Human and computational models of atopic dermatitis: A review and perspectives by an expert panel of the International Eczema Council.

Atopic dermatitis (AD) is a prevalent disease worldwide and is associated with systemic comorbidities representing a significant burden on patients, their families, and society. Therapeutic options for AD remain limited, in part because of a lack of well-characterized animal models. There has been increasing interest in developing experimental approaches to study the pathogenesis of human AD in vivo, in vitro, and in silico to better define pathophysiologic mechanisms and identify novel therapeutic targets and biomarkers that predict therapeutic response. This review critically appraises a range of models, including genetic mutations relevant to AD, experimental challenge of human skin in vivo, tissue culture models, integration of "omics" data sets, and development of predictive computational models. Although no one individual model recapitulates the complex AD pathophysiology, our review highlights insights gained into key elements of cutaneous biology, molecular pathways, and therapeutic target identification through each approach. Recent developments in computational analysis, including application of machine learning and a systems approach to data integration and predictive modeling, highlight the applicability of these methods to AD subclassification (endotyping), therapy development, and precision medicine. Such predictive modeling will highlight knowledge gaps, further inform refinement of biological models, and support new experimental and systems approaches to AD.

Risk of Non-melanoma Skin Cancer in Patients with Atopic Dermatitis Treated with Oral Immunosuppressive Drugs.

There is uncertainty about the risk of developing non-melanoma skin cancer (NMSC), including basal cell carcinoma and squamous cell carcinoma (SCC), in patients with atopic dermatitis (AD) treated with oral immunosuppressive drugs. A total of 557 patients with AD treated with these drugs in the University Medical Center Utrecht and Groningen, the Netherlands, were analysed. NMSC after oral immunosuppressive treatment was reported in 18 patients (3.2%). The standardized incidence ratio for developing SCC was 13.1 (95% confidence interval (95% CI) 6.5-19.7). Patients developing NMSC were older at the start of therapy (p<0.001) and data lock (p<0.001) compared with patients without NMSC. No significant differences were found in sex, cumulative days of oral immunosuppressive drugs and follow-up between these groups (p=0.42, p=0.88, and p=0.34, respectively). In interpreting these results it is important to include other factors, such as lack of association between treatment duration and tumour development and the long interval between treatment discontinuation and tumour development in some patients.

[A woman with hyperpigmentations on the upper legs]. / Een vrouw met hyperpigmentaties op de bovenbenen.

A 35-year-old, pregnant, Caucasian woman presented with symmetric band-like pigmentation lines on the medial side of both upper legs, recognised as pigmentary demarcation lines type B.