The role of in vivo reflectance confocal microscopy for the management of acne: A systematic review.

Acne diagnosis, severity assessment and treatment follow-up rely primarily on clinical examination. In vivo reflectance confocal microscopy (RCM) provides non-invasively, real-time images of skin lesions with a level of detail close to histopathology. This systematic literature review aims to provide an overview of RCM utility in acne and a summary of specific features with clinical application that may increase objectivity in evaluating this condition. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting our results. We systematically searched three databases: PubMed, Clarivate and Google Scholar (January 2022). All included studies used RCM to investigate acne in human patients and reported the investigated skin area and type (acne lesions or clinically uninvolved skin), the substance used in the case of treatment. Our search identified 2184 records in the three databases investigated. After duplicate removal, 1608 records were screened, 35 were selected for full-text assessment, and 14 were included in this review. We used the QUADAS-2 tool to evaluate the risk of bias and applicability concerns. RCM was selected as the index test and clinical examination as the reference standard. The total number of patients from all studies was 291, with 216 acne patients and 60 healthy participants aged between 13 and 45 years. The 14 considered studies analysed 456 follicles from healthy participants, 1445 follicles from uninvolved skin in acne patients and 1472 acne lesions. Consistent RCM findings concerning follicles of acne patients reported across studies were increased follicular infundibulum size, thick, bright border, intrafollicular content and inflammation. Our analysis indicates that RCM is a promising tool for acne evaluation. Nevertheless, standardization, a unified terminology, consistent research methods and unitary reporting of RCM findings are necessary. PROSPERO registration number CRD42021266547.

Deciphering gynaecological pathologies in women with acne and alopecia: an imaging experience.

Polycystic ovarian syndrome manifests acne and alopecia in teenagers and young adult females. To evaluate ovarian morphology and the prevalence of polycystic ovarian morphology (PCOM) in females between the ages of 21 and 45 who are in the reproductive stage and have isolated acne and/or androgenic alopecia. And their association. The present study was done with patients in the age group of 21 to 45 years with acne and/or androgenic alopecia. Modified Ferriman-Gallwey score was used to assess the degree of hirsutism (with score of more or equal to 8 as significant). Grading of acne vulgaris and androgenic alopecia was done by a single observer. Subjects were then evaluated for biochemical investigations of Hormonal assays on day 2 to 7. Transabdominal ultrasonography was performed in the follicular phase to demonstrate the ovarian morphology. In our study isolated androgenic alopecia was present in 28 patients (24.34%). In our study 54 (46.95%) patients out of 115 had combined acne and androgenic alopecia. In our study out of 33 patients with isolated acne 17 (51.5%) had PCO Morphology with grade I, grade II, grade III having prevalence of 46.2%, 53.8% and 57.1% respectively. In our study of the 28 patients with isolated androgenic alopecia 16 (57.1%) had PCOM with grade I, II and III respectively having prevalence of 56.3%, 55.6%, 66.7% with P value of 0.939. Patients with normal ovarian morphology were 12 in number (42.9%). Of the 54 patients with combined acne and androgenic alopecia 32 (59.3%) had PCOM and 22 patients had normal ovarian morphology. Higher overall prevalence was found in patients with combined acne and alopecia (59.3%) than in isolated groups; acne (51.5%), alopecia (57.1%). In our study it was to found that women with dermatological manifestations like acne and androgenic alopecia with regular menstruation. In our study it was found that these women with have high prevalence of PCOS.

AcneGrader: An ensemble pruning of the deep learning base models to grade acne.

BACKGROUND: Acne is one of the most common skin lesions in adolescents. Some severe or inflammatory acne leads to scars, which may have major impacts on patients' quality of life or even job prospects. Grading acne plays an important role in diagnosis, and the diagnosis is made by counting the number of acne. It is a labor-intensive job and it is easy for dermatologists to make mistakes, so it is very important to develop automatic diagnosis methods. Ensemble learning may improve the prediction results of the base models, but its time complexity is relatively high. The ensemble pruning strategy may solve this computational challenge by removing the redundant base models. MATERIALS AND METHODS: This study proposed a novel ensemble pruning framework of deep learning models to accurately detect and grade acne using images. First, we train multi-base models and prune the redundancy models according to the performance and diversity of the models. Then, we construct the new features of the training data by the base models we select in the previous step. Next, we remove the redundancy models further by a feature selection algorithm. Finally, we integrate all the base models by classifiers. The ensemble pruning algorithm was proposed to prune the deep learning base models. RESULTS: The experimental data showed that the ensemble pruned framework achieved a prediction accuracy of 85.82% on the acne dataset, better than the existing studies. To verify our method's effectiveness, we test our method in a skin cancer dataset and greatly outperform the state-of-the-art methods. CONCLUSION: The method we proposed is used to grade acne. Our method's performance outperforms state-of-the-art methods on two datasets, and it can also remove redundancy models to reduce computational complexity.

