Black Health
Emergent Infectious disease

Mind the Gap atlas

Erythema migrans (Lyme disease) on Black skin

Key cue: Don't look for a 'bright red bullseye' on Black skin. Look for an expanding patch that's darker, duskier, or bruise-coloured.

Erythema migrans is the expanding skin lesion that appears at the site of a tick bite infected with Borrelia burgdorferi (Lyme disease). It is the single most important early sign; recognising it and starting antibiotics prevents most later complications, including Lyme carditis, neurological Lyme, and Lyme arthritis.

What it actually looks like

Textbook says

Textbooks show a circular or oval red patch that expands outward over days, often with a central area of clearing producing the classic 'bullseye'. The rash is typically described as warm, painless, minimally itchy, and 5 cm or larger within a week. Standard diagnostic criteria use this bright-red-on-pink appearance as the reference.

On Black skin

On darker skin the rash is often not red. Case series in the CDC Morbidity and Mortality Weekly Report and in the Journal of the American Academy of Dermatology describe erythema migrans on Black skin as:

  • Violaceous (purple), dusky brown, or bruise-coloured rather than red.
  • The central clearing that produces the bullseye is much subtler or absent, so the lesion may look like a uniform darker patch instead of a target.
  • Often misread as a bruise, an allergic reaction, cellulitis, or a spider bite — delaying diagnosis.

CDC surveillance has found Black patients are significantly less likely to be diagnosed at the erythema migrans stage and more likely to present with disseminated Lyme (Lyme arthritis, carditis, or Bell's palsy) — consistent with early-stage lesions being missed on exam.

What to look for

  • An expanding skin patch that wasn't there before, in an area you recently spent time outdoors in a Lyme-endemic region (Northeast US, Upper Midwest, parts of California, Europe).
  • Size: usually > 5 cm after a few days; keeps growing.
  • Mild warmth; typically not painful and not very itchy.
  • Look at the lesion in good light — check whether it is a single shade or has a darker rim and lighter centre (the ring, however subtle).
  • Check for accompanying fever, fatigue, headache, joint or muscle aches.

Emergent — call 911 or go to the ER

See a clinician the same day or next day. Early Lyme responds completely to a short course of doxycycline, amoxicillin, or cefuroxime — treatment should not wait for blood tests (antibody tests are often negative in the first few weeks). Untreated disease can progress to carditis (with AV block) or neurological involvement within weeks, so this is an urgent — not a routine — visit. Go to the ER for palpitations, chest pain, fainting, severe headache, or facial droop.

Common misdiagnosis

Erythema migrans on Black skin is often missed or misdiagnosed as a bruise, bug bite reaction, fungal infection (tinea), cellulitis, or drug eruption. Because serology is insensitive early, clinical recognition of the lesion is the single most important step — and that recognition is the most race-sensitive. When unsure, ask a clinician directly: 'Could this be early Lyme?' and photograph the lesion daily to show expansion.

See it for yourself — curated external imagery

We don't host clinical photos here. The links below go to peer-reviewed or open-access sources (Mind the Gap, DermNet NZ, PubMed Central, and similar). Each opens in a new tab.

References

  • Kugeler KJ, Schwartz AM, Delorey MJ, et al. Surveillance for Lyme disease — United States, 2008-2015. MMWR Surveill Summ. 2017;66(22):1-12. PMID: 29120994.
  • Fix AD, Peña CA, Strickland GT. Racial differences in reported Lyme disease incidence. Am J Epidemiol. 2000;152(8):756-9. PMID: 11052554.
  • Stonehouse A, Studdiford JS, Henry CA. An update on the diagnosis and treatment of early Lyme disease: focusing on the bull's eye, you may miss the mark. J Emerg Med. 2010;39(5):e147-51. PMID: 20042305.
  • Mukwende M, Tamony P, Turner M. Mind the Gap. St George's, University of London; 2020.

Medical disclaimer

Educational content only. This is not a substitute for in-person evaluation. If you are worried about yourself or someone you love, see a clinician — and if you are concerned about an emergency sign described here, call 911 or your local emergency number. We do not host clinical imagery; the external references are for reader self-education and are not owned by or affiliated with Black Health.

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