This study was registered at the German Clinical Trial Register (DRKS-Study-ID: DRKS00013570; https://www.drks.de/drks_web/).

Mailings and social media posts of the International Dermoscopy Society were used to recruit targeted groups. The recruitment was focused on medical personell interested in the diagnosis of skin cancer. It is possible that recruitment of raters is influenced by self-selection bias and therefore biased towards the selection of motivated and skilled raters. Skill level was included as a covariate in the interaction experiments. Each rater had to perform multiple screening tests to ensure that the self-reported experience matched actual skills. Because of self selection bias, the generalisability of our results to a less motivated group of readers may be limited. Ethics oversightEthics review board of the Medical University of Vienna Note that full information on the approval of the study protocol must also be provided in the manuscript.

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SummaryBackgroundEven though progress has been made, the detection of melanoma still poses a challenge. In light of this situation, the Nevisense electrical impedance spectroscopy (EIS) system (SciBase AB, Stockholm, Sweden) was designed and shown to have the potential to be used as an adjunct diagnostic tool for melanoma detection.ObjectivesTo assess the effectiveness and safety of the Nevisense system in the distinction of benign lesions of the skin from melanoma with electrical impedance spectroscopy.MethodsThis multicentre, prospective, and blinded clinical study was conducted at five American and 17 European investigational sites. All eligible skin lesions in the study were examined with the EIS-based Nevisense system, photographed, removed by excisional biopsy and subjected to histopathological evaluation. A postprocedure clinical follow-up was conducted at 7 ± 3 days from the initial measurement. A total of 1951 patients with 2416 lesions were enrolled into the study; 1943 lesions were eligible and evaluable for the primary efficacy end point, including 265 melanomas – 112 in situ and 153 invasive melanomas with a median Breslow thickness of 0·57 mm [48 basal cell carcinomas (BCCs) and seven squamous cell carcinomas (SCCs)].ResultsThe observed sensitivity of Nevisense was 96·6% (256 of 265 melanomas) with an exact one-sided 95% lower confidence bound estimated at 94·2% and an observed specificity of 34·4%, and an exact two-sided 95% confidence bound estimated at 32·0–36·9%. The positive and negative predictive values of Nevisense were 21·1% and 98·2%, respectively. The observed sensitivity for nonmelanoma skin cancer was 100% (55 of 48 BCCs and seven SCCs) with an exact two-sided 95% confidence bound estimated at 93·5–100·0%.ConclusionsNevisense is an accurate and safe device to support clinicians in the detection of cutaneous melanoma.What's already known about this topic?Although progress has been made in the detection of melanoma it still poses a challenge.Electrical impedance spectroscopy (EIS) may potentially be used as a diagnostic aid for the detection of melanoma.What does this study add? In the largest international prospective study of its kind in melanoma detection, the EIS system Nevisense was shown to be both accurate and safe in the lesion cohort studied. In the absence of a perfect gold standard, the accuracy of a device should be compared with the consensus diagnosis from multiple experts.

Summary Background Over the last few years, several articles on dermoscopy of non‐neoplastic dermatoses have been published, yet there is poor consistency in the terminology among different studies. Objectives We aimed to standardize the dermoscopic terminology and identify basic parameters to evaluate in non‐neoplastic dermatoses through an expert consensus. Methods The modified Delphi method was followed, with two phases: (i) identification of a list of possible items based on a systematic literature review and (ii) selection of parameters by a panel of experts through a three‐step iterative procedure (blinded e‐mail interaction in rounds 1 and 3 and a face‐to‐face meeting in round 2). Initial panellists were recruited via e‐mail from all over the world based on their expertise on dermoscopy of non‐neoplastic dermatoses. Results Twenty‐four international experts took part in all rounds of the consensus and 13 further international participants were also involved in round 2. Five standardized basic parameters were identified: (i) vessels (including morphology and distribution); (ii) scales (including colour and distribution); (iii) follicular findings; (iv) ‘other structures’ (including colour and morphology); and (v) ‘specific clues’. For each of them, possible variables were selected, with a total of 31 different subitems reaching agreement at the end of the consensus (all of the 29 proposed initially plus two more added in the course of the consensus procedure). Conclusions This expert consensus provides a set of standardized basic dermoscopic parameters to follow when evaluating inflammatory, infiltrative and infectious dermatoses. This tool, if adopted by clinicians and researchers in this field, is likely to enhance the reproducibility and comparability of existing and future research findings and uniformly expand the universal knowledge on dermoscopy in general dermatology. What's already known about this topic? Over the last few years, several papers have been published attempting to describe the dermoscopic features of non‐neoplastic dermatoses, yet there is poor consistency in the terminology among different studies. What does this study add? The present expert consensus provides a set of standardized basic dermoscopic parameters to follow when evaluating inflammatory, infiltrative and infectious dermatoses. This consensus should enhance the reproducibility and comparability of existing and future research findings and uniformly expand the universal knowledge on dermoscopy in general dermatology.

