. The clinical understanding of these patterns and the mode of action of immunomodulators are crucial for the best clinical management of the atopic patient. In this context, this review discussed the role of the immune response and the immunomodulatory drugs in dogs with atopic dermatitis and suggested a therapeutic protocol based on clinical phenotype. Based on the evidences showed in this review, it is considered appropriate to use immunomodulatory drugs that target cytokine spectrum related with the clinical phenotype of cAD.