High-Frequency Ultrasonography Evaluation of Acne by Thickness and Power Doppler Vascular Analysis.

OBJECTIVES: To assess acne vulgaris quantitatively using high-frequency ultrasonography (HF-USG) and power Doppler (PD), and investigate the feasibility and application value of HF-USG and PD in acne vulgaris. METHODS: A total of 105 patients with the diagnosis of acne vulgaris in the face referred by a dermatologist were studied prospectively. All the acne patients enrolled were clinically classified by two attending dermatologists independently using three degrees with four levels of classification evaluating only the severest lesion. Gray-scale ultrasound was used to assess the thickness of the lesion, and the thickness ratio was calculated. PD equipped with Qpack semi-quantitative analysis software was used to assess blood signals of the lesion, and Qpack ratio, Qpack peak were calculated. Ten level-4 acne patients were re-evaluated after 2 weeks' treatment, and the results were compared with those before treatment. RESULTS: A total of 105 patients were categorized into four groups by dermatologists, 23 cases were comedones, 33 were papules, 26 were pustules, and 23 were nodules/cysts. There were significant differences in thickness ratio (P < .001), Qpack ratio (P < .001), and Qpack peak (P < .001) among the four groups. For the 10 level-4 acne patients treated 2 weeks by the dermatologist, the difference in thickness ratio between pre-treatment and post-treatment showed no significance (P = .06). However, Qpack ratio and Qpack peak were significantly decreased between pre-treatment and post-treatment (both P = .01). CONCLUSIONS: HF-USG and PD equipped with semi-quantitative analysis software can assess acne vulgaris quantitatively, which provides a good basis for the classification and treatment of acne. Their features include thickness ratio, Qpack ratio, and Qpack peak, with Qpack ratio and Qpack peak being the sensitive features for the early efficacy evaluation.

Subclinical effects of adapalene-benzoyl peroxide: a prospective in vivo imaging study on acne micromorphology and transfollicular delivery.

BACKGROUND: Adapalene-benzoyl peroxide (A-BPO) is a first-line topical treatment for acne vulgaris. In vivo reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) detect micromorphological changes over time and visualize transfollicular delivery. OBJECTIVES: To visualize temporal, subclinical effects of A-BPO on acne micromorphology using RCM and OCT, and evaluate their impact on transfollicular delivery of microparticulate carrier systems. METHODS: Fifteen patients with mild to moderate acne received a 6-week course of A-BPO. Micromorphological changes were evaluated at time 0, 3 and 6 weeks with RCM (n = 1190 images) and OCT (n = 210 scans). Transfollicular delivery of microparticles was assessed at baseline and week 6. RESULTS: In vivo imaging visualized steady normalization of skin micromorphology in response to A-BPO over 6 weeks, including decreased hyperkeratinization of follicular borders (RCM median decrease -71.2%, P < 0.05), reduced intrafollicular keratinous content (RCM median decrease -47.7%, P < 0.05) and increased epidermal thickness (OCT median increase of 25.25%, P < 0.05). Imaging visualized microparticles in the follicular unit. Despite a visible reduction in keratin and sebum, transfollicular microparticle delivery appeared unaffected. CONCLUSIONS: Reflectance confocal microscopy and OCT detect A-BPO-induced changes in micromorphology and visualize transfollicular microparticle delivery. Keratolysis and sebolysis did not have a measurable effect on transfollicular delivery of microparticles.

High bacterial colonization and lipase activity in microcomedones.

