Immunodeficiency diseases that should be differentiated from atopic dermatitis

Abstract

Atopic dermatitis is defined as chronic, recurrent, intractable eczema with atopic diathesis. Considering its pathophysiology as the skin irritability and hyperreactivity due to skin barrier disruption represented by FILAGGRIN mutations, atopic dermatitis itself could be a kind of autoinflammatory or immunodeficiency disease. On the other hand, in clinical practice, it is necessary to distinguish without delay atopic dermatitis-like skin symptoms that appear as partial symptoms of distinct primary immunodeficiencies. Immunodeficiency diseases listed in the latest Japanese Guideline for Atopic Dermatitis that need to be differentiated from pediatric atopic dermatitis include Netherton syndrome due to skin barrier disruption, Wiskott-Aldrich syndrome due to impaired cytoskeletal remodeling, hyper-IgE syndrome due to altered cytokine signaling, Omenn syndrome due to T-cell repertoire restriction, and IPEX syndrome due to immune tolerance failure. Understanding the pathophysiology of these "primary atopic diseases" is expected to deepen our understanding of the complex pathophysiology of atopic dermatitis.