Efficacy of laser hair removal in hidradenitis suppurativa: A systematic review and meta-analysis.

OBJECTIVES: Hidradenitis suppurativa (HS) is a chronic inflammatory condition characterized by painful nodules, draining tunnels, and fibrotic scarring in intertriginous, hair-bearing areas. The pathogenesis involves follicular occlusion and subsequent rupture, leading to uncontrolled inflammation. Treatment options for HS are limited and lack universal effectiveness. Laser hair removal (LHR) has been explored as a potential treatment; however, the efficacy and appropriate laser modalities remain unclear. This systematic review examined the efficacy and adverse effects of LHR in HS. METHODS: A comprehensive literature search was conducted from inception to September 2023 in Ovid MEDLINE, Ovid Embase, and The Cochrane Library (Wiley) with predefined inclusion and exclusion criteria, and a meta-analysis was conducted. RESULTS: Ten studies were selected (n = 227 total patients) and included six randomized controlled trials, two nonrandomized experimental studies, and two case series. Various laser modalities, including long-pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) (n = 115), intense pulsed light (n = 18), Alexandrite (n = 54), intralesional 1064 nm diode (n = 20), and combined fractional CO2 and long-pulsed Nd:YAG laser (n = 20), consistently demonstrated significant improvement in HS disease severity, irrespective of the disease scoring method used. Minimal adverse effects (primarily mild pain and erythema) were reported. A meta-analysis of three studies utilizing long-pulsed Nd:YAG laser demonstrated a standardized mean difference in disease severity of -1.68 (95% confidence interval: -2.99; -0.37), favoring treatment with LHR for HS. CONCLUSIONS: Hair follicles are key in HS pathogenesis and all included studies showed a significant improvement in HS disease severity after LHR regardless of the laser device used, likely related to hair follicle unit destruction. HS is a complex and heterogenous condition, and multiple disease scoring methods complicate outcome comparisons across studies. However, LHR, utilizing various techniques, is an effective treatment option for HS with minimal adverse effects.

Oncogenic Kras induces spatiotemporally specific tissue deformation through converting pulsatile into sustained ERK activation.

Tissue regeneration and maintenance rely on coordinated stem cell behaviours. This orchestration can be impaired by oncogenic mutations leading to cancer. However, it is largely unclear how oncogenes perturb stem cells' orchestration to disrupt tissue. Here we used intravital imaging to investigate the mechanisms by which oncogenic Kras mutation causes tissue disruption in the hair follicle. Through longitudinally tracking hair follicles in live mice, we found that KrasG12D, a mutation that can lead to squamous cell carcinoma, induces epithelial tissue deformation in a spatiotemporally specific manner, linked with abnormal cell division and migration. Using a reporter mouse capture real-time ERK signal dynamics at the single-cell level, we discovered that KrasG12D, but not a closely related mutation HrasG12V, converts ERK signal in stem cells from pulsatile to sustained. Finally, we demonstrated that interrupting sustained ERK signal reverts KrasG12D-induced tissue deformation through modulating specific features of cell migration and division.

Injury prevents Ras mutant cell expansion in mosaic skin.

Healthy skin is a mosaic of wild-type and mutant clones1,2. Although injury can cooperate with mutated Ras family proteins to promote tumorigenesis3-12, the consequences in genetically mosaic skin are unknown. Here we show that after injury, wild-type cells suppress aberrant growth induced by oncogenic Ras. HrasG12V/+ and KrasG12D/+ cells outcompete wild-type cells in uninjured, mosaic tissue but their expansion is prevented after injury owing to an increase in the fraction of proliferating wild-type cells. Mechanistically, we show that, unlike HrasG12V/+ cells, wild-type cells respond to autocrine and paracrine secretion of EGFR ligands, and this differential activation of the EGFR pathway explains the competitive switch during injury repair. Inhibition of EGFR signalling via drug or genetic approaches diminishes the proportion of dividing wild-type cells after injury, leading to the expansion of HrasG12V/+ cells. Increased proliferation of wild-type cells via constitutive loss of the cell cycle inhibitor p21 counteracts the expansion of HrasG12V/+ cells even in the absence of injury. Thus, injury has a role in switching the competitive balance between oncogenic and wild-type cells in genetically mosaic skin.

Truncal Acne and Scarring: A Comprehensive Review of Current Medical and Cosmetic Approaches to Treatment and Patient Management.

