Sequential digital dermoscopic imaging (SDDI) compares surface microscopy images of skin lesions over multiple time points. We utilized a retrospective SDDI cohort to investigate the development of dermoscopic features associated with malignancy in melanoma in situ (MIS). A total of 124 in situ melanomas were assessed from 110 Caucasian patients aged ≥18 years, with ≥2 serial images obtained between 1999 and 2017 and followed for a mean 41 months (3–142). As a positive control group, 58 invasive melanomas from 53 patients were also reviewed. Change in MIS size or number of colours correlated to time (both p < .001). The odds of MIS displaying ≥3 clues to malignancy also correlated to time (OR 5.6–52.1) (p < .05). 75% of in situ melanomas matched a dermoscopic subtype on final imaging. While a clinically significant minority of in situ melanomas were unchanged or lost dermoscopic features, lesions predominantly increased in morphological complexity over time. Longer follow‐up periods allow dermoscopic features associated with malignancy and histopathological progression to develop.

Dermoscopy can be very helpful in the early diagnosis of melanoma and MIS. The Chaos and Clues method is simple to use. Its unambiguous descriptors can be successfully used to describe MIS. The presence of chaos and clues to malignancy (including thick lines, eccentric structureless areas, and blue/grey structures) should raise a red flag and lead to referral or excision.

Background/objectives Bullous pemphigoid (BP) is an uncommon autoimmune bullous disorder, with significant morbidity and mortality. Mortality may be as high as 23.5% in the first year after diagnosis. Clear epidemiologic data across Australasia are lacking. Methods A retrospective, multi‐centred cohort study was designed to determine the incidence and mortality of bullous pemphigoid in New Zealand. Data from all histopathologically diagnosed patients with bullous pemphigoid between 2009 and 2015 from the Auckland region were obtained. Demographics, clinical characteristics and outcome 3 years from diagnosis (until 31 December 2018) were collected. Demographic data were compared against a denominator year‐matched New Zealand Census population. Results One hundred sixty‐one patients had confirmed bullous pemphigoid, with an incidence rate of 3.03/100 000 person‐years [95% CI 2.58–3.54]; 70% were of European ethnicity; 12.4% were Pacific peoples; 11.2% were Asian; and 6.8% were Māori. 45.3% had associated cognitive impairment and/or stroke. In the 3‐year follow‐up, 25% had treatment complications mostly from prednisone therapy. The mortality rate was 40%, highest in the first year of diagnosis, with age at diagnosis a predictor. Conclusion The incidence and mortality rates are comparable to the UK/Northern Europe. Knowledge of the epidemiology of bullous pemphigoid in New Zealand and within an international settling informs the provision of future care and treatments.

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