There were two instances this semester that made me think, “This is definitely worth a blog post”. The first was when I noticed the soap dispenser not being able to sense a black glove verses a blue one. The second instance was measuring individuals’ pulse oximetry with a sensor that could not take the measurements of someone with a “darker” skin tone verses others with “lighter” skin tones. How has this affected our healthcare system?
In February of this year, the FDA indicated that skin pigmentation was among one of the variables that can affect pulse oximetry accuracy. Demographic subgroups are required by the FDA to be a part of device testing; however, calibration and confirmation tests are done on those with light skin. The University of Michigan ran a study where levels of hypoxia were measured in ICUs and between Black and White cohorts. Black patients had a higher percentage of being under-detected for hypoxia.
A study was performed on individuals with a range of skin tones from dark, intermediate, and light along with different types of pulse oximetry equipment comparing clip-on versus adhesive styles. Pulse oximetry equipment uses an infrared technology to get a pulse reading, so theoretically you should get a pulse oximetry measurement that is independent of skin color. However, the path of light being used will be affected by different variations of skin color. Deoxyhemoglobin and melanin are light absorbers; therefore, the concentration of skin pigmentation will affect how much light is being absorbed/dispersed to measure hemoglobin levels.
The second study mentioned above was performed in 2007 and claimed that for the previous 20 years, pulse oximetry accuracy was measured only with those of a lighter skin tone. My question is, are we still taking these discrepancies into consideration today? How much regulation is being implemented on making sure these devices are taking accurate readings across all ranges of skin colors?
I believe that this is a matter of justice. It’s more than my darker-skinned partner having to hop from sink to sink because he thinks the faucets with sensors are all damaged (after explaining my skin-tone verses sensors hypothesis, he jokingly said sinks are racists). He would be at a disadvantage if he needed an accurate pulse oximetry reading, but the measurement was inaccurate because of the concentration of melanin that he has. I would like to know how much of this the FDA has taken into consideration and how has it progressed or regressed in improving the accuracy of pulse oximetry devices in regard to skin color. Also, how have companies like Apple, Garmin, and Fitbit considered variations in skin color affecting the accuracy in their health monitoring devices.
Feiner, J. R., Severinghaus, J. W., & Bickler, P. E. (2007). Dark Skin Decreases the Accuracy of Pulse Oximeters at Low Oxygen Saturation: The Effects of Oximeter Probe Type and Gender. Anesthesia & Analgesia, 105(6), S18–S23. https://doi.org/10.1213/01.ane.0000285988.35174.d9
Pulse Oximetry May Be Inaccurate in Patients with Darker Skin. (2021). AJN, American Journal of Nursing, 121(4), 16–16. https://doi.org/10.1097/01.NAJ.0000742448.35686.f9
Sañudo, B., De Hoyo, M., Muñoz-López, A., Perry, J., & Abt, G. (2019). Pilot Study Assessing the Influence of Skin Type on the Heart Rate Measurements Obtained by Photoplethysmography with the Apple Watch. Journal of Medical Systems, 43(7), 195. https://doi.org/10.1007/s10916-019-1325-2
Hi Diem, great post! It’s shocking how many everyday items are tuned to only a single pigment of skin. Upon further research, I was discouraged to find individuals with darker pigmentation were additionally much less likely to receive the correct diagnosis of diseases affecting the integumentary system. Unfortunately, this is largely due to the lack of education medical students receive in diagnosing skin conditions on pigmented skin. A 2020 study discovered only 356 of the 3469 (10.3%) diagnosis pictures in written dermatology textbooks were of dark pigmented skin (Alvarado & Feng, 2020). This disparity between lighter and darker pigmented skins continues after medical school as well, as pictures of darker pigmentation dermatology conferences and resources such as American Academy of Dermatology (AAD) annual meetings comprise a mere 14.9% of all images shown (Perlman et al., 2021).
ReplyDeleteThere is hope for the future in combating this disparity, as a greater awareness of the gap has pushed the creation of new guides such as VisualDx. An online virtual trainer, VisualDx had 2569 pictures of dermatological conditions and diagnoses for darker pigmented skin (Alvarado & Feng, 2020). While still only encompassing 28.5% of all pictures on the program, it’s a drastic increase from the commonly used medical textbooks. Further implementation of programs like VisualDx is essential to train both future and current doctors of the visual differences in skin disorders to for the beneficence of all darker pigmented individuals, as it could prevent further misdiagnosis and provide earlier detection of skin pathologies.
Alvarado, S. M., & Feng, H. (2021). Representation of dark skin images of common dermatologic conditions in educational resources: a cross-sectional analysis. Journal of the American Academy of Dermatology, 84(5), 1427-1431.
Perlman, K. L., Williams, N. M., Egbeto, I. A., Gao, D. X., Siddiquee, N., & Park, J. H. (2021). Skin of color lacks representation in medical student resources: a cross-sectional study. International Journal of Women's Dermatology, 7(2), 195.
Austin, thank you for expanding on this! It's so interesting to find out how much we still don't know in regards to skin pigmentation and proper diagnoses of dermatological manifestations.
ReplyDeleteI agree that it is disheartening, but I love that there is an interest in understanding these differences such as the production of VisualDx. This is something that gives communities hope. I recall reading about a medical student who wanted to know how the same symptoms on a lighter skin tone would manifest on individuals with a darker skin tones.
It makes me excited to see that this student took the initiative to start a project that turned into a book (Mind the Gap: A Handbook of Clinical Signs in Black and Brown Skin) that identifies how symptoms appear on darker skin tones. I've linked the article that was written on him below by the Washington Post. This is such a breakthrough idea for treating patients and I'm curious to see all the different skin pathologies that we can correctly identify now.
https://www.washingtonpost.com/lifestyle/2020/07/22/malone-mukwende-medical-handbook/