Risk Factors for Seborrhoeic Dermatitis Flares: Case-control and Case-crossover Study.

Patients with flares of seborrhoeic dermatitis were compared with control outpatients seen during the same time-period in a case-control study, and with themselves while in remission in a case-crossover study. All patients consulted the same office-based dermatologist. During the study period, 189 cases and 189 controls were included in the case-control study, and 81 cases in the case-crossover study. Multivariate analysis was performed. Case-control study results were the following: past history of tobacco consumption (odds ratio (OR) 2.2 (95% confidence interval (CI) 1.1-4.6)), conflict as a dispute during the past month (OR 10.6 (95% CI 1.0-114.3)), alcohol consumption on a regular basis (OR 10.2 (95% CI 2.0-52.6)), and higher level of stress during the past month (OR 8.2 (95% CI 3.4-19.9)). Case-crossover study results were the following: higher level of stress during the past month (OR 4.5 (1.7-12.2)), association borderline significant for higher level of alcohol consumption (OR 5.4 (0.8-34.9)). These risk factors for flares of seborrhoeic dermatitis should be taken into account carefully in the daily management of seborrhoeic dermatitis.

Rotating Circular Micro-Platform with Integrated Waveguides and Latching Arm for Reconfigurable Integrated Optics.

This work presents a laterally rotating micromachined platform integrated under optical waveguides to control the in-plane propagation direction of light within a die to select one of multiple outputs. The platform is designed to exhibit low constant optical losses throughout the motion range and is actuated electrostatically using an optimized circular comb drive. An angular motion of ±9.5° using 180 V is demonstrated. To minimize the optical losses between the moving and fixed parts, a gap-closing mechanism is implemented to reduce the initial air gap to submicron values. A latch structure is implemented to hold the platform in place with a resolution of 0.25° over the entire motion range. The platform was integrated with silicon nitride waveguides to create a crossbar switch and preliminary optical measurements are reported. In the bar state, the loss was measured to be 14.8 dB with the gap closed whereas in the cross state it was 12.2 dB. To the authors' knowledge, this is the first optical switch based on a rotating microelectromechanical device with integrated silicon nitride waveguides reported to date.

First prospective study of the recognition process of melanoma in dermatological practice.

BACKGROUND: Early detection is crucial to improve melanoma prognosis. Different diagnostic guides such as the ABCD rule (asymmetry [A], irregularity of borders [B], unevenness of distribution of color [C], and diameter [D]) have been proposed to identify melanoma, but their efficacy in real life is questionable. We investigated the recognition process of melanoma by dermatologists to use as a model to improve self-detection in the general population and to train students and general practitioners. OBJECTIVES: To understand the major principles of the recognition process of nevi and melanoma unconsciously used by dermatologists. DESIGN: Prospective survey recording the immediate perceptions of dermatologists of the morphologic features of the lesion and intuitive diagnostic opinion about 4036 consecutive resected nevi and melanoma. SETTING: One hundred thirty-five volunteer dermatologists in their daily practices. MAIN OUTCOME MEASURES: Perceptions of the image best explaining the diagnostic opinion and best predicting the final diagnosis by univariate and multivariate analysis. RESULTS: The immediate diagnostic opinion of the dermatologist is mainly explained by an unconscious reference to the overall pattern compared with the common nevi, but also compared with the other nevi of the individual (the "ugly duckling sign"). The dermatologist's ability to discriminate between nevi and melanoma relies on the assessment of the overall pattern, the ugly duckling sign, and the knowledge of a recent change. A separate or combined analysis of individual morphologic criteria such as ABCD does not seem to play a major role in this recognition process. CONCLUSIONS: Persons most skilled at the clinical detection of melanoma seem to unconsciously rely on cognitive (overall pattern) and comparative (ugly duckling sign) processes rather than an algorithm of morphologic criteria (ABCD). These concepts could be tested in the medical training of general practitioners and education of the general population, where they might be more efficient than algorithms such as the ABCD criteria.