Suspicion in Endemic Areas
On Long Island, New York, where Lyme disease is endemic, internist Ian Storch, DO, said he sees “a few cases a season.
“We have a lot of people over the summer going to the Hamptons and areas out east for the weekend and tick bites are not uncommon,” he said. “People panic.”
He said one thing it’s important to tell patients is that the tick has to be on the skin for 48-72 hours to transmit the disease. If individuals were in a wooded area and were fine before they got there and the tick was attached for less than 2 days, “they’re usually fine.”
Another issue, Dr. Storch said, is patients sometimes want to get tested for Lyme disease immediately after a tick bite. But the antibody test doesn’t turn positive for weeks, he noted, and you can get a false-negative result. “If you’re worried and you really want to test, you need to wait 6 weeks to do the blood test.”
In his region, he said that although a tick bite is a red flag, he may also suspect Lyme disease when a patient presents with otherwise unexplained joint pain, weakness, lethargy, or fever. “In our area, those are things that would make you test for Lyme.”
He also urged consideration of Lyme in this new age of long COVID. Weakness, fatigue, and lethargy are also classic symptoms of long COVID, he noted. “Keep Lyme disease in your differential because there is a lot of overlap with chronic Lyme disease,” Dr. Storch said.
Discerning Lyme from Southern Tick–Associated Rash Illness
Bonnie M. Word, MD, director of the Houston Travel Medicine Clinic in Texas, where Lyme disease is not endemic, said Lyme disease “will not and should not be on the initial differential diagnosis for those residing in nonendemic areas unless a history of travel to an endemic area is obtained.”
She noted the typical EM rash may not be as distinct or easy to discern on black and brown skin. In addition, she said, EM may have many variations in presentation, such as a crusted center or faint borders, which could lead to a delay in diagnosis and treatment. She suggested consulting the CDC guidance on Lyme disease rashes.
Another challenge in diagnosis, she said, is the patient who presents with what appears to be a classic EM lesion but does not live in a Lyme-endemic area. In Texas, Southern Tick–Associated Rash Illness (STARI) may present with a similar lesion, she said.
“It is transmitted by the Lone Star Tick, which is found in the southeast and south-central US,” Dr. Word said. “However, its habitat is moving northward and westerly,” she said.
Adding Lyme disease to the differential diagnosis is reasonable, she said, if a patient presents with neurologic symptoms “such as a facial palsy, meningitis, radiculitis, and carditis if in addition to their symptoms there is evidence of an epidemiologic link to a Lyme-endemic region.”
She noted that a detailed travel history is important as “Lyme is also endemic in Eastern Canada, Europe, states of the former Soviet Union, China, Mongolia, and Japan.”
Primary care physicians play a critical role in evaluating, diagnosing, and treating most cases of early Lyme disease, thus limiting the number of people who will develop disseminated or late Lyme disease, she said. “The two latter manifestations are most often treated by infectious disease, neurology, or rheumatology specialists.”
Treatment*
Treatment is tailored to the clinical situation, Dr. Schutzer and Dr. Coyle write. A watch-and-wait approach may be appropriate in an asymptomatic but concerned person, even in an endemic area if the person has no known tick bite and no EM lesion.
If there is high risk of an infected ixodid tick bite in a high-incidence area and the tick was attached for at least 36 hours but less than 72 hours, one dose of doxycycline has been recommended as prophylaxis.
When a diagnosis of early nondisseminated Lyme disease is made after observation of an EM lesion, oral antibiotics are typically used to treat for 10 to 14 days. Suggested oral antibiotics and doses are 100 mg of doxycycline twice a day, 500 mg of amoxicillin three times a day, or 500 mg of cefuroxime twice a day, the authors write.
Dr. Schutzer said he hopes the paper serves as a refresher for those physicians who regularly see Lyme disease cases and also helps those newly included in the disease’s spreading regions.
“The earlier you diagnose it, the earlier you can treat it and the better the chance for a favorable outcome,” he said.
Dr. Schutzer, Dr. Coyle, Dr. Storch, and Dr. Word reported no relevant financial relationships.
*This story was updated on August, 2, 2024.