Canine atopic dermatitis: systemic immunomodulatory protocol based on clinical phenotype

ABSTRACT: 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.

摘要：犬特应性皮炎（canine atopic dermatitis, cAD）是一种多因素过敏性疾病，与免疫功能异常及皮肤屏障功能异常密切相关。多种免疫介质参与其发病机制。此类免疫介质由辅助T淋巴细胞（T helper lymphocytes, Th）经向Th1型和/或Th2型极化激活后产生，进而介导不同的皮损类型。急性皮损由Th2型细胞因子轴激活所介导，临床上可引发红斑与瘙痒症状；反之，慢性皮损则出现Th1/Th2型细胞因子混合免疫应答，最终导致皮肤色素沉着过度及苔藓样变。深入理解此类皮损类型及免疫调节剂的作用机制，对于犬特应性皮炎患犬的最佳临床管理至关重要。基于此背景，本综述探讨了免疫应答及免疫调节药物在犬特应性皮炎患犬中的作用，并提出了基于临床表型的治疗方案。基于本综述呈现的研究证据，靶向与犬特应性皮炎临床表型相关细胞因子谱的免疫调节药物为适宜的治疗选择。