Acne vulgaris is one of the most common skin disorders worldwide. It typically affects skin areas with a high density of sebaceous glands such as the face, upper arms, chest, and/or back. Historically, the majority of research efforts have focused on facial acne vulgaris, even though approximately half of patients with facial lesions demonstrate truncal involvement. Truncal acne vulgaris is challenging to treat and poses a significant psychosocial burden on patients. Despite these characteristics, studies specifically examining truncal acne vulgaris are limited, with treatment guidelines largely derived from facial protocols. Therefore, truncal acne remains an understudied clinical problem. Here, we provide a clinically focused review on the epidemiology, evaluation, and available treatment options for truncal acne vulgaris. In doing so, we highlight knowledge gaps with the goal of spurring further investigation into the management of truncal acne vulgaris.

The Association of Academic Cosmetic Dermatology: improving cosmetic dermatology education through collaboration, research, and advocacy.

Cosmetic and laser procedures are increasingly popular among patients and are skills in which dermatologists are regarded as well trained. Most dermatology residents intend to incorporate cosmetic procedures into their practice and prefer to learn such procedures during residency through direct patient care. However, there are notable challenges in optimizing how residents are trained in cosmetic and laser dermatology. To address these barriers and elevate the practice of cosmetic dermatology in academic medicine, the Association of Academic Cosmetic Dermatology (AACD) was founded in 2021 as the lead professional society for dermatologists who direct the education of resident trainees in cosmetic and laser dermatology. The AACD, a group of board-certified dermatologists who teach cosmetic and laser dermatology to residents, aims to improve cosmetic dermatology education through collaboration, research, and advocacy.

Needs and Gaps in Resident Trainee Education, Clinical Patient Care, and Clinical Research in Cosmetic Dermatology: Position Statement of the Association of Academic Cosmetic Dermatology.

Cosmetic dermatology is a key subspecialty of academic dermatology. As such, academic centers are expected to demonstrate excellence in the teaching of cosmetic dermatology skills to trainees, the clinical delivery of cosmetic dermatology services to patients, and the performance of clinical research that advances knowledge and uncovers new therapies in cosmetic dermatology. The Association of Academic Cosmetic Dermatology (AACD), a newly formed medical professional society, includes as its principal aims the support of all of these areas. AACD is comprised of group of board-certified dermatologists who teach cosmetic and laser dermatology at US dermatology residency programs. An expert panel constituted by the AACD recently convened a workshop to review gaps pertaining to academic cosmetic dermatology. This panel considered needs and potential corrective initiatives in three domains: resident education, patient experience, and clinical research. The work of the panel was used to develop a roadmap, which was adopted by consensus, and which will serve to guide the AACD moving forward.

Factors affecting outcomes of second intent healing of nasal defects after Mohs micrographic surgery.

Reconstruction of nasal defects secondary to Mohs micrographic surgery (MMS) presents particular challenges related to the complex topography, skin quality, tissue laxity, and functional and aesthetic concerns of the region. Factors affecting outcomes resulting from second intent healing (SIH) on the nose have not been well described. The purpose of the study was to identify factors impacting outcomes of SIH for nasal tumors following MMS. Retrospective analysis was performed of all nasal lesions treated with MMS followed by SIH from a single surgical center over a 1.5-year period. Ninety-six cases were included. Chart review was performed, and data were collected including age, gender, nasal site, tumor type, defect size, depth, and number of MMS stages. Pre- and post-operative follow-up photographs were available for all cases. All five authors evaluated the photographs using the modified Manchester scar scale. Analysis was then conducted to identify features associated with good outcomes. Of the 96 tumors, 39 lesions (40.6%) were located on the nasal tip (including supratip), 32 (33.3%) on the ala/alar groove, 17 (17.7%) on the sidewall, and 8 (8.3%) on the dorsum. The average defect size was 0.83 cm2 (diameter of 1.06 cm ± 0.4). Defect diameter and defect depth were the factors that significantly impacted scar outcome (p < 0.001) in multivariate analysis. No significant functional deficits were reported. This retrospective study suggests that nasal defects with area less than 0.83 cm2 (or 1.06 cm diameter) and depth of defect not extending beyond the superficial fat healed well by SIH regardless of location on the nose.

Meeting Dermatologic Needs in an Uninsured Population: Lessons Learned from a Referrals Cohort at a Student-Run Free Clinic.