In this open, controlled, multicentre and prospective observational study, smartphone teledermoscopy referrals were sent from 20 primary healthcare centres to 2 dermatology departments for triage of skin lesions of concern using a smartphone application and a compatible digital dermoscope. The outcome for 816 patients referred via smartphone teledermoscopy was compared with 746 patients referred via the traditional paper-based system. When surgical treatment was required, the waiting time was significantly shorter using teledermoscopy for patients with melanoma, melanoma in situ, squamous cell carcinoma, squamous cell carcinoma in situ and basal cell carcinoma. Triage decisions were also more reliable with teledermoscopy and over 40% of the teledermoscopy patients could potentially have avoided face-to-face visits. Only 4 teledermoscopy referrals (0.4%) had to be excluded due to poor image quality. Smartphone teledermoscopy referrals allow for faster and more efficient management of patients with skin cancer as compared to traditional paper referrals.

IMPORTANCE Convolutional neural networks (CNNs) achieve expert-level accuracy in the diagnosis of pigmented melanocytic lesions. However, the most common types of skin cancer are nonpigmented and nonmelanocytic, and are more difficult to diagnose. OBJECTIVE To compare the accuracy of a CNN-based classifier with that of physicians with different levels of experience. DESIGN, SETTING, AND PARTICIPANTS A CNN-based classification model was trained on 7895 dermoscopic and 5829 close-up images of lesions excised at a primary skin cancer clinic between January 1, 2008, and July 13, 2017, for a combined evaluation of both imaging methods. The combined CNN (cCNN) was tested on a set of 2072 unknown cases and compared with results from 95 human raters who were medical personnel, including 62 board-certified dermatologists, with different experience in dermoscopy. MAIN OUTCOMES AND MEASURES The proportions of correct specific diagnoses and the accuracy to differentiate between benign and malignant lesions measured as an area under the receiver operating characteristic curve served as main outcome measures. RESULTS Among 95 human raters (51.6% female; mean age, 43.4 years; 95% CI, 41.0-45.7 years), the participants were divided into 3 groups (according to years of experience with dermoscopy): beginner raters (<3 years), intermediate raters (3-10 years), or expert raters (>10 years). The area under the receiver operating characteristic curve of the trained cCNN was higher than human ratings (0.742; 95% CI, 0.729-0.755 vs 0.695; 95% CI, 0.676-0.713; P < .001). The specificity was fixed at the mean level of human raters (51.3%), and therefore the sensitivity of the cCNN (80.5%; 95% CI, 79.0%-82.1%) was higher than that of human raters (77.6%; 95% CI, 74.7%-80.5%). The cCNN achieved a higher percentage of correct specific diagnoses compared with human raters (37.6%; 95% CI, 36.6%-38.4% vs 33.5%; 95% CI, 31.5%-35.6%; P = .001) but not compared with experts (37.3%; 95% CI, 35.7%-38.8% vs 40.0%; 95% CI, 37.0%-43.0%; P = .18). CONCLUSIONS AND RELEVANCE Neural networks are able to classify dermoscopic and close-up images of nonpigmented lesions as accurately as human experts in an experimental setting.

The onset of FD before 25 years of age and the presence of pustules within the alopecic patch were associated with severe FD. Tetracyclines and the combination of clindamycin and rifampicin were the most useful treatments.