Lyme Disease in Travelers: A Missed Diagnosis Abroad
Lyme disease may be acquired far from where symptoms appear
Atypical rashes and neurologic symptoms can resemble other illnesses
Travel and exposure history may provide the missing diagnostic clue
Lyme disease in travelers is often missed when clinicians in non-endemic regions fail to consider exposure history.
Two cases—one involving neurologic symptoms in Japan and another involving unusual skin lesions in Peru—highlight how easily Lyme disease can be overlooked after a patient leaves the region where the infection was acquired.1,2
A Misleading Presentation in Japan
A woman who had lived in New York for 10 years returned to Japan to visit family. She developed difficulty opening her mouth, fatigue, and facial asymmetry.1
Initially, a neurologist suspected tetanus, a more familiar diagnosis in that clinical setting.
However, closer examination revealed facial paralysis:
- Unilateral mouth drooping
- Inability to close one eye
- Limited jaw opening
This shift in diagnosis changed the clinical trajectory.
The Missing Clue: Travel History
Further questioning revealed a critical detail:
The patient had been bitten by a tick while camping in Pennsylvania approximately 3 months earlier.
She also reported a rash consistent with erythema migrans and a low-grade fever after the exposure.
Despite these clues, Lyme disease was not initially considered because she presented for care in Japan, where clinicians encounter far fewer cases than in the northeastern United States.
Diagnosis and Recovery
The patient ultimately tested positive for Lyme disease.
After 2 weeks of oral minocycline, her symptoms resolved, including:
- Facial weakness
- Fatigue
- Difficulty closing her eye
This case demonstrates how the location where a patient seeks care can influence which diagnoses are initially considered.
A Second Traveler Developed an Atypical Rash
A 2025 case report described a 19-year-old man from Peru who had lived in a wooded area of Maryland between February and July.2
After returning to Peru, he developed abdominal pain and several unusual skin lesions. One was a small crusted lesion on his abdomen with surrounding redness, induration, and poorly defined borders. Another painful red lesion appeared on his leg.
The lesions did not have the familiar bull’s-eye appearance commonly associated with erythema migrans. The patient also did not remember being bitten by a tick.
Because the findings resembled bacterial cellulitis, he was initially treated with oral clindamycin, topical mupirocin, and later cephalexin. When the lesions did not improve, he was hospitalized and received intravenous vancomycin because of concern for a resistant bacterial skin infection.
When Presumed Cellulitis Does Not Improve
Blood and lesion cultures were negative, and the skin findings did not respond as expected to treatment directed at cellulitis.
Clinicians then broadened the differential diagnosis. The patient’s recent residence in Maryland—an area where Lyme disease is endemic—became an important clue.
Serologic testing demonstrated a positive IgM response. A skin biopsy revealed chronic inflammatory changes, and the authors reported detecting spirochetes with a Warthin-Starry stain.
The diagnosis was based on the combined clinical picture, including:
- Recent residence in a Lyme-endemic region
- Wooded exposure during tick season
- Atypical skin lesions
- Lack of improvement with antibiotics directed at cellulitis
- Supporting serologic and biopsy findings
The patient was treated with doxycycline. At the 6-month follow-up, the skin lesions had disappeared, and he reported no remaining symptoms.2
Lyme Disease Rashes Do Not Always Look Like a Bull’s-Eye
Erythema migrans is often depicted as a circular rash with central clearing. However, Lyme disease rashes can vary considerably in shape, color, and appearance.
Reported variations include:
- Uniformly red lesions without central clearing
- Crusted or blistering lesions
- Multiple red patches
- Lesions resembling cellulitis
- Dark or bruised-looking areas
- Rashes with poorly defined borders
This does not mean that every unusual rash or case of cellulitis represents Lyme disease. Bacterial cellulitis is common and may require prompt treatment. However, clinicians may need to reconsider the diagnosis when a presumed skin infection does not improve as expected.
Why Lyme Disease Is Missed Outside Endemic Regions
Clinicians naturally prioritize diseases commonly encountered in their own communities. In non-endemic countries or regions, they may initially focus on:
- Locally prevalent infections
- Autoimmune conditions
- Neurologic disorders
- Malignancy
- Common bacterial skin infections
This geographic bias can delay diagnosis and treatment.
Travelers may become infected while camping, hiking, visiting family, attending summer camp, or staying at a second home. Symptoms may not be recognized until they have returned home.
The relevant question is therefore not only where the patient currently lives, but where the patient traveled or spent time during the weeks preceding the illness.
Travel History Should Include Exposure History
Asking whether a patient remembers a tick bite is not enough. Many people diagnosed with Lyme disease never noticed a tick attachment.
A more useful exposure history may include:
- Recent travel to a Lyme-endemic area
- Time spent in wooded, grassy, or brush-filled environments
- Camping, hiking, gardening, or occupational exposure
- Outdoor exposure during peak tick season
- Pets that may have carried ticks into the home
- Any expanding or otherwise unexplained skin lesion
These questions may also be important when evaluating unexplained Lyme disease symptoms that begin after travel.
Frequently Asked Questions
Can Lyme disease symptoms begin after leaving an endemic area?
Yes. A person may acquire Lyme disease during travel and develop or recognize symptoms only after returning home.
Can Lyme disease be mistaken for cellulitis?
Yes. Some erythema migrans lesions may be uniformly red, tender, crusted, poorly defined, or otherwise resemble cellulitis. However, many other conditions can produce similar skin findings.
Does a Lyme disease rash always look like a bull’s-eye?
No. Erythema migrans may be uniformly red or have an irregular, crusted, blistering, or bruise-like appearance without central clearing.
Does not remembering a tick bite rule out Lyme disease?
No. Many patients with Lyme disease do not remember seeing or removing an attached tick.
Does failure to respond to cellulitis treatment prove Lyme disease?
No. Several conditions can resemble cellulitis. Failure to improve should prompt reassessment and a broader differential diagnosis rather than automatically establishing Lyme disease.
Clinical Takeaway
Clinicians evaluating patients with unexplained neurologic symptoms, fever, or atypical skin lesions should ask about recent travel and possible tick exposure.
A patient may acquire Lyme disease in one region and develop symptoms after arriving in another. The absence of a remembered tick bite or classic bull’s-eye rash should not erase a meaningful exposure history.
Where symptoms appear is not necessarily where the infection was acquired.
Related Articles
Can Lyme Disease Be Diagnosed While Traveling Abroad?
Can Lyme Disease Be Missed?
Lyme Disease Rash Symptoms
Lyme Disease vs. Bell’s Palsy
References
- Seki, M., Watanabe, Y., & Kawabata, H. A case of Lyme disease in a Japanese woman. Infection and Drug Resistance. 2018;11:631–633.
- Salcedo, A. S., Carreras, X., Saavedra, J., et al. Atypical presentation of Lyme disease in a returning traveler: A case report. Tropical Diseases, Travel Medicine and Vaccines. 2025;11:42.
This article is for informational purposes only and is not intended to provide medical advice, diagnosis, or treatment.
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
I couldn’t agree more with the headline, clinicians in foreign countries should consider Lyme disease with symptomatic travelers! This should be louder! These infectious diseases shouldn’t be carried around by any person especially those who are travelling one country to another.