Can skin color affect medical students’ ability to diagnose Lyme disease?

Multiple studies have demonstrated that a patient’s race can affect the diagnostic tests offered to that patient. One study found African American patients who presented with chest pain were offered fewer tests than non-African Americans, according to Dodd and colleagues. [1]

So, how prepared are medical students to properly diagnose patients of all races and ethnicities? Do they have the diagnostic ability and confidence in making a diagnosis, such as Lyme disease, for individuals with non-white skin color?

In the study, “The impact of patient skin colour on diagnostic ability and confidence of medical students,” Dodd et al.¹ examined whether medical students’ confidence and ability in diagnosing various clinical conditions and signs is affected by a patient’s skin colour.

An online quiz with photographs provided insight into students’ diagnostic abilities and confidence. The study also used case vignettes to understand students’ cognitive reasoning processes.

Are medical students prepared to properly diagnose patients of all races and ethnicities?

The authors offered an online quiz to 185 medical students. The quiz contained 24 medical photographs of 12 clinical conditions and signs, relevant to the students’ curriculum: shingles, Kawasaki disease, cellulitis, pityriasis versicolour, Lyme disease, central cyanosis, eczema, urticaria, chickenpox, meningococcal disease, jaundice and Henoch-Schönlein purpura.

The students were presented with an image from an individual with white skin (WS) and another image from an individual with non-white skin (NWS). The NWS images included Black and Asian racial groups and different gradations of color.

Investigators found that, “Students were significantly more likely to accurately diagnose five of the 12 clinical presentations (shingles, cellulitis, Lyme disease, eczema and meningococcal disease) on WS compared to NWS.”

The diagnostic challenges are better understood when reviewing the participants’ comments:

“… I feel like on darker skin tones, sometimes it’s the opposite, and sometimes you just don’t notice the erythema [migrans rash] …”

“So, I think the lack of representation of darker skin in the textbooks can be detrimental when it comes to like education and [understanding] what the rashes may look like on darker skin tones.”

“So, I think that, especially in, like, medical school textbooks and online resources, we often only see images of, kind of, white Caucasian people with skin conditions …”

The participants had several suggestions for improving their confidence in diagnosing patients of all skin colors:

“I think every time I’m shown a diagnosis on a lighter skin tone, if I was shown the exact same diagnosis on a darker skin tone [it would be helpful].”

“… in an ideal world, they could show it on as many different skin colors as possible, just to highlight the differences.”

“Probably just more experience and more practice, and in terms of when we get taught about skin conditions.”

“… I guess just being prompted to pay more attention for things on darker skin tones.”

The authors concluded:

Students were “significantly more capable of diagnosing several common clinical presentations (shingles, cellulitis, Lyme disease, eczema and meningococcal disease) on [patients with white skin] compared to [those with non-white skin].”

The authors noted limitations to their study, including the small non-representative sample.

“One further limitation of this study was the lack of images that were available for use in constructing the vignettes for this study, especially for the NWS clinical pictures, this itself illustrates the problem students face when trying to educate themselves about clinical presentations in patients with different skin tones.”

The authors published their study to examine “the potential for unconscious racial biases in clinical medicine.”