The hard part is what might come next: Of those who receive antibiotics, between 10 and 25 percent develop long-term symptoms, such as fatigue, brain fog or dizziness. Scientists refer to these patients as “post-treatment Lyme disease” or “post-treatment Lyme disease syndrome,” also known as PTLDS. In 2020, nearly 2 million people were estimated to have PTLDS.
There are evidence-based treatments that can help. For example, medications in a class called neuromodulators, such as nortriptyline, can relieve the brain fog or pain often seen in PTS. But these treatments can take time to produce results and may involve some trial and error.
“The problem is that there is probably no single unifying mechanism — it may be a heterogeneous disorder,” said Paul Auwaerter, professor of medicine at Johns Hopkins University School of Medicine and former president of the Infectious Diseases Society of America. “It was devilishly difficult to understand.”
It is also important not to overlook any other important medical conditions that could explain your symptoms. Auwaerter, who has studied Lyme disease for two decades, said people have had delays in diagnosing cancer, ALS and other illnesses that had been misdiagnosed as Lyme disease.
At the same time, he said, doctors should think more about tick-borne illnesses and how they may be linked to symptoms years later. The key is to find a doctor with whom you can develop a long-term relationship.
“It’s really important to find someone who takes the time, starts from scratch, does a thorough history and examination and reviews your past tests,” Auwaerter said. “Then, over a series of visits, you work together to find the best diagnosis that can guide care.”
What do we really know about Lyme disease?
We have learned a lot about Lyme disease over the past five years.
We know that in cases of untreated Lyme disease, the bacteria can spread to other parts of the body, causing complications like carditis or arthritis. But if the disease is treated, the bacteria usually does. not escape antibiotics. For example, in a study of 252 patients, antibiotics did not work in only two patients, or 0.8 percent; in another study of 225 patients, antibiotics worked in all cases.
But in some patients, scientists now suspect an autoimmune reaction triggered by the initial infection. (Illnesses like inflammatory bowel disease or multiple sclerosis can also be triggered by infection.)
In other patients, the inflammation triggered by this initial infection, even if cleared, never fully subsides – perhaps because of the antigens left behind by the bacteria.
Recent studies have shown that PTLDS patients have elevated levels of certain autoantibodies and inflammatory mediators. Patients who had high levels of these markers after antibiotic treatment had a 12-fold increased risk of developing PTS.
PTLDS can also be associated with other conditions, including postural orthostatic tachycardia syndrome (POTS), which causes your heart to beat faster than normal when you go from sitting to lying down.
We have by no means fully understood PTS, but we are getting closer to improving our approach to prevention and treatment. I am optimistic about the Phase 2 results of a new three-dose Lyme disease vaccine, recently published in the Lancet Infectious Diseases. The phase 2 study found that the vaccine was safe, had few side effects and was effective in helping the body create antibodies against the bacteria. Phase 3 clinical trials are underway and Auwaerter, who is helping lead the trial, expects those results to be available by 2025 or 2026.
Other researchers are building biorepositories of patients infected with Lyme disease, tracking blood and urine over time to help understand the mechanisms by which some people develop long-term consequences.
Why is Lyme disease so controversial?
In the past, the poorly defined constellation of symptoms long after infection was called “chronic Lyme disease.” But the Centers for Disease Control and Prevention and others now recommend against using the term. Previous pushback against the name was based on its definition: a persistent microbial infection after antibiotics – which experts claimed did not exist. This morphed into the idea that the symptoms “didn’t exist” either – and that’s where, in the history of medicine, things went wrong.
We’ve seen a similar pattern in the history of long covid – or, before the pandemic, the Epstein-Barr virus – as validated research races to catch up with what patients are feeling. And as in these other cases, people suffering from PTLDS have long been stigmatized.
So let’s remember this: we can debate the cause of a disease and need more research to understand it – after all, that’s the very basis of good science. But someone’s suffering cannot be imagined.
What treatments don’t work for Lyme disease?
We have sufficient evidence on many therapies that not work for PTLDS. For example, repeated courses of antibiotics are no better than a placebo, an important lesson learned from several randomized controlled trials. These data did not surprise many in the medical community, as none of these trials found evidence of residual infection.
Auwaerter also warned against alternative therapies that can be potentially harmful, such as hyperbaric oxygen, chelation or coffee enemas.
What I want my patients to know
Lyme disease cases continue to increase with climate change and are expanding geographically. Recent studies estimate that approximately half a million people in the United States are diagnosed and treated each year. This figure doesn’t account for people who don’t receive treatment — and treatment delays are common, especially among Black patients and people of color who don’t always have a stereotypical rash.