Lyme Disease Rash: What Does It Really Look Like?

Learn all about Lyme disease and rashes in this informative video. In this video, I discuss the various appearances of a Lyme Disease rash, also known as an erythema migrans (EM) rash.

Many people assume that a Bull’s-eye or erythema migrans (EM) rash is a common manifestation of Lyme disease. And that the lack of a rash confirms a person does not have the disease. This is far from the truth.

EM rash identification remains a challenge because it often takes on a variety of appearances, according to a study by Burlina and colleagues.

“Only 20% of patients with an EM [rash] in the United States present with lesions that have the central clearing of a classic target lesion (“ring-within-a-ring” or “bull’s eye”).¹

Instead, “the majority of EM lesions appear uniformly red or bluish-red in color and lack central clearing.”

Unfortunately, a Lyme disease rash may look like lesions found in other disorders. For instance, patients with Lyme disease may be misdiagnosed as having a cellulitis rash. The treatment for cellulitis is not necessarily effective for Lyme disease.

Furthermore, between 4% and 8% of Lyme disease rashes present with a central blistering. These cases can be misdiagnosed as shingles, a viral infection that causes blistering and is treated with anti-viral medications. Shingles treatment is not effective in treating Lyme disease.

READ MORE: It wasn’t shingles. It was Lyme disease.

Lastly, about 20% of patients have multiple EM rashes at the time of diagnosis due to the Lyme spirochete disseminating to other areas of the body. This presentation can be confused with erythema multiforme or other skin disorders.

In practice, I treat with an antibiotic if there is uncertainty, as the consequences of missing a diagnosis of Lyme disease can be serious. If the rash is questionable, I often treat with antibiotics that would be effective for either Lyme disease or another possible condition. For example, I might treat a patient with a rash that could be cellulitis or Lyme disease with an antibiotic that works for both such as cefuroxime rather than Keflex.

I typically treat these cases longer if Lyme disease is a possibility. Finally, I have also treated patients with a combination of an anti-viral medication (Valtrex) and cefuroxime if I am unsure whether the rash is related to shingles or Lyme disease.