H. Peter Soyer

Nanoparticles and microparticles for skin drug delivery

Skin is a widely used route of delivery for local and systemic drugs and is potentially a route for their delivery as nanoparticles. The skin provides a natural physical barrier against particle penetration, but there are opportunities to deliver therapeutic nanoparticles, especially in diseased skin and to the openings of hair follicles. Whilst nanoparticle drug delivery has been touted as an enabling technology, its potential in treating local skin and systemic diseases has yet to be realised. Most drug delivery particle technologies are based on lipid carriers, i.e. solid lipid nanoparticles and nanoemulsions of around 300 nm in diameter, which are now considered microparticles. Metal nanoparticles are now recognized for seemingly small drug-like characteristics, i.e. antimicrobial activity and skin cancer prevention. We present our unpublished clinical data on nanoparticle penetration and previously published reports that support the hypothesis that nanoparticles >10nm in diameter are unlikely to penetrate through the stratum corneum into viable human skin but will accumulate in the hair follicle openings, especially after massage. However, significant uptake does occur after damage and in certain diseased skin. Current chemistry limits both atom by atom construction of complex particulates and delineating their molecular interactions within biological systems. In this review we discuss the skin as a nanoparticle barrier, recent work in the field of nanoparticle drug delivery to the skin, and future directions currently being explored.

Dermoscopic Evaluation of Amelanotic and Hypomelanotic Melanoma

OBJECTIVE To determine the predictive dermoscopic features of amelanotic and hypomelanotic melanoma. DESIGN A total of 105 melanomas (median Breslow thickness, 0.76 mm), 170 benign melanocytic lesions, and 222 nonmelanocytic lesions lacking significant pigment (amelanotic, partially pigmented, and light colored) were imaged using glass-plate dermoscopy devices and scored for 99 dermoscopic features. Diagnostic models were derived from and tested on independent randomly selected lesions. SETTING Predominantly hospital-based clinics from 5 continents. MAIN OUTCOME MEASURES Sensitivity, specificity, and odds ratios for individual features and models for the diagnosis of melanoma and malignancy. RESULTS The most significant negative predictors of melanoma were having multiple (>3) milialike cysts (odds ratio, 0.09; 95% confidence interval, 0.01-0.64), comma vessels with a regular distribution (0.10; 0.01-0.70), comma vessels as the predominant vessel type (0.16; 0.05-0.52), symmetrical pigmentation pattern (0.18; 0.09-0.39), irregular blue-gray globules (0.20; 0.05-0.87), and multiple blue-gray globules (0.28; 0.10-0.81). The most significant positive predictors were having a blue-white veil (odds ratio,13; 95% confidence interval, 3.9-40.0), scarlike depigmentation (4.4; 2.4-8.0), multiple blue-gray dots (3.5; 1.9-6.4), irregularly shaped depigmentation (3.3; 2.0-5.3), irregular brown dots/globules (3.2; 1.8-5.6), 5 to 6 colors (3.2; 1.6-6.3), and predominant central vessels (3.1; 1.6-6.0). A simple model distinguishing melanomas from all nonmelanomas had a sensitivity of 70% and a specificity of 56% in the test set. A model distinguishing all malignant lesions from benign lesions had a sensitivity of 96% and a specificity of 37%. Conclusion Although the diagnostic accuracy of dermoscopy for melanoma lacking significant pigment is inferior to that of more pigmented lesions, features distinguishing the former from benign lesions can be visualized on dermoscopic evaluation.

Dermoscopy in general dermatology

Dermoscopy improves the diagnostic accuracy in the clinical evaluation of pigmented skin lesions, but it is also useful for the assessment of vascular structures that are not visible to the naked eye. As a consequence, dermoscopy has been employed more and more for the differential diagnosis of nonpigmented skin disorders, including tumors but also inflammatory and infectious diseases. This article provides a review of the dermoscopic features seen in various nonpigmented tumoral and nontumoral skin lesions as well as the dermoscopic criteria used for monitoring skin reactions to various treatments.

