Non-invasive assessment of skin vascularization, blood perfusion and micro-morphology in patients with atopic dermatitis and psoriasis

Introduction &amp; Objectives: <br/>Atopic dermatitis and psoriasis are two chronic inflammatory skin diseases that significantly impact the physical, psychological, and social well-being of affected individuals. Inflammation promotes angiogenesis; therefore, these diseases are associated with changes in the skin’s capillary system. Current techniques for studying dermal microvasculature such as capillaroscopy, intravital microscopy and laser Doppler imaging have poor spatial resolution, require exogenous contrast agents, or are limited to specific regions of the body. In this study, we will apply laser speckle contrast imaging (LSCI) and optical coherence tomography angiography (OCTA) to patients with atopic dermatitis and psoriasis. The techniques complement each other and offer non-invasive, high-resolution alternatives to better understand the microstructural and vascular changes in these skin diseases. The full-field technique LSCI maps blood perfusion at the capillary level, while OCTA visualizes 3D dermal microanatomy with micrometer resolution. To the best of our knowledge, investigating atopic dermatitis and psoriasis using a combination of LSCI and OCTA has not been done before.<br/><br/>Materials &amp; Methods: <br/>This feasibility study involves recruiting 10 patients with atopic dermatitis, 10 patients with psoriasis, and 5 healthy control subjects. All participating patients will fill out the Dermatological Quality of Life Index (DQLI) questionnaire and will be assessed by a clinician who will record an Eczema Area and Severity Index (EASI) or Psoriasis Area Severity Index (PASI) score. Additionally, a lesion on the patient’s arm will be scanned using the LSCI and OCTA techniques and will undergo one biopsy (see Fig 1). Subsequently, a non-lesional spot on the patient’s arm will be scanned using the OCTA technique and will also undergo one biopsy. Healthy controls will be scanned with LSCI and OCTA techniques and undergo a biopsy on one arm. The biopsies will consist of four-millimeter punch biopsies and will be used to assess the degree of inflammation and angiogenesis. They will be stained with hematoxylin-eosin for inflammation, and antibodies for CD-31 to measure capillary density in the skin. Additionally, antibodies for aquaporin 3 will be used to investigate the amount of aquaporin 3 present. Measured parameters are correlated with the type and degree of disease.<br/><br/>Results: <br/>Outcomes include the differentiation of dermatological disease states based on microstructural and vascular properties. Quantitative imaging measures are correlated with questionnaire responses, clinician assessment and histological findings. Results will be statistically analyzed using appropriate tests.<br/><br/>Conclusion: <br/>The study demonstrates the potential of combining LSCI and OCTA techniques in disease monitoring, clarifying diagnosis, and complementing or replacing invasive biopsy procedures for assessing skin microvasculature in atopic dermatitis and psoriasis.<br/>