BACKGROUND: Although acne vulgaris has a multifactorial aetiology, comedogenesis and bacteria colonization of the pilosebaceous unit are known to play a major role in the onset of inflammatory acne lesions. However, many aspects remain poorly understood such as where and when is the early stage of the Propionibacterium acnes colonization in follicular unit? Our research aimed at providing a precise analysis of microcomedone's structure to better understand the interplay between Propionibacterium acnes and follicular units, and therefore, the role of its interplay in the formation of acne lesions. METHODS: Microcomedones were sampled using cyanoacrylate skin surface stripping (CSSS). Their morphology was investigated with multiphoton imaging and their ultrastructure with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Bacterial lipase activity in the microcomedones was quantified using a dedicated enzymatic test as well as a Fourier Transform Infra-Red (FTIR) analysis. The porphyrin produced by bacteria was analysed with HPTLC and fluorescence spectroscopy. RESULTS: The imaging analysis showed that microcomedones' structure resembles a pouch, whose interior is mostly composed of lipids with clusters of bacteria and whose outer shell is made up of corneocyte layers. The extensive bacteria colonization is clearly visible using TEM. Even after sampling, clear lipase activity was still seen in the microcomedone. A high correlation, r = .85, was observed between porphyrin content measured with HPTLC and with fluorescence spectroscopy. These observations show that microcomedones, which are generally barely visible clinically, already contain a bacterial colonization.

Segmentation methods for acne vulgaris images: Proposal of a new methodology applied to fluorescence images.

BACKGROUND: Acne vulgaris is one of the most common human pathologies worldwide. Its prevalence causes a high healthcare expenditure. Acne healthcare costs and effects on individuals' quality of life lead to the need of analysing current acne evaluation, treatment and monitoring methods. One of the most common ones is manual lesion counting by a dermatologist. However, this technique has several limitations, such as time spent. That is the reason why the development of new computer-assisted techniques is needed in order to automatically count the acne lesions. MATERIALS AND METHODS: Using the fluorescence images, a segmentation algorithm is implemented in MATLAB. RESULTS: A new counting tool has been obtained that provides a form of objective evaluation of acne vulgaris disease. The effectiveness of the application of the segmentation method is more than 90%, being valid for the follow-up and diagnosis of injuries. CONCLUSION: Automated counting of acne lesions has been proposed to solve current limitations of evaluation and monitoring methods for acne vulgaris. It is clear that the use of machine learning algorithms such as k-means enables clinicians to objectively and quickly evaluate the severity of acne.

Automated grading of acne vulgaris by deep learning with convolutional neural networks.

BACKGROUND: The visual assessment and severity grading of acne vulgaris by physicians can be subjective, resulting in inter- and intra-observer variability. OBJECTIVE: To develop and validate an algorithm for the automated calculation of the Investigator's Global Assessment (IGA) scale, to standardize acne severity and outcome measurements. MATERIALS AND METHODS: A total of 472 photographs (retrieved 01/01/2004-04/08/2017) in the frontal view from 416 acne patients were used for training and testing. Photographs were labeled according to the IGA scale in three groups of IGA clear/almost clear (0-1), IGA mild (2), and IGA moderate to severe (3-4). The classification model used a convolutional neural network, and models were separately trained on three image sizes. The photographs were then subjected to analysis by the algorithm, and the generated automated IGA scores were compared to clinical scoring. The prediction accuracy of each IGA grade label and the agreement (Pearson correlation) of the two scores were computed. RESULTS: The best classification accuracy was 67%. Pearson correlation between machine-predicted score and human labels (clinical scoring and researcher scoring) for each model and various image input sizes was 0.77. Correlation of predictions with clinical scores was highest when using Inception v4 on the largest image size of 1200 × 1600. Two sets of human labels showed a high correlation of 0.77, verifying the repeatability of the ground truth labels. Confusion matrices show that the models performed sub-optimally on the IGA 2 label. CONCLUSION: Deep learning techniques harnessing high-resolution images and large datasets will continue to improve, demonstrating growing potential for automated clinical image analysis and grading.

3D surface texture analysis of high-resolution normal fields for facial skin condition assessment.

