Our data reinforce the role of an altered skin barrier in the pathogenesis of AD. Our results show not only reduced expression of filaggrin and claudin 1 in lesional atopic skin but also inverse correlation of filaggrin expression and disease severity. Moreover, elevation of in situ IL-17 and of circulating interleukin levels in AD emphasize the systemic, inflammatory profile of this defective skin barrier dermatosis.

Atopic dermatitis is a chronic inflammatory skin disease with a complex pathogenesis, where changes in skin barrier and imbalance of the immune system are relevant factors. The skin forms a mechanic and immune barrier, regulating water loss from the internal to the external environment, and protecting the individual from external aggressions, such as microorganisms, ultraviolet radiation and physical trauma. Main components of the skin barrier are located in the outer layers of the epidermis (such as filaggrin), the proteins that form the tight junction (TJ) and components of the innate immune system. Recent data involving skin barrier reveal new information regarding its structure and its role in the mechanic-immunological defense; atopic dermatitis (AD) is an example of a disease related to dysfunctions associated with this complex.

BACKGROUND Atopic dermatitis is a highly prevalent inflammatory and pruritic dermatosis with a multifactorial etiology, which includes skin barrier defects, immune dysfunction, and microbiome alterations. Atopic dermatitis is mediated by genetic, environmental, and psychological factors and requires therapeutic management that covers all the aspects of its complex pathogenesis. OBJECTIVES The aim of this article is to present the experience, opinions, and recommendations of Brazilian dermatology experts regarding the therapeutic management of atopic dermatitis. METHODS Eighteen experts from 10 university hospitals with experience in atopic dermatitis were appointed by the Brazilian Society of Dermatology to organize a consensus on the therapeutic management of atopic dermatitis. The 18 experts answered an online questionnaire with 14 questions related to the treatment of atopic dermatitis. Afterwards, they analyzed the recent international guidelines on atopic dermatitis of the American Academy of Dermatology, published in 2014, and of the European Academy of Dermatology and Venereology, published in 2018. Consensus was defined as approval by at least 70% of the panel. RESULTS/CONCLUSION The experts stated that the therapeutic management of atopic dermatitis is based on skin hydration, topical anti-inflammatory agents, avoidance of triggering factors, and educational programs. Systemic therapy, based on immunosuppressive agents, is only indicated for severe refractory disease and after failure of topical therapy. Early detection and treatment of secondary bacterial and viral infections is mandatory, and hospitalization may be needed to control atopic dermatitis flares. Novel target-oriented drugs such as immunobiologicals are invaluable therapeutic agents for atopic dermatitis.

Atopic dermatitis (AD) is a chronic and inflammatory skin disease with intense pruritus and xerosis. AD pathogenesis is multifactorial, involving genetic, environmental, and immunological factors, including the participation of Staphylococcus aureus. This bacterium colonizes up to 30–100% of AD skin and its virulence factors are responsible for its pathogenicity and antimicrobial survival. This is a concise review of S. aureus superantigen-activated signaling pathways, highlighting their involvement in AD pathogenesis, with an emphasis on skin barrier disruption, innate and adaptive immunity dysfunction, and microbiome alterations. A better understanding of the combined mechanisms of AD pathogenesis may enhance the development of future targeted therapies for this complex disease.

IgG of AD patients can stimulate cytokine production in infant thymocytes and thus resembles the peripheral profile observed in adults. These findings suggest a novel mechanism that can contribute to AD pathogenesis.