Blue, grey, and black colouration

2020 ◽  
pp. 509-514

Normal ethnic skin colouration is due to melanin in the skin. However, in this short chapter abnormal blue, grey, or black changes in skin colour, both localized or generalized, are discussed and illustrated by a few clinical images. The Mongolian blue spot that occurs as a physiological change in the skin of the majority of Asian, Black, and Chinese infants is due to melanin. It is uncommon in Caucasian skin types and not always recognized. A good illustration of the relatively common blue naevus is provided and much rarer examples discussed such as naevus of Ota, naevus of Ito, and alkaptonuria. In addition to melanin, other chromophores deposited in the skin may appear blue or black, such as haemoglobin or rarely drug deposits. The popularity of tattoos and associated problems are also mentioned.

2008 ◽  
Vol 39 (1) ◽  
pp. 28
Author(s):  
DAMIAN MCNAMARA
Keyword(s):  

Author(s):  
Hiroo Kimura ◽  
Akira Toga ◽  
Taku Suzuki ◽  
Takuji Iwamoto

Abstract Background Fracture-dislocations of all four ulnar (second to fifth) carpometacarpal (CMC) joints are rare hand injuries and frequently overlooked or missed. These injuries can be treated conservatively when closed reduction is successfully achieved, though they are sometimes irreducible and unstable. Case Description We report the case of a 17-year-old boy involved in a vehicular accident. Clinical images showed dorsal dislocation of all four ulnar CMC joints of the left hand associated with a fracture of the base of the fourth metacarpal. Although closed reduction was attempted immediately, the affected joints remained unstable and easily redislocated. Therefore, we performed open reduction and percutaneous fixation of all ulnar CMCs. He showed excellent recovery after 1 year postoperatively, reported no pain, and demonstrated complete grip strength and range of motion of the affected wrist and fingers. Literature Review Accurate clinical diagnosis of this lesion is difficult because of polytrauma, severe swelling masking the dislocated CMC joint deformity, and overlapping of adjacent metacarpals and carpal bones on radiographic examination. As for the treatment strategy, it has yet to obtain a consensus. Some reports value open reduction to guarantee anatomical reduction, and it is definitely needed in the patients with interposed tissues to be removed or with subacute and chronic injuries. Clinical Relevance Delayed diagnosis or treatment could lead to poor outcomes. Therefore, surgeons must be aware that precise preoperative assessment is critical, and anatomical open reduction of interposed bony fragments, like our case, may be required even in an acute phase.


2016 ◽  
Author(s):  
Jaya Sujatha ◽  
Gopal Kothandapani ◽  
Lucy Evans ◽  
Gossiel Fatma ◽  
Jennifer Walsh ◽  
...  
Keyword(s):  

2020 ◽  
Vol 2020 (1) ◽  
pp. 60-64
Author(s):  
Altynay Kadyrova ◽  
Majid Ansari-Asl ◽  
Eva Maria Valero Benito

Colour is one of the most important appearance attributes in a variety of fields including both science and industry. The focus of this work is on cosmetics field and specifically on the performance of the human visual system on the selection of foundation makeup colour that best matches with the human skin colour. In many cases, colour evaluations tend to be subjective and vary from person to person thereby producing challenging problems to quantify colour for objective evaluations and measurements. Although many researches have been done on colour quantification in last few decades, to the best of our knowledge, this is the first study to evaluate objectively a consumer's visual system in skin colour matching through a psychophysical experiment under different illuminations exploiting spectral measurements. In this paper, the experiment setup is discussed and the results from the experiment are presented. The correlation between observers' skin colour evaluations by using PANTONE Skin Tone Guide samples and spectroradiometer is assessed. Moreover, inter and intra observer variability are considered and commented. The results reveal differences between nine ethnic groups, between two genders, and between the measurements under two illuminants (i.e.D65 and F (fluorescent)). The results further show that skin colour assessment was done better under D65 than under F illuminant. The human visual system was three times worse than instrument in colour matching in terms of colour difference between skin and PANTONE Skin Tone Guide samples. The observers tend to choose lighter, less reddish, and consequently paler colours as the best match to their skin colour. These results have practical applications. They can be used to design, for example, an application for foundation colour selection based on correlation between colour measurements and human visual system based subjective evaluations.


2006 ◽  
Author(s):  
Gary J. Brauner
Keyword(s):  

2020 ◽  
Author(s):  
Xiaoyu He ◽  
Juan Su ◽  
Guangyu Wang ◽  
Kang Zhang ◽  
Navarini Alexander ◽  
...  

BACKGROUND Pemphigus vulgaris (PV) and bullous pemphigoid (BP) are two rare but severe inflammatory dermatoses. Due to the regional lack of trained dermatologists, many patients with these two diseases are misdiagnosed and therefore incorrectly treated. An artificial intelligence diagnosis framework would be highly adaptable for the early diagnosis of these two diseases. OBJECTIVE Design and evaluate an artificial intelligence diagnosis framework for PV and BP. METHODS The work was conducted on a dermatological dataset consisting of 17,735 clinical images and 346 patient metadata of bullous dermatoses. A two-stage diagnosis framework was designed, where the first stage trained a clinical image classification model to classify bullous dermatoses from five common skin diseases and normal skin and the second stage developed a multimodal classification model of clinical images and patient metadata to further differentiate PV and BP. RESULTS The clinical image classification model and the multimodal classification model achieved an area under the receiver operating characteristic curve (AUROC) of 0.998 and 0.942, respectively. On the independent test set of 20 PV and 20 BP cases, our multimodal classification model (sensitivity: 0.85, specificity: 0.95) performed better than the average of 27 junior dermatologists (sensitivity: 0.68, specificity: 0.78) and comparable to the average of 69 senior dermatologists (sensitivity: 0.80, specificity: 0.87). CONCLUSIONS Our diagnosis framework based on clinical images and patient metadata achieved expert-level identification of PV and BP, and is potential to be an effective tool for dermatologists in remote areas in the early diagnosis of these two diseases.


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