BACKGROUND: This paper investigates the use of a light stage to capture high-resolution, 3D facial surface textures and proposes novel methods to use the data for skin condition assessment. MATERIALS AND METHODS: We introduce new methods for analysing 3D surface texture using high-resolution normal fields and apply these to the detection and assessment of skin conditions in human faces, specifically wrinkles, pores and acne. The use of high-resolution normal maps as input to our texture measures enables us to investigate the 3D nature of texture, while retaining aspects of some well-known 2D texture measures. The main contributions are as follows: the introduction of three novel methods for extracting texture descriptors from high-resolution surface orientation fields; a comparative study of 2D and 3D skin texture analysis techniques; and an extensive data set of high-resolution 3D facial scans presenting various skin conditions, with human ratings as "ground truth." RESULTS: Our results demonstrate an improvement on state-of-the-art methods for the analysis of pores and comparable results to the state of the art for wrinkles and acne using a considerably more compact model. CONCLUSIONS: The use of high-resolution normal maps, captured by a light stage, and the methods described, represent an important new set of tools in the analysis of skin texture.

Quantitative evaluation of atrophic acne scars using 3D image analysis with reflected LED light.

BACKGROUND: Methods for objective evaluation of acne scars have not been established yet. In this study, the capability of three-dimensional image analysis of acne scarring was examined. METHODS: Two dermatologists evaluated the severity and counted the number of atrophic acne scars in a defined evaluation area of each cheek (3.5 cm × 3.5 cm) of 22 subjects (age, 21-38 years). Images of the evaluation area were obtained with an Antera 3D® (Miravex Limited, Ireland) camera three times, and three parameters (affected area, volume, and max depth) were measured. Three different filters (small, medium, and large), which limit measurement targets based on the diameters of concavities, were used for measurement. The relationships between each parameter and the evaluation results of scars by dermatologists were analyzed using Spearman's correlation coefficients. RESULTS: The correlations between the evaluation results of scars by dermatologists and each parameter measured were the highest when the large filter was used. The correlation coefficients between the severity of scars by dermatologists and each of affected area, volume, and max depth were 0.736, 0.728, and 0.722, respectively, and those between scar counts and each of affected area and volume were 0.783 and 0.770, respectively. The correlations, scatter plots, and regression lines among three measurements of parameters suggested high repeatability. CONCLUSIONS: Three-dimensional image analysis has the capability to evaluate changes in the shape of scars before and after treatment quantitatively.

First Use of Optical Coherence Tomography on In Vivo Inflammatory Acne-Like Lesions: A Murine Model.

BACKGROUND AND OBJECTIVES: Successful outcomes of clinical studies for acne vulgaris depend greatly on achieving statistically significant reduction in acne lesion count and improvement in Investigator's Global Assessment score of the investigational drug product against its vehicle control. To date, there has not been a validated preclinical acne model to evaluate investigational drug products in order to improve the probability of clinical success. An inflammatory acne-like lesion mouse model developed in-house has previously been used for clinical guidance in our drug development program. In this study, we aim to implement and assess the adequacy of swept-source optical coherence tomography (SS-OCT) in quantifying the dynamic changes in inflammatory acne-like lesions. STUDY DESIGN/MATERIALS AND METHODS: Live Propionibacterium acnes bacteria were injected intradermally resulting in inflammatory acne-like lesions. Topical 1% and 2% minocycline gels were applied to the lesions in separate groups once daily for 2 weeks and compared with vehicle and untreated control groups. The growth of these lesions was monitored and measured with a ruler (height)/microcaliper (width)-an approach previously developed, and with SS-OCT. The reliability of the two methods were assessed. Acquired OCT images across the apex of these inflammatory lesions were statistically analyzed for lesion volume reduction from baseline as well as between the treatment groups and the control groups. RESULTS: The OCT technique allowed for reliable lesion volume analysis with varying conic profiles. After 14 days of topical minocycline treatments (1%, 2% minocycline), statistically significant reduction in lesion volume (P ≤ 0.05) based on OCT image analysis was observed compared with untreated and vehicle control groups as well as compared with baseline measurements. Under the right conditions, some morphological aspects of the P. acnes injection site were discernible within the skin in images captured with OCT. CONCLUSIONS: We demonstrated the first use of SS-OCT in evaluating in vivo inflammatory acne-like lesions in a murine model. Our findings support the use of OCT in assessing lesion size and evolution of P. acnes injection sites non-invasively in preclinical in vivo studies, which could potentially lead to more consistent and predictable outcomes in clinical development. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

In Vivo Reflectance Confocal Microscopy of Gold Microparticles Deposited in the Skin. A Case Report on Cutaneous Chrysiasis.

