[Prurigo pigmentosa: Case report of a German adolescent]. / Prurigo pigmentosa: Fallbericht eines deutschen Jugendlichen.

Prurigo pigmentosa is an inflammatory dermatosis that rarely occurs in Europe and mostly affects young women. Here, we describe the typical clinical and dermoscopic criteria so that therapy can be initiated as early as possible. The 17-year-old patient presented here shows that this disease can also be observed in Western Europe and in men, and that doxycycline is a very effective treatment option.

Collective human intelligence outperforms artificial intelligence in a skin lesion classification task.

BACKGROUND AND OBJECTIVES: Convolutional neural networks (CNN) enable accurate diagnosis of medical images and perform on or above the level of individual physicians. Recently, collective human intelligence (CoHI) was shown to exceed the diagnostic accuracy of individuals. Thus, diagnostic performance of CoHI (120 dermatologists) versus individual dermatologists versus two state-of-the-art CNN was investigated. PATIENTS AND METHODS: Cross-sectional reader study with presentation of 30 clinical cases to 120 dermatologists. Six diagnoses were offered and votes collected via remote voting devices (quizzbox®, Quizzbox Solutions GmbH, Stuttgart, Germany). Dermatoscopic images were classified by a binary and multiclass CNN (FotoFinder Systems GmbH, Bad Birnbach, Germany). Three sets of diagnostic classifications were scored against ground truth: (1) CoHI, (2) individual dermatologists, and (3) CNN. RESULTS: CoHI attained a significantly higher accuracy [95 % confidence interval] (80.0 % [62.7 %-90.5 %]) than individual dermatologists (75.7 % [73.8 %-77.5 %]) and CNN (70.0 % [52.1 %-83.3 %]; all P < 0.001) in binary classifications. Moreover, CoHI achieved a higher sensitivity (82.4 % [59.0 %-93.8 %]) and specificity (76.9 % [49.7 %-91.8 %]) than individual dermatologists (sensitivity 77.8 % [75.3 %-80.2 %], specificity 73.0 % [70.6 %-75.4 %]) and CNN (sensitivity 70.6 % [46.9 %-86.7 %], specificity 69.2 % [42.4 %-87.3 %]). The diagnostic accuracy of CoHI was superior to that of individual dermatologists (P < 0.001) in multiclass evaluation, with the accuracy of the latter comparable to multiclass CNN. CONCLUSIONS: Our analysis revealed that the majority vote of an interconnected group of dermatologists (CoHI) outperformed individuals and CNN in a demanding skin lesion classification task.

Waldenström macroglobulinaemia presenting as tingling ulcers on the feet.

A 56-year-old man presented with tingling ulcers on the feet. On further skin examination, papules on the knees were observed. Biopsies revealed extravascular eosinophilic deposits of IgM, and Waldenström macroglobulinaemia was diagnosed. The skin manifestations have resolved with chemotherapy. Peripheral neuropathy and storage papules are rare manifestations of Waldenström's macroglobulinaemia.