Lyme disease diagnosis and treatment
So if you’re unlucky enough to have been bitten by a tick infected with Lyme Disease, what should you look out for, and how should you be treated? Moreover, what can happen if you miss the initial diagnosis? John Aucot specialises in Lyme Disease at Johns Hopkins School of Medicine...
John - Acute Lyme disease starts at the site of a tick bite. When that bacteria is inoculated into the skin, acute Lyme disease usually begins a week or two later. And that local infection typically causes redness around the side of the tick bite and that redness expands over time as the bacteria multiply with the infection. And then over a period of a week or two causes a round, red skin lesion. And that's where the infection starts, and then if it's not treated initially, that infection has the potential, really in more than half the cases, to enter the bloodstream and spread to other areas of the body and where it spreads to is typically other areas of the skin. So you can get multiple skin lesions from spread. It can spread to the heart and cause inflammation of the heart and especially the electrical system of the heart. And it can spread to the nervous system, the lining around the brain called the meninges and cause meningitis. It's especially prone to go to the cranial nerves, especially this one nerve that causes facial palsy, causes one side of the face to droop, and it can go to the peripheral nerves and to the joints. And so those diverse symptoms in that early what we call 'disseminated' phase as the bacteria spreads to other parts of the body, can cause a diversity of symptoms and make it actually somewhat difficult to diagnose if you don't recognise that initial round, red skin lesion at the side of the tick bite.
Eva - And what is the treatment, if you notice that you've got a rash, what treatment would a doctor give you?
John - So that's the good news is the treatment's pretty straightforward. Treatment of early Lyme disease is with a pill antibiotic. It's typically doxycycline. It's very effective at treating the Borrelia bacteria that causes Lyme disease, especially when administered in that first couple of weeks. And then you take the oral pill antibiotic for several weeks. And that's generally curative.
Eva - So essentially if you take the antibiotic quickly enough, then you're probably not going to have any lasting effects from having had Lyme disease.
John - Odds are that early treatment prevents later manifestations. It's very, very good at preventing later neurologic or joint disease. There is however, an important subset of people that even with early antibiotics still have lingering symptoms, especially symptoms like fatigue and achiness and memory issues. We have a cohort study where we start following people at the very first moment of infection when they have the rash. And we treat the people obviously with a standard of care doxycycline and then follow them over time. And then when you do that prospectively over time, you see it in our states, about 15% of the people clinically still have fatigue and other symptoms, six months after their treatment.
Eva - How do you know if that's you still have Lyme disease or if that's your body being affected by the fact of having had Lyme disease, because there are some things like post viral fatigue, for example, that can last for a long time.
John - That's the holy grail in the research field in Lyme disease; what causes these persistent symptoms? With the onset of COVID actually, we've seen an example of a virus. Now, Lyme disease is a bacteria, but we see in COVID that viruses can cause long lasting symptoms even after the virus is apparently out of the system. So the tough question that remains unresolved is "What is the mechanism of these persistent symptoms after antibiotic treatment of Lyme disease?" And there's a range of hypotheses. There may be lingering bacteria hidden away in the tissues. There may be bacterial products, proteins, or nucleic acid fragments in the tissues that trigger ongoing inflammation, or the bacteria and its products may be gone and the immune system has taken on its own auto-immune activity where the immune system, instead of being our friend, becomes our enemy in a way. And what we've been able to show from our studies is that, using the blood from these patients that go on to develop a persistent illnesses, there are changes in their immune system, in their metabolism. And so those immune markers are potential future tests. For instance, we have one immune marker that's a chemokine. It's a protein that attracts immune cells into tissues, and that chemokine CCL 19 remains elevated after treatment in the people that are destined to go on to have persistent symptoms.
Eva - And what can we do to help people who are suffering from persistent symptoms.
John - So I think this is where we've fallen short is helping our patients with persistent symptoms in Lyme disease. The first reason is it still remains a contested illness. There's many contested illnesses and they're predominantly ones characterised by lots of patients' symptoms and a paucity of objective biologic markers on blood tests or imaging. And so the first way I think we can help the patients is recognising that these are real illnesses, that it's not the patient's fault there's illnesses isn't all in their head. It's not just because they're depressed or anxious. And then the second step is, even without specific proof of the mechanism, offering the patient hope and care. Treat their symptoms. We can help them cope with their symptoms. We can help encourage them to have healthy behaviours. And in the same time also try to treat the illness as best we can with the knowledge that we have at this point. And then finally, I think to give patients hope that we're working on this, that we're trying to do research to understand the mechanisms because understanding the mechanism of the illness is obviously the key to designing future therapies.