Factors Influencing Margin Clearance and the Number of Stages of Mohs Micrographic Surgery in Basal Cell Carcinoma: A Retrospective Chart Review.

How patient and tumor factors influence clearance margins and the number of Mohs Micrographic Surgery (MMS) stages when treating basal cell carcinoma (BCC) remains widely uncharacterized. It is important to elucidate these relationships, as surgical outcomes may be compared nationally between colleagues. Our objective is to evaluate the relationships between defect size and patient demographics, as well as between BCC subtypes and the number of MMS stages. Our second objective is to compare practice patterns and characteristics of patients requiring MMS at academic centers and private practices. A retrospective chart review was performed using data collected at academic centers (2015-2018) and private practices (2011-2018) of BCC patients older than 18 years old who underwent MMS. In total, 7651 patients with BCC requiring MMS were identified. Academic center adjusted analyses demonstrated clearance margins 0.1 mm higher for every year's increase in age (p < 0.0001) and 0.25 increase in MMS stages for high-risk BCC (p < 0.0001). Private practice adjusted analyses demonstrated clearance margins 0.04 mm higher for every year's increase in age (p < 0.0001). Clearance margins correlate with older age, and additional MMS stages correlate with high-risk BCC, suggesting the role patient and tumor factors may play in predicting tumor clearance and MMS stages.

Energy-based devices in the treatment of acne scars in skin of color.

BACKGROUND: Acne scarring is disfiguring and psychologically taxing on patients. Many energy-based modalities have emerged and been studied for the treatment of acne scarring; however, there is a paucity of these studies in skin phototypes IV-VI. OBJECTIVE: To review the medical literature and discuss the most significant studies regarding safety and efficacy of energy-based devices (ablative lasers, non-ablative lasers, and radiofrequency microneedling) in the treatment of ethnic skin (skin phototypes IV-VI). METHODS: A literature search was conducted using the PubMed database and bibliographies of relevant articles. RESULTS: Ablative and non-ablative lasers have proven to be effective for treatment of acne scars in ethnic skin. The risk of developing adverse effects such as post-inflammatory hyperpigmentation is contingent upon several factors including skin phototype, laser device, fluence, and moreso density settings. Non-ablative fractional lasers have been considered first line for the treatment of acne scars in skin of color due to their better safety profile; however, they are less efficacious and require more treatments compared to ablative lasers. Studies regarding efficacy and safety of radiofrequency microneedling for treatment of acne scarring in skin of color are limited, but are promising. CONCLUSION: Ablative lasers, non-ablative lasers, and radiofrequency microneedling are all useful treatments for acne scarring in ethnic skin when appropriate settings are used. Further head-to-head studies are needed to evaluate their efficacy and safety in darker skin phototypes V-VI.

Psoriasiform Dermatitis in a COVID-19 Patient.

Psoriasis is a chronic inflammatory papulosquamous disorder which affects around 2% of the world's population. A peak exacerbation in psoriatic symptoms was noted during COVID-19 due to lack of access to dermatological care mixed with heightened emotional stress during the pandemic. This case report describes a 52-year-old admitted male patient who sustained a diffuse rash on multiple areas of his body a week prior to testing positive for COVID-19. We explore plausible causes for the occurrence of the rash, discuss our treatment plan, include relevant clinical pictures, and review published literature to examine conditions that present similarly to the rash seen in our patient. It is crucial for dermatologists to be able to discern various systemic manifestations associated with cutaneous lesions, such as the one seen in this patient, in order to make an accurate and prompt diagnosis. A better understanding of the association between COVID-19 infection and psoriasiform lesions is needed for improving the prognostic and therapeutic outcomes in patients.

ZO-1 protein is required for hydrogen peroxide to increase MDCK cell paracellular permeability in an ERK 1/2-dependent manner.

Hydrogen peroxide (H2O2) increases paracellular permeability of Madin-Darby canine kidney (MDCK) cells, but the mechanism mediating this effect remains unclear. Treatment of MDCK cells with H2O2 activated ERK 1/2. Inhibition of ERK 1/2 activation blocked the ability of H2O2 to increase paracellular permeability. Knockdown of zonula occludens-1 (ZO-1) protein but not occludin eliminated the ability of H2O2 to increase paracellular permeability. H2O2 treatment did not, however, affect the total cell content or contents of the Triton X-100-soluble and -insoluble fractions for occludin, ZO-1, or ZO-2. H2O2 treatment decreased the number of F-actin stress fibers in the basal portion of the cells. Similar to wild-type MDCK cells, H2O2 increased ERK 1/2 activation in ZO-1 knockdown and occludin knockdown cells. Inhibition of ERK 1/2 activation blocked the increase in paracellular permeability in occludin knockdown cells. ZO-1 knockdown cell paracellular permeability was regulated by PP1, an src inhibitor, indicating that the loss of response to H2O2 was not a general loss of the ability to regulate the paracellular barrier. Inhibition of myosin ATPase activity with blebbistatin increased paracellular permeability in ZO-1 knockdown cells but not in wild-type MDCK cells. H2O2 treatment sensitized wild-type MDCK cells to inhibition of myosin ATPase. Knockdown of TOCA-1 protein, which promotes formation of local branched actin networks, reproduced the effects of ZO-1 protein knockdown. These results demonstrate that H2O2 increases MDCK cell paracellular permeability through activation of ERK 1/2. This H2O2 action requires ZO-1 protein and TOCA-1 protein, suggesting involvement of the actin cytoskeleton.