Cutaneous chrysiasis is gold deposition in the dermis, described after parenteral administration of gold salts or after topical exposure to gold-containing materials. Gold microparticles (GMPs) have versatile therapeutic effects and are increasingly used in medicine. This case report describes the development of a blue-gray macule following the facial application of GMPs and laser treatment of acne vulgaris. Dermoscopy showed a nonspecific homogenous blue-gray pattern, gradually fading over an 8-month-period. Reflectance confocal microscopy (RCM) detected hyperreflective, subcellular particles in the papillary dermis, localized around hair follicles, eccrine glands, and inside macrophages. Histopathological evaluation, darkfield illumination with hyperspectral imaging, and neutron activation analysis confirmed the presence of GMPs in the dermis. RCM allowed non-invasive fast visualization of aggregates of hyperreflective particles in the dermis and can potentially be used for monitoring localized cutaneous chrysiasis and other metal deposition conditions over time. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Assessment of macular choroidal thickness, central macular thickness and retinal nerve fiber layer in patients receiving oral isotretinoin treatment.

PURPOSE: To investigate the impact of oral isotretinoin therapy in choroidal thickness, central macular thickness (CMT), and retinal nerve fibre layer (RNFL) thickness using optical coherence tomography (OCT). PATIENTS AND METHODS: Choroidal thicknesses, CMT, and RNFL thickness of 64 eyes were evaluated at baseline and the end of the third month of isotretinoin therapy by spectral-domain OCT. For assessment of choroidal thickness, OCT measurements were obtained at the fovea with 6 additional measurements at adjacent locations (at 500-1000-1500 µm temporal to the fovea and 500-1000-1500 µm nasal to the fovea). RESULTS: There was not a statistically significant difference between the baseline and third-month follow-up measurements of choroidal thicknesses at seven distinct locations (p > 0.05). Similarly, RNFL thickness and CMT did not change with a mean dose of 30 (±6) mg per day isotretinoin therapy during follow-up (101.82 vs 102.24, p = 0.079; 217.77 vs 217.25, p = 0.731, respectively). CONCLUSION: After the use of oral isotretinoin for 3 months, no significant side effects have been observed in choroidal thickness, CMT, and RNFL thickness by OCT.

Multimodal Clinical Imaging Assessment of the Outcome in Mild-to-Moderate Acne: A Prospective Study.

BACKGROUND: The quality of outcome assessment in acne studies has been either subjective/insufficient or time consuming through the ordinary lesion counting. OBJECTIVE: To evaluate the application of multimodal clinical imaging (MCI), a combination of imaging technology and computation, in the assessment of acne lesions in a clinical study setting. METHODS: A prospective, monocentric, single-group open study designed to evaluate the efficacy and tolerance of a cosmetic product (IP/SG) in subjects with mild-to-moderate facial acne by classical clinical counting (CCC) - change in the total/inflammatory/noninflammatory acne lesion number compared with baseline (D0) - Investigator Global Assessment (IGA) and self-reported outcomes. Concomitantly, MCI was administered. The study was performed for 12 weeks (D84) with a 4-week follow-up (D112). RESULTS: Mean age of patients (n = 49) was 18.2 ± 3.7 years (range 13-25). The mean acne duration was 3.8 ± 2.8 years. The total number of lesions did not differ significantly between D0/D84 by both CCC and MCI. However, the Cardiff Acne Disability Index (CADI) and uncomfortable feeling improved at D28/D0, the perception of oily skin improved at D14/D0, and the perception of sticky skin improved from D28/D0 to D56/D0. Deterioration was detected between D84/D0 and D112/D0, namely after product discontinuation. Interestingly, a change in trend was recorded for acne lesions at D14/D0 by MCI but not by CCC. CONCLUSION: MCI, applied for the first time in a small clinical study setting, is at least as reliable as CCC and may allow for a sensitive longitudinal evaluation of single acne lesions and their response to products, especially in conditions where clinical evaluation reaches its limits.

Three-dimensional reconstruction of skin disease using multi-view mobile images.

