The 2020 International Alliance for the Control of Scabies Consensus Criteria for the Diagnosis of Scabies.

BACKGROUND: Scabies is a common parasitic skin condition that causes considerable morbidity globally. Clinical and epidemiological research for scabies has been limited by a lack of standardization of diagnostic methods. OBJECTIVES: To develop consensus criteria for the diagnosis of common scabies that could be implemented in a variety of settings. METHODS: Consensus diagnostic criteria were developed through a Delphi study with international experts. Detailed recommendations were collected from the expert panel to define the criteria features and guide their implementation. These comments were then combined with a comprehensive review of the available literature and the opinion of an expanded group of international experts to develop detailed, evidence-based definitions and diagnostic methods. RESULTS: The 2020 International Alliance for the Control of Scabies (IACS) Consensus Criteria for the Diagnosis of Scabies include three levels of diagnostic certainty and eight subcategories. Confirmed scabies (level A) requires direct visualization of the mite or its products. Clinical scabies (level B) and suspected scabies (level C) rely on clinical assessment of signs and symptoms. Evidence-based, consensus methods for microscopy, visualization and clinical symptoms and signs were developed, along with a media library. CONCLUSIONS: The 2020 IACS Criteria represent a pragmatic yet robust set of diagnostic features and methods. The criteria may be implemented in a range of research, public health and clinical settings by selecting the appropriate diagnostic levels and subcategories. These criteria may provide greater consistency and standardization for scabies diagnosis. Validation studies, development of training materials and development of survey methods are now required. What is already known about this topic? The diagnosis of scabies is limited by the lack of accurate, objective tests. Microscopy of skin scrapings can confirm the diagnosis, but it is insensitive, invasive and often impractical. Diagnosis usually relies on clinical assessment, although visualization using dermoscopy is becoming increasingly common. These diagnostic methods have not been standardized, hampering the interpretation of findings from clinical research and epidemiological surveys, and the development of scabies control strategies. What does this study add? International consensus diagnostic criteria for common scabies were developed through a Delphi study with global experts. The 2020 International Alliance for the Control of Scabies (IACS) Criteria categorize diagnosis at three levels of diagnostic certainty (confirmed, clinical and suspected scabies) and eight subcategories, and can be adapted to a range of research and public health settings. Detailed definitions and figures are included to aid training and implementation. The 2020 IACS Criteria may facilitate the standardization of scabies diagnosis.

'Wake sign': an important clue for the diagnosis of scabies.

Japan is currently experiencing many outbreaks of scabies, occurring mainly in long-term care facilities. Scabies burrows, the only pathognomonic lesion for scabies, often occur on the creases of the palms, and are followed by a pattern of scale reminiscent of the 'wake' left on the surface of water by a moving bird or a ship (wake sign).(1-4) The wake sign is useful because (i) it is specific for scabies, (ii) it is sufficiently large to be found by the naked eye and (iii) it points towards the location of the mite and its products. Examination of patients' palms to look for this sign is a simple and efficient way to make a diagnosis of scabies throughout the course of an infestation.

Effects of small concentrations of isoflurane on some psychometric measurements.

We have investigated the effects of 9.5% and 14.1% MAC concentrations of isoflurane on some psychometric measurements. Both concentrations depressed peak saccadic velocity (P < 0.01), choice reaction time (P < 0.05) and visual analogue scores for sedation (P < 0.05), but not the critical flicker fusion threshold. The incidence of errors in saccade tasks increased in a dose-related fashion, which made analysis of peak saccadic velocity less accurate at more than 10% MAC. The percentage error itself was an indicator of the depth of sedation. All the objective measures correlated highly with the estimated brain tension of isoflurane (r2 = 0.86-0.96), but not the visual analogue score for sedation (r2 = 0.51). This suggests that a combination of peak saccadic velocity, percentage error and choice reaction time is a potentially useful batch of tests to measure recovery from anaesthesia.

Tramadol: pain relief by an opioid without depression of respiration.

Two independent clinical trials were conducted simultaneously. In one, tramadol and pethidine were compared in 30 patients by patient-controlled analgesia during the first 24 h following abdominal surgery. The mean 24 h consumption of tramadol and pethidine was 642 mg and 606 mg respectively, giving a potency estimate of tramadol relative to pethidine of 0.94 (95% confidence interval 0.72-1.17). In the second trial, the effect on respiration of three doses of tramadol (0.5, 1.0, and 2.0 mg.kg-1) was compared with that of morphine sulphate (0.143 mg.kg-1) by intravenous injection during stable halothane anaesthesia. At approximately 1.5 times the equipotent dose, as estimated from the first trial, tramadol transiently depressed the rate of respiration but had no effect on end-tidal carbon dioxide tension. Morphine caused apnoea or considerable depression of ventilation. The results suggest that mechanisms other than opioid receptor activity play a significant role in the analgesia produced by tramadol.

Effects of low concentrations of cyclopropane and halothane on peak velocity of saccadic eye movements.

We have investigated the effect of 4.7 and 8.8% MAC of cyclopropane, and 5.3 and 9.3% MAC of halothane on the peak velocity of saccadic eye movements (PSV) in six healthy volunteers. Both concentrations of cyclopropane and halothane significantly depressed PSV (P less than 0.01) compared with air, in a dose-related fashion. Halothane depressed PSV significantly more than cyclopropane (P less than 0.05). PSV returned to baseline within 5 min after discontinuation of the agents. There was no significant difference between cyclopropane, halothane and air in subjective assessment of sedation.

Pregnancy associated with Gorlin's syndrome.

A pregnant woman with Gorlin's syndrome presented for the removal of malignant ovarian tumours. The main problem encountered by the anaesthetists was an unexpected increase in arterial blood pressure. This was most probably associated with surgical manipulation of the ovaries with an increase in prorenin/renin production.