Diagnosis of skin and soft tissue infections using near-infrared spectroscopy

Structural and functional imaging of psoriasis for severity assessment and quantitative monitoring of treatment response using high-resolution optoacoustic imaging

Psoriasis is a chronic inflammatory skin disease, characterized by thick scaly plaques. It imposes a notable disease burden with varying levels of severity affecting the quality of life significantly. Current disease severity assessment relies on semi-objective visual inspection based on the Psoriasis Area and Severity index (PASI) score that might not be sensitive to sub-clinical changes. Histology of psoriasis skin lesions necessitate invasive skin biopsies. This indicates an unmet need for a non-invasive, objective and quantitative approach to assess disease severity serially. Herein, we employ multispectral Raster-Scanning Optoacoustic Mesoscopy (ms-RSOM) derived structural and microvascular functional imaging metrics to examine the lesional and non-lesional skin in psoriasis subjects across different severities and also evaluate the treatment outcome in a subject with topical steroids and biologics, such as adalimumab. ms-RSOM derived structural metrics like epidermal thickness and total blood volume (TBV) and microvascular functional information such as oxygen saturation (sO2) are evaluated by spectrally resolving the endogenous chromophores like melanin, oxy-, and deoxy-hemoglobin. Initial findings reveal an elevated sO2 and TBV with severity in lesional and non-lesional psoriasis skin, thus representing increasing inflammation. An increase in epidermal thickness is also noted with the degree of severity, corresponding to the inflammation and increased abnormal cell growth. As a marker to evaluate the treatment response, we observed a decrease in epidermal thickness, sO2, and TBV in a psoriasis patient post-treatment, which is consistent with the decrease in the PASI score from 4.1 to 1.9. We envision that ms-RSOM has a huge potential to be translated into routine clinical setting for the diagnosis of severity and assessment of treatment monitoring in psoriasis subjects.

Diagnostic methods for the confirmation of non-purulent cellulitis: a review

Cellulitis is the most common cause for skin disease hospitalization with costs totaling over $7 billion. It can be challenging to diagnose due to clinical similarities with other inflammatory conditions and the lack of a gold-standard diagnostic test. This article reviews the different testing methods for the diagnosis of non-purulent cellulitis based on three categories (1) clinical scoring assessments, (2) in vivo imaging techniques, and (3) laboratory assessments.

Multispectral raster-scanning optoacoustic mesoscopy differentiate lesional from non-lesional atopic dermatitis skin using structural and functional imaging markers

Atopic dermatitis (AD) is a chronic and pruritic skin inflammatory disease causing a significant burden to health care management and patient's quality of life. Seemingly healthy skin or non-lesional sites on AD patients still presents skin barrier defects and immune response, which can develop to AD at a later stage. To investigate further the balance between the epidermal barrier impairment and intrinsic immune dysregulation in AD, we exploited multispectral Raster-Scanning Optoacoustic Mesoscopy (ms-RSOM) to image lesional and non-lesional skin areas on AD patients of different severities non-invasively to elucidate their structural features and functional information. Herein, we demonstrate the objective assessment of AD severity using relative changes in oxygen saturation (δsO₂) levels in microvasculature along with other structural parameters such as relative changes in epidermis thickness (δET) and total blood volume (δTBV) between the lesional and non-lesional areas of the skin. We could observe an increasing trend for δsO₂ and δTBV, which correlated well with the subjective clinical Scoring Atopic Dermatitis (SCORAD) for evaluating the severity. Notably, δET showed a decreasing trend with AD severity, indicating that the difference in epidermal thickness between lesional and non-lesional area of the skin decreases with AD severity. Our results also correlated well with conventional metrics such as trans-epidermal water loss (TEWL) and erythrosine sedimentation rate (ESR). We quantified the δsO₂ and δET changes to objectively evaluate the treatment response before and four months after treatment using topical steroids and cyclosporine in one severe AD patient. We observed reduced δsO₂ and δET post treatment. We envision that in future, functional and structural imaging metrics derived from ms-RSOM can be translated as objective markers to assess and stratify the severity of AD and understand the function of skin barrier dysfunctions and immune dysregulation. It could also be employed to monitor the treatment response of AD in regular clinical settings.