Consensus-based protocol for vitiligo photography may improve outcomes
Vitiligo experts compiled a protocol for vitiligo photography to improve outcome assessment, foster collaboration and promote communication with patients regarding treatment outcomes, according to findings published in Journal of the American Academy of Dermatology.
“In order to optimally exploit photography for patient management as well as clinical research, there is an urgent need to promote and adopt standards for achieving consistent, comparable and informative images not only for any given patients over time, but also for groups of patients across different institutions and practice settings,” Nanja van Geel, MD, PhD, from the department of dermatology at Ghent University Hospital in Belgium, and colleagues wrote.
An imaging workshop took place at the Vitiligo International Symposium in November 2018 that identified seven items to consider in the imaging protocol, which was based on information from the Vitiligo Imaging Workshop in April 2018. These seven items were considered the most relevant from the global vitiligo experts:
- general preparation of the patient;
- optimal background for vitiligo photography;
- use of a reference scale;
- patient positioning;
- camera settings; and
- minimum set of photographs for key anatomical regions.
Before taking any photographs, attain patient consent and ensure they understand the photographs will be entered into their medical record, the researchers wrote.
The background or wall for the photo should be composed of a uniform color, a nonreflective surface and consistent in each photograph. The researchers recommend black, dark blue or green, which visualizes skin tones better. A wall or door may be painted in a nonreflective color if space is limited. Additionally, a felt or velour fabric backdrop may be used as long as it is also a nonreflective black or blue.
To scale the photo, the use of a single item with a known size, like a ruler or a standard reference card, is recommended, they wrote.
The use of tape on the floor or a mat can help ensure proper positioning of the patient. The researchers recommend a standardized position according to the Vitiligo Extent Score (VES) images for compatibility with the VES tool. Depending on the camera, the optimal distance between the patient and the camera is 1 m to 1.5 m.
Lighting is an important factor and should be reproducible in every session. Preferably, lighting from either side of the patient is ideal but may not be an option. Darkening the windows or using artificial lights is recommended. Among patients with lighter skin, use UV photography to enhance the contrast between lesional and nonlesional skin. A better option to using a Wood’s lamp and digital camera is a higher-power UVA flash.
Although camera types will vary, the researchers recommend low light sensitivity such as in a digital single-lens reflex camera. The raw file format retains the best image fidelity and is less subject to intentional or accidental corruption, according to researchers.
Although it may be easiest to shoot in the automatic mode, better photographs may be achieved in the programmed automatic mode (P mode). In P mode flash, ISO setting, white balance and exposure compensation are adjustable. In UVA light or flash, the manual setting may be necessary.
Researchers set a minimum of 10 photographs of affected and unaffected areas in clinical practice, preferably at every visit, but most importantly at baseline. In research, at least 15 photographs corresponding to VES images are recommended both at the start and end of the trial. For time points in between, only the affected areas can be photographed.
“These procedures may be integrated into future clinical trials to produce more efficient and reliable interpretation of results,” van Geel and colleagues wrote. “Moreover, it may also provide deep phenotyping in combination with artificial intelligence to analyze big data, relevant information on natural course, patterns and prognosis of vitiligo.” – by Abigail Sutton
Disclosures: van Geel is a consultant and/or investigator for Incyte, Labortoire Génévrier and Pfizer. Please see the study for all other authors’ relevant financial disclosures.