Bullous Erythema Migrans: A Blistering Lyme Disease Rash
Lyme disease rashes are not always flat or bull’s-eye shaped.
Some patients develop blistering erythema migrans lesions.
Bullous Lyme disease may lead to delayed diagnosis and treatment.
Lyme disease can present with several atypical erythema migrans variants including urticarial, linear, granulomatous, and bullous lesions.
As this case series highlights, “several erythema migrans variants have been reported, which may result in misidentification as well as delayed diagnosis and treatment.”1
Bullous Erythema Migrans Is an Atypical Lyme Disease Rash
In their article, “Vesiculobullous Lyme disease: A case series,” the authors describe 3 cases in which erythema migrans presented as a blistering rash, also referred to as bullous erythema migrans.
Typically, an erythema migrans rash is more likely to present as a flat expanding lesion.
All 3 patients developed rapidly progressive bullous lesions along with fatigue, malaise, or fever.
Three Cases of Blistering Lyme Disease Rash
Initially, the lesions were attributed to Sweet syndrome, herpes simplex virus infection, varicella-zoster virus infection, spider bites, or atypical Lyme disease.
Case 1: A 54-year-old woman presented with an enlarging red lesion that progressively darkened. The authors described “a 10-cm edematous purpuric plaque with vesiculobullous.”
Case 2: A 49-year-old woman developed an enlarging lesion involving the posterior ankle. The lesion was described as “a 9-cm vesiculobullous plaque with erythema.”
Case 3: A 65-year-old woman presented with a red, swollen, painful plaque involving the flank.
To review the case reports and rash photographs, click here.
Bullous Lyme Disease May Be Difficult to Diagnose
In all 3 cases, Lyme disease testing was ultimately positive and the patients improved with treatment.
However, diagnosing bullous erythema migrans can be challenging because Lyme disease testing may not yet be positive when the rash first appears.
In addition, histopathologic findings associated with bullous erythema migrans may overlap with several inflammatory or infectious skin disorders.
“Histopathologic features of Lyme disease often include a superficial and deep perivascular and interstitial infiltrate consisting of lymphocytes and plasma cells, and may include eosinophils and neutrophils,” the authors explained.
For additional discussion on atypical Lyme disease rashes, see Lyme disease symptoms guide.
Clinicians Should Consider Lyme Disease in Bullous Lesions
“Clinicians in Lyme endemic areas should be aware that Lyme disease might exhibit a broad range of clinical and histologic findings, including bullous presentations.”
The authors recommend clinicians maintain a low threshold for considering Lyme disease in the differential diagnosis of bullous lesions in endemic regions.
They also emphasize the importance of empiric treatment and follow-up Lyme serologies when clinical suspicion remains high.
FAQ: Bullous Erythema Migrans
Can Lyme disease cause a blistering rash?
Yes. Lyme disease may occasionally present with a blistering or bullous erythema migrans rash rather than the classic flat expanding lesion.
What is bullous erythema migrans?
Bullous erythema migrans is an atypical Lyme disease rash characterized by blistering skin lesions that may resemble viral infections, inflammatory skin disorders, or spider bites.
Related Articles:
Lyme disease skin rash puzzles doctors, leads to misdiagnosis
References:
- Doughty H, O’Hern K, Barton DT, Carter JB. Vesiculobullous Lyme disease: A case series. JAAD Case Rep. 2022;24:56-58. doi:10.1016/j.jdcr.2022.04.001
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
My rash presented itself as a huge hour glass shape all over my torso. My primary care physician diagnosed me with a fungus. I told him he was wrong and to test my for Lyme. Sure enough my bloodwork confirmed my suspicions.