BACKGROUND/PURPOSE: In skin beauty area, interest in diagnosis and management methods for acne is increasing. However, it is difficult to diagnose protruding skin disease by two-dimensional (2D) image. Three-dimensional (3D) approach is needed. The purpose of this study was to propose a system for reconstructing 3D model (visual hull) of 2D images obtained using mobile devices. METHODS: Acne images were acquired using a 3D printing mobile image acquisition system. Using two attached mirrors, five multi-view acne silhouette images were obtained. They were then, reconstructed to 3D. To measure the volume of the formed 3D model (visual hull), post-processing, calculation, and texture mapping were performed. The volume of acne samples designed with 3D printing was compared with the volume calculated in the produced system using statistical analysis program. RESULTS: The 3D modeling program demonstrated its superiority by showing high correlation (r = 0.783) between the actual volume of acne and the volume calculated by the system. The 3D model (visual hull) was successfully reconstructed by capturing 2D images of actual acne. CONCLUSION: In this study, we created a system to reconstruct small sized protruding skin disease images such as acne obtained with mobile devices. The 3D printing system was used to obtain images from mobile camera and reconstructed to 3D. To verify the volume of the reconstructed model, 3D printing samples were produced and compared with the calculated actual volume. It can be used, for initial diagnosis by receiving information about the protruding skin disease without space-time constraints using a mobile device.

Use of Raman spectroscopy in the assessment of skin after CO2 ablative fractional laser surgery on acne scars.

BACKGROUND: Ablative fractional laser surgery is a common technique for treating acne scars. However, an in vivo and noninvasive analysis of the histologic variations between acne skin and the resulting resurfaced skin is needed in order to evaluate the wound healing process of the scars induced by the ablative fractional laser surgery. MATERIALS AND METHODS: Nine patients with acne scars underwent a single treatment with a CO2 ablative fractional laser surgery. Collagen presence on the resurfaced skin was noninvasively assessed by means of Raman spectroscopy and principal component analysis. RESULTS: Principal component analysis shows that all the patients presented a collagen regeneration on the resurfaced skin after the laser treatment. CONCLUSION: Collagen plays a crucial role in the wound healing process. By assessing the collagen presence on the skin, it was possible to quantify the regenerative effects of the ablative fractional laser in a noninvasive way.

Acne vulgaris severity graded by in vivo reflectance confocal microscopy and optical coherence tomography.

INTRODUCTION: Acne is an inflammatory disease of the pilosebaceous unit, which can be investigated in vivo using reflectance confocal microscopy (RCM) and optical coherence tomography (OCT). OBJECTIVES: By means of RCM and OCT to identify morphological characteristics of acne that may be associated with clinical acne severity. METHODS: Patients with mild to moderate facial acne (n = 14, Investigators Global Assessment scale, IGA 1-3), and healthy participants (n = 7, IGA 0) were included in this explorative study. A total of 108 RCM image blocks and 54 OCT scans (each RCM and OCT image measuring 6 × 6 mm) were captured from lesional-, perilesional, and lesion-free skin areas. Acne lesions, infundibular regions of follicles and inflammation degree were compared in acne patients and healthy participants. RESULTS: Combined use of RCM and OCT demonstrated infundibular morphology, acne lesions, and blood flow. RCM images of perilesional- and lesion-free skin in acne patients revealed follicle infundibula with hyperkeratinized borders and abundant keratin plugs, contrasting skin of healthy participants. Higher acne severity related to increased number of follicles with hyperkeratotic borders (P = 0.04) and keratin plugs (P = 0.006), increased infundibulum diameter (P < 0.001), increased density of inflammatory cells (P < 0.001), and blood flow (P = 0.03). Acne lesion morphology was not associated with acne severity. CONCLUSION: Combined use of RCM and OCT elucidated distinctive follicle infundibulum characteristics and inflammation degree that were associated with acne severity. Future trials may apply imaging techniques to support clinical acne grading, and monitor treatment efficacy. Lasers Surg. Med. 51:104-113, 2019. © 2018 Wiley Periodicals, Inc.

Prospective Evaluation of Atrophic Acne Scars on the Face With Needle-Free High-Pressure Pneumatic Injection: Quantitative Volumetric Scar Improvement.

