Lyme disease is the most common vector-borne illness in the United States.1 Caused by the bacteria Borrelia burgdorferi sensu lato and spread through infected tick bites, it affects an estimated 476,000 Americans each year.1,3

Yet the burden of Lyme disease, particularly the experience of a timely diagnosis, isn’t shared equally.

Despite its prevalence, the face of Lyme disease in public health data is overwhelmingly white. In the United States, surveillance data shows that over 90% of Lyme disease cases with reported race occur in people who identify as white.4 At first glance, these data seem to reflect the demographics of where Lyme disease occurs most commonly, predominantly white areas in the Northeast and Midwest.2,4

But new research points to deeper inequities. People of color, especially those who identify as Black or African American, are more likely to develop more severe Lyme disease compared to their white counterparts.

A New Lens Through Medicaid and Medicare Data

A recent study in Emerging Infectious Diseases brings these disparities into sharp focus. The study used data from administrative claims from both Medicaid and Medicare beneficiaries in 16 high-incidence states from 2016 until 2021. Using strict criteria for inclusion (at least one Lyme disease diagnosis code and a prescription for appropriate antibiotics within 30 days of diagnosis), researchers identified thousands of Lyme disease cases — 64,711 in Medicaid and 103,824 in Medicare.4

But compared to white beneficiaries, people of color were much more likely to have disseminated Lyme disease at the time of diagnosis.4 Disseminated Lyme disease can develop when the initial infection isn’t recognized or treated — as a result, a person may have symptoms reflecting the infection’s impact on various organ systems.1 For example, arthritis is one of the most common symptoms of late-stage Lyme disease.3 Other, newer symptoms, such as irregular heartbeat or vision loss, may also appear months or years after the initial infection.1,2,3

People of color were also more likely to be hospitalized at diagnosis for Lyme disease. These findings are particularly stark among children. For example, among Medicaid beneficiaries aged 18 and under, Black children had a 2.35 times higher prevalence of disseminated disease and were 2.57 times more likely to be hospitalized at diagnosis compared to white beneficiaries. These trends continue among adults and Medicare beneficiaries, although the ratios are slightly lower.4

Although most Lyme disease cases in the United States are diagnosed during the months when ticks are most active (June and July), this study also found that Black/African American people are more likely to be diagnosed from December through February than the summer months.4

These patterns suggest significant delays in recognizing Lyme disease in people of color.4

The Rash That’s Easy to Miss

Lyme disease can be difficult to diagnose. For example, Lyme disease often presents with nonspecific or vague symptoms, such as headache or muscle aches and pains.5 Also, people with the same infection may experience different signs since Lyme disease has a wide range of signs and symptoms.

One of the most recognizable signs of Lyme disease is the erythema migrans (EM) rash that can have a range of appearances, including the classic target bull's-eye appearance that appears in about 80% of cases.6 On lighter skin, EM is typically easier to see, appearing red and inflamed. However, on darker skin tones, the rash might be harder to diagnose.1 Healthcare providers might have difficulty seeing and recognizing the rash on darker skin, resulting in missed or delayed diagnosis.4

When clinicians don’t recognize EM early, the bacteria has more time to spread. Disseminated Lyme disease can attack multiple organ systems, including the neurological and musculoskeletal systems, potentially leading to severe symptoms such as facial palsy or arthritis.2,6 Patients at this stage are also more likely to require hospitalization.4

Even when a clinician makes a correct diagnosis, treatment can be tough. In one study, roughly one-third of clinicians didn’t know the recommended treatment approach for patients with nonspecific Lyme symptoms, a notorious challenge.7

Why These Disparities Matter

Delayed diagnosis often means delayed treatment, which can, in turn, make treatment less effective. A 2023 study found that it took Black individuals an average of 35 days to receive Lyme disease-appropriate antibiotics, while white patients waited an average of only seven days. Additionally, 16.2% of Black patients received inappropriate antibiotics first, potentially prolonging illness or worsening outcomes.8

And that’s a big deal — missing appropriate treatment early can lead to greater disability, higher medical costs, longer recovery times, and a diminished quality of life.

Taking Steps Toward Health Equity

There’s no one-size-fits-all solution for addressing inequities in Lyme disease diagnosis. It will require a multipronged approach. For example, people in areas where Lyme disease is more common could benefit more from targeted messaging and public health education.9

Clinicians need better training on how Lyme disease presents across diverse skin tones. Recognizing EM on darker skin shouldn’t be exceptional. Current Lyme disease prevention efforts typically use light-skinned imagery; they should expand to include examples of how the rash appears on darker skin, promoting awareness among clinicians as well as the general public.

Administrative data like Medicaid and Medicare claims can uncover disparities that traditional surveillance systems miss. Incorporating this information into health assessments could strengthen recognition. Some healthcare systems have implemented algorithms to standardize care among different specialties — similar tools could help flag patients at risk for Lyme disease.7

Healthcare organizations could also:

  • Regularly update clinicians on regional tick-borne disease trends.
  • Provide guidance on appropriate Lyme testing and ordering workflows within electronic medical records.7
  • Expand bias training and pattern-recognition education for frontline providers.

Lyme disease doesn’t discriminate. But the ways it’s recognized, treated, and understood often do. For many people of color, awareness of Lyme disease only comes after serious symptoms emerge. The disease itself may be common, but the cost of overlooking it in communities of color is far greater.