Unmet dermatologic needs of the uninsured patient population are important to identify and address, especially as the COVID-19 pandemic has introduced additional barriers of access to care. We describe the successful collaboration between a student-run free clinic and dermatology practice since 2012, highlighting excellent time to appointment intervals and resolution rates as well as the associated modest financial cost. We believe that the information provided in our report may serve as a proof of concept and facilitate the implementation of such collaborations throughout the United States.

A Histopathologic Scoring System for Perineural Invasion Correlates With Adverse Outcomes in Patients With Cutaneous Squamous Cell Carcinoma.

BACKGROUND: Perineural invasion (PNI) is a known risk factor for recurrence, metastasis, and death in cutaneous squamous cell carcinoma (cSCC). Current staging systems include PNI, but none define its extent or severity. OBJECTIVE: To identify histopathologic features of cSCC with PNI that may be associated with adverse outcomes. MATERIALS AND METHODS: This is a retrospective cohort study that included 45 patients with cSCC and PNI treated with surgical excision. Histopathologic slides were analyzed for 5 features of PNI: largest affected nerve diameter, number of nerves affected, depth of nerve involvement, intra- versus extratumoral PNI, and focal versus circumferential PNI. RESULTS: The median largest affected nerve diameter was 0.13 mm, and the median number of nerve structures involved was 4. After a median follow-up time of 24 months, 6 patients developed adverse outcomes, including 2 local recurrences, 4 metastases, and 2 tumor-related deaths. Univariate logistic regression analysis revealed that nerve diameter and number of affected nerves were significantly associated with adverse outcome. A composite PNI score, calculated from 5 histopathologic features, was the strongest predictor of adverse outcome (p = .020). CONCLUSION: Histopathologic features of PNI can be quantified with a composite PNI score that is significantly associated with adverse outcomes in cSCC.

Predicting outcomes following second intent healing of periocular surgical defects.

BACKGROUND: Traditionally, second intent healing (SIH) in the periocular region is reserved for small and/or concave defects, particularly those located on the medial canthus. AIM: The purpose of this study was to identify factors impacting outcomes of SIH for periocular tumors following Mohs micrographic surgery (MMS). METHODS: Retrospective analysis was performed of all periocular lesions treated with MMS followed by SIH from a single academic surgical center over a 5-year period. Data regarding tumor characteristics and follow-up was recorded. The modified Manchester scale was utilized to evaluate scar outcomes. RESULTS: Of the 39 tumors included, 14 (35.9%) were located on the lower eyelid, 12 (30.8%) on the upper eyelid, 6 (15.4%) on the lateral canthus, and 7 (17.9%) on the medial canthus. Involvement of the eyelid margin was seen in 11 (28.2%) of cases. The average defect diameter and area were 1.3 cm and 1.04 cm-squared. Twenty-three cases (59.0%) healed with optimal results. Larger defects were significantly associated with poorer outcomes of SIH (odds ratio 0.205, p = 0.017 by multivariate analysis). Anatomic location, involvement of the lid margin, age, and follow-up interval were not significant factors; however, medial canthus defects were least likely to heal with optimal results. On average, medial canthal lesions were larger in size (mean diameter 1.76 cm, mean area 1.97 cm-squared). CONCLUSIONS: This retrospective study suggests that periorbital defects in all locations with area less than 1.04 cm2 heal well by SIH. In this cohort, larger lesions on the medial canthus healed with worse outcomes.

Hair follicle regeneration suppresses Ras-driven oncogenic growth.

Mutations associated with tumor development in certain tissues can be nontumorigenic in others, yet the mechanisms underlying these different outcomes remains poorly understood. To address this, we targeted an activating Hras mutation to hair follicle stem cells and discovered that Hras mutant cells outcompete wild-type neighbors yet are integrated into clinically normal skin hair follicles. In contrast, targeting the Hras mutation to the upper noncycling region of the skin epithelium leads to benign outgrowths. Follicular Hras mutant cells autonomously and nonautonomously enhance regeneration, which directs mutant cells into continuous tissue cycling to promote integration rather than aberrancy. This follicular tolerance is maintained under additional challenges that promote tumorigenesis in the epidermis, including aging, injury, and a secondary mutation. Thus, the hair follicle possesses a unique, enhanced capacity to integrate and contain Hras mutant cells within both homeostatic and perturbed tissue, demonstrating that in the skin, multiple, distinct mechanisms exist to suppress oncogenic growth.