Dermoscopy Improves Accuracy of Primary Care Physicians to Triage Lesions Suggestive of Skin Cancer

PURPOSE Primary care physicians (PCPs) constitute an appropriate target for new interventions and educational campaigns designed to increase skin cancer screening and prevention. The aim of this randomized study was to determine whether the adjunct of dermoscopy to the standard clinical examination improves the accuracy of PCPs to triage lesions suggestive of skin cancer. PATIENTS AND METHODS PCPs in Barcelona, Spain, and Naples, Italy, were given a 1-day training course in skin cancer detection and dermoscopic evaluation, and were randomly assigned to the dermoscopy evaluation arm or naked-eye evaluation arm. During a 16-month period, 73 physicians evaluated 2,522 patients with skin lesions who attended their clinics and scored individual lesions as benign or suggestive of skin cancer. All patients were re-evaluated by expert dermatologists at clinics for pigmented lesions. Referral accuracy of both PCP groups was calculated by their scores, which were compared to those tabulated for dermatologists. RESULTS Referral sensitivity, specificity, and positive and negative predictive values were 54.1%, 71.3%, 11.3%, and 95.8%, respectively, in the naked-eye arm, and 79.2%, 71.8%, 16.1%, and 98.1%, respectively, in the dermoscopy arm. Significant differences were found in terms of sensitivity and negative predictive value (P = .002 and P = .004, respectively). Histopathologic examination of equivocal lesions revealed 23 malignant skin tumors missed by PCPs performing naked-eye observation and only six by PCPs using dermoscopy (P = .002). CONCLUSION The use of dermoscopy improves the ability of PCPs to triage lesions suggestive of skin cancer without increasing the number of unnecessary expert consultations.

Three-point checklist of dermoscopy

Background: Dermoscopy used by experts has been demonstrated to improve the diagnostic accuracy for melanoma. However, little is known about the diagnostic validity of dermoscopy when used by nonexperts. Objective: To evaluate the diagnostic performance of nonexperts using a new 3-point checklist based on a simplified dermoscopic pattern analysis. Methods: Clinical and dermoscopic images of 231 clinically equivocal and histopathologically proven pigmented skin lesions were examined by 6 nonexperts and 1 expert in dermoscopy. For each lesion the nonexperts assessed 3 dermoscopic criteria (asymmetry, atypical network and blue-white structures) constituting the 3-point method. In addition, all examiners made an overall diagnosis by using standard pattern analysis of dermoscopy. Results: Asymmetry, atypical network and blue-white structures were shown to be reproducible dermoscopic criteria, with a kappa value ranging from 0.52 to 0.55. When making the overall diagnosis, the expert had 89.6% sensitivity for malignant lesions (tested on 68 melanomas and 9 pigmented basal cell carcinomas), compared to 69.7% sensitivity achieved by the nonexperts. Remarkably, the sensitivity of the nonexperts using the 3-point checklist reached 96.3%. The specificity of the expert using overall diagnosis was 94.2% compared to 82.8 and 32.8% achieved by the nonexperts using overall diagnosis and 3-point checklist, respectively. Conclusion: The 3-point checklist is a valid and reproducible dermoscopic algorithm with high sensitivity for the diagnosis of melanoma in the hands of non-experts. Thus it may be applied as a screening procedure for the early detection of melanoma.

