853 A novel expression based, non-invasive method to differentiate atopic dermatitis and psoriasis

Psoriasis and atopic dermatitis (AD) are two of the most prevalent chronic inflammatory skin diseases in world. Currently, diagnosis psoriasis AD is conferred based on combination a visual exam review medical history. In some instances, overlapping clinical characteristics disease manifestations make it difficult to distinguish between AD, so biopsy collected for pathological analysis. While effective, biopsies invasive have potential complications dermatological already characterized by abnormalities barrier. Here, we describe non-invasive method differentiate comparing expression key genes involved pathogenesis psoriasis. Epidermal samples were non-invasively from patients with moderate severe (n=20) or using DermTech Smart Sticker™. RNA was isolated analyzed quantitative real-time PCR IL-13, IL-23, IL-17A, S100A8, S100A9, CXCL9, CXCL10, CCL17, CCL18, CCL27, TLSP, NOS2. Upregulation NOS2 exhibited greatest differences AD. When combined, Receiver Operating Characteristic (ROC) Curve analysis data set generated an AUC 0.94 that can be used conditions. Overall, this study demonstrates utility sampling molecular signature four genes. The ability conditions provides valuable asset hands physicians decision-making utilized personalized treatment patients.