BACKGROUND: Atrophic acne facial scars still pose a treatment challenge. Needle-free high-pressure pneumatic injection has recently been introduced; however, few studies exist regarding its effectiveness. OBJECTIVE: To evaluate the efficacy and safety of pneumatic injection for treating atrophic acne scars using a 3-dimensional optical profiling system. METHODS AND MATERIALS: A pneumatic injection device with a 0.2-mm nozzle diameter, 50% pressure power, and 85-µL injection volume was used. The degree of depression was examined and analyzed using a 3-dimensional optical profiling system and clinical photographs. The patients also evaluated any side effects. Each subject underwent a single treatment session and was followed up after 1 and 2 months. RESULTS: A total of 13 atrophic acne scars from 10 Korean men and women aged 20 to 29 (mean age 25.8 ± 2.4) years were studied. The mean scar volume values were 0.964, 0.741, and 0.566 mm, respectively, at baseline, 1 month, and 2 months after the injection. Scar volumes after 2 months were significantly different compared with baseline volumes. However, there was no significant difference between the baseline and 1-month volumes. CONCLUSION: Treatment with pneumatic injection is safe and effective in reducing atrophic acne facial scars; it results in quantitative improvement in scar volumes.

The evolution of healthy skin to acne lesions: a longitudinal, in vivo evaluation with reflectance confocal microscopy and optical coherence tomography.

BACKGROUND: Comedogenesis is defined as the process of the development of a new comedo, which is of great importance for the understanding of acne. OBJECTIVE: To evaluate the formation and evolution of acne lesions from clinically unaffected skin of patients with mild-moderate acne to characterize the morphological changes and natural resolution by means of in vivo reflectance confocal microscopy (RCM) and dynamic optical coherence tomography (D-OCT). METHODS: Ten patients with mild-moderate acne, not assuming any topical or systemic therapy, comprised between 12 and 30 years of age, were recruited. A target area of 4 × 4 mm of the face, without acne lesions at baseline, was selected. A set of standardized clinical pictures, RCM and D-OCT images were acquired weekly for 6 weeks and evaluated. RESULTS: Seventy full sets of clinical, RCM and D-OCT images were analysed. The appearance of acne lesion is preceded by an increase of large bright follicles in the area corresponding to infundibular keratinization, followed by increment of inflammation parameter, such as increased of small bright cells upon RCM and vascular network upon D-OCT, which return to normal after the resolution of acute inflammation. CONCLUSION: Acne skin dynamics is complex and seems characterized by the early increase in the number of dysmorphic pilosebaceous units and the hyperkeratinization of the acroinfundibulum of the pilosebaceous duct prior to the occurrence of inflammatory events around the follicle. The processes of hyperkeratinization and inflammatory phenomena may generate a pathologic vicious cycle, which characterizes acne through progressive worsening and a self-sustainment mechanism.

Evolution and duration of nodules in severe nodular acne on the back: results from a four-week non-interventional, prospective study.

BACKGROUND: Severe nodular acne is characterized by inflammatory nodules and scarring. Their natural evolution and duration are insufficiently investigated. AIM: To investigate the evolution and duration of untreated acne nodules. METHODOLOGY: Four-week, single-centre, non-interventional, prospective study in subjects with severe nodular acne on the back. Nodule evolution and duration was assessed using standardized photographs taken twice weekly. RESULTS: Data from 23 subjects were evaluable. Mean age was 25.1 ± 4.9 years, 87% were males, and mean acne duration was 9.7 ± 6.7 years. At baseline, the overall total nodule count was 132 (mean number: 5.7 ± 3.0 nodules/subject). Among others, the following two main pathways were observed: nodules evolving directly into atrophic scars (31.8%) and nodules evolving towards papules into atrophic scars (37.9%). After 4 weeks, 77.3% of baseline nodules had evolved into atrophic scars. After baseline visit, a total of 247 new nodules (3.1 ± 2.2 nodules/week/subject) with a mean duration of 4.9 ± 2.6 days were observed. The mean duration of new nodules was significantly longer in subjects (n = 16) with ≥6 new nodules compared to subjects (n = 7) with <6 new nodules (5.2 ± 1.4 vs. 3.6 ± 0.8 days; P = 0.008)). There was no correlation between the number of new nodules and acne duration or with the number of baseline nodules. CONCLUSION: This study documents the natural nodule evolution and duration over 4 weeks and showed in 23 patients the scarring potential of untreated severe nodular acne of the back.