Lyme Disease: An Underdiagnosed Cause of Mono-Arthritis?
Lyme disease may present as mono-arthritis.
Persistent knee effusion and synovitis can be missed clues.
This Inside Lyme case highlights delayed recognition of Lyme arthritis.
Welcome to another Inside Lyme Podcast with your host Dr. Daniel Cameron. In this episode, Dr. Cameron discusses the case of a 26-year-old man whose clinical evaluation overlooked Lyme disease as a cause of mono-arthritis and persistent knee pain.
The case was described by Marcelis and colleagues in a paper entitled “Lyme Disease: A Probably Underdiagnosed Cause of Mono-Arthritis.”1
Mono-Arthritis and Lyme Disease
A 26-year-old man presented with acute knee pain. He recalled having similar knee pain occurring one year earlier when he began walking for extended periods of time.
A magnetic resonance imaging (MRI) study of the knee revealed a large joint effusion. He was not diagnosed or treated for Lyme disease.
Lyme mono-arthritis commonly affects a single large joint—most often the knee—and may present with swelling, synovitis, or recurrent joint effusion.
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Persistent Knee Effusion and Synovitis
Four months later, he had a follow-up MRI, which again showed persistent joint effusion with diffuse enhancement, thickening of the synovium, enlarged lymph nodes in the popliteal fossa, and enhancement of the soleus muscle.
He was subsequently evaluated again for acute knee pain that had been present for several days.
On further questioning, the 26-year-old man recalled a history of serologically confirmed Lyme disease.
“The combination of synovitis, lymphadenopathy in the popliteal fossa, and serology led to the diagnosis of Lyme mono-arthritis,” wrote the authors.
“Mono- and oligoarthritis is one of the most common manifestations [of Lyme disease], mostly affecting the knee, although the hip, ankle, elbow, and wrist may be affected.”
Lyme Arthritis vs Septic Arthritis
There was no evidence of septic arthritis.
The authors highlighted the importance of a careful clinical history to avoid overlooking Lyme disease in patients with unexplained mono-arthritis or recurrent knee effusion.
For more on delayed diagnosis, see Causes of treatment delays for Lyme disease.
Frequently Asked Questions
Can Lyme disease cause mono-arthritis?
Yes. Lyme disease may present as mono-arthritis, particularly involving the knee with swelling, synovitis, or joint effusion.
What is Lyme mono-arthritis?
Lyme mono-arthritis refers to inflammation affecting a single joint caused by Lyme disease. The knee is the most commonly involved joint.
Can Lyme arthritis be mistaken for septic arthritis?
Yes. Lyme arthritis may resemble septic arthritis or other inflammatory joint conditions, making careful history and evaluation important.
Why is timely treatment of Lyme disease important?
Delayed recognition of Lyme disease may increase the risk of persistent symptoms, recurrent inflammation, or prolonged joint complications.
Questions Addressed in This Podcast Episode
- What is synovitis?
- What is Lyme arthritis?
- What is septic arthritis?
- What manifestations of Lyme disease are there?
- Why is timely treatment of Lyme disease important?
- Could the treatment delay have been avoided?
- What are the therapeutic options?
Thanks for listening to another Inside Lyme Podcast. Please remember that the advice given is general and not intended as specific advice to any particular patient. If you require specific advice, please seek that advice from an experienced professional.
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References:
- Marcelis S, Vanhoenacker F. Lyme Disease: A Probably Underdiagnosed Cause of Mono-Arthritis. J Belg Soc Radiol. 2021;105(1):80. doi:10.5334/jbsr.2625
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 walked and hiked and had pain in my left knee first, followed by the right knee. Mri of left knee said I had pain but had a torn medial miniscus. I asked why it has pain In other knee and no answer for it. I could not walk well and had cortisone shot in November, now they are both painful again. Hopefully wil find an answer. Doctors say arthritis!
AnnMarie, you might want to check out articles on Dr. Saul’s website: http://www.doctoryourself.com/. He presents the work of Dr. William Kaufman who linked arthritis to vitamin B and C deficiencies and diet. I’ve found the niacinamide/vit. C protocol to help me significantly. While the underlying issue is probably Lyme/MSIDS infection or damage, there are things we can do to alleviate symptoms or halt the process. As always, make sure to discuss with your doctor.