Could Knee Monoarthritis Be Lyme Arthritis? A Case Report
Knee monoarthritis may be caused by Lyme disease
Recurrent joint effusions can delay diagnosis
Early recognition may prevent prolonged symptoms
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 knee monoarthritis was ultimately diagnosed as Lyme arthritis after the possibility of Lyme disease was initially overlooked.
Could knee monoarthritis be Lyme arthritis? This case report describes a 26-year-old man with recurrent knee pain and joint effusions whose diagnosis of Lyme arthritis was initially missed. The case highlights how Lyme disease can present as isolated knee monoarthritis and why a careful clinical history is important.
The case was described by Marcelis and colleagues in a paper entitled “Lyme disease: A probably underdiagnosed cause of Mono-arthritis.”1
A 26-year-old man presented with acute knee pain and knee monoarthritis. He recalled having similar knee symptoms one year earlier when he began walking for extended periods of time.
A magnetic resonance imaging (MRI) of the knee revealed a large joint effusion. He was not diagnosed or treated for Lyme disease.
Recurrent knee effusions are a common presentation of Lyme arthritis