Teledermoscopy - results of a multicentre study on 43 pigmented skin lesions

We performed a multicentre study to evaluate the agreement between the direct clinical diagnosis and the telediagnosis of 43 cutaneous pigmented lesions. Digital clinical and dermoscopic images of the 43 pigmented skin lesions (11 melanomas, 23 melanocytic naevi, three basal cell carcinomas, three lentigines, two seborrhoeic keratoses and one angiokeratoma) were sent by email to 11 colleagues (six dermatologists, two residents in dermatology, one oncologist, one specialist in internal medicine and one general practitioner) in 10 centres. These 11 colleagues had different degrees of experience in dermoscopy. With histopathology as the gold standard, an average of 85% of the telediagnoses were correct, with results varying from 77% to 95%, whereas face-to-face diagnosis by an expert dermatologist was correct in 91% of cases. The kappa value for all participants ranged from 0.35 to 0.87. The results confirm that teledermoscopy can be a reliable technique for the diagnosis of pigmented skin lesions but one that will depend on the expertise of the observer.

Melanoma screening with cellular phones.

Background Mobile teledermatology has recently been shown to be suitable for teledermatology despite limitations in image definition in preliminary studies. The unique aspect of mobile teledermatology is that this system represents a filtering or triage system, allowing a sensitive approach for the management of patients with emergent skin diseases. Methodology/Principal Findings In this study we investigated the feasibility of teleconsultation using a new generation of cellular phones in pigmented skin lesions. 18 patients were selected consecutively in the Pigmented Skin Lesions Clinic of the Department of Dermatology, Medical University of Graz, Graz (Austria). Clinical and dermoscopic images were acquired using a Sony Ericsson with a built-in two-megapixel camera. Two teleconsultants reviewed the images on a specific web application (http://www.dermahandy.net/default.asp) where images had been uploaded in JPEG format. Compared to the face-to-face diagnoses, the two teleconsultants obtained a score of correct telediagnoses of 89% and of 91.5% reporting the clinical and dermoscopic images, respectively. Conclusions/Significance The present work is the first study performing mobile teledermoscopy using cellular phones. Mobile teledermatology has the potential to become an easy applicable tool for everyone and a new approach for enhanced self-monitoring for skin cancer screening in the spirit of the eHealth program of the European Commission Information for Society and Media.

Adverse reactions after cosmetic lip augmentation with permanent biologically inert implant materials

Augmentation of lips is a common aesthetic procedure that is mostly performed with alloplastic materials or autologous tissue. Various alloplastic injectable implants have been developed for soft tissue augmentation without surgery. Most biologic materials are resorbed within a few months, fluid silicone may migrate, and autologous fat is not ideal for fine contouring of the lips. The search for a biocompatible, permanent, nontoxic, and biologically inert filler material led to the development of some new materials for subdermal or intradermal implantation. Recently Bioplastique, Artecoll, and Gore-Tex have been well established and recommended by many authors. Although these materials meet most of the characteristics that constitute an ideal injectable prosthetic material, we describe 3 examples of adverse reactions after their implantation into lips.

Mobile teledermatology: A feasibility study of 58 subjects using mobile phones

Summary We investigated the diagnostic agreement between teledermatology based on images from a mobile phone camera and face-to-face (FTF) dermatology. Diagnostic agreement was assessed for two teledermatologists (TD) in comparison with FTF consultations in 58 subjects. In almost three-quarters of the cases (TD1: 71%; TD2: 76%), the telediagnosis was fully concordant with the FTF diagnosis. Furthermore, the diagnosed diseases were almost all in the same diagnostic category (TD1: 97%; TD2: 90%). If mobile teledermatology had been used for remote triage, TD1 could have treated 53% subjects remotely and 47% subjects would have had to consult a dermatologist FTF. TD2 could have treated 59% subjects remotely, whereas 41% subjects would have had to consult a dermatologist FTF. Forty-eight subjects responded to a questionnaire, of whom only 10 had any concerns regarding teledermatology. Thirty-one subjects stated that they would be willing to pay to use a similar service in future and suggested an amount ranging from €5 to €50 per consultation (mean €22) (€ = £0.7, US

Applications of multiphoton tomographs and femtosecond laser nanoprocessing microscopes in drug delivery research

1.4). These results are encouraging as patient acceptance and reimbursement represent potential obstacles to the implementation of telemedicine services.