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.

Skin cancer, including melanoma and non-melanoma skin cancer (NMSC), represents the most common type of malignancy in the white population. The incidence rate of melanoma is increasing worldwide, while the associated mortality remains stable, or is slightly decreasing. On the other hand, the incidence for NMSC varies widely, with the highest rates reported in Australia.In the current review, we highlight recent global trends in epidemiology of skin cancer. We discuss controversial issues raised in current epidemiological data, we analyze the most important risk factors associated with the development of melanoma and NMSC and the impact of skin cancer on health care services. Furthermore, we underline the pressing need for improved registration policies, especially for NMSC, and lastly, we refer to the ongoing primary and secondary prevention strategies and their outcomes so far.

PP, LP, PR and dermatitis show specific dermoscopic patterns that may aid their clinical diagnosis. Certain combinations of dermoscopic features can reliably predict the diagnosis of PP.

Skin cancer, including both melanoma and non-melanoma, is the most common type of malignancy in the Caucasian population. Firstly, we review the evidence for the observed increase in the incidence of skin cancer over recent decades, and investigate whether this is a true increase or an artefact of greater screening and over-diagnosis. Prevention strategies are also discussed. Secondly, we discuss the complexities and challenges encountered when diagnosing and developing treatment strategies for skin cancer. Key case studies are presented that highlight the practic challenges of choosing the most appropriate treatment for patients with skin cancer. Thirdly, we consider the potential risks and benefits of increased sun exposure. However, this is discussed in terms of the possibility that the avoidance of sun exposure in order to reduce the risk of skin cancer may be less important than the reduction in all-cause mortality as a result of the potential benefits of increased exposure to the sun. Finally, we consider common questions on human papillomavirus infection.

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.