We demonstrated a simple and more precise method to quantify and compare facial skin erythema by analyzing the RGB channel values of the VISIA Red images. Our method brings convenience for erythema evaluation in dermatological studies.

Background: The ultraviolet-induced red fluorescence (UVRF) from human skin follicles was suggested to be a result of Propionibacterium acnes and was used for the monitoring of acne. More recent studies suggested that the UVRF may be more related to sebum rather than to microorganisms. Objective: To clarify whether human sebum or follicular microorganisms are the source of UVRF. Methods: We examined the fluorescence of human-derived SZ95 sebocytes, human sebaceous glands, sebum extracted from the sebaceous glands, and bacteria isolated from human hair follicles under ultraviolet light. Results: SZ95 sebocytes, human sebaceous glands, and sebum do not emit UVRF. Two types of UVRF peaking at about 635 nm and at about 620 nm were detected in P. acnes and Staphylococcus epidermidis, respectively. This is the first report that S. epidermidis emits UVRF when it is anaerobically cultured and then exposed to air. Conclusion: Human follicular UVRF is emitted by resident bacteria, not by sebum. Therefore, UVRF may be used to monitor certain species of skin microorganisms.

Objectives-The purpose of this study was to investigate the performance of ultrasound biomicroscopy (UBM) and high-frequency ultrasound (HFUS) in the assessment of extramammary Paget disease (EMPD) and to correlate the imaging features with pathologic findings.Methods-In this retrospective study, we described the imaging features from UBM and HFUS based on 17 pathologically proven EMPD cases. The performance for visualizing layer involvement by UBM and HFUS was compared. Additionally, we checked the consistency between layer involvement of the lesions on UBM images and the pathologic results. Additionally, blood flow and the status of lymph nodes were investigated with HFUS.Results-Ultrasound biomicroscopy revealed that all 17 lesions (100%) were hypoechoic and grew in a creeping form. The feature of layer involvement was shown in 10 lesions (58.8%) limited to the epidermis and 6 lesions (35.3%) involving the dermis, and the remaining lesion (5.9%) involved the full skin layers. Layer involvement was clearly displayed by UBM for all lesions (100%) but for only 5 lesions (29.4%) by HFUS (P < .001). Additionally, the layer involvement of 15 lesions (88.2%) on UBM was consistent with the pathologic results (κ = 0.746). High-frequency ultrasound revealed profuse blood flow in most lesions (64.7% [11 of 17]), and 1 case showed inguinal lymph node metastasis.Conclusions-Combined use of UBM and HFUS can provide key information on EMPD based on ultrasound features. Comparatively, UBM provides clearer morphologic information, whereas HFUS provides information on lymph node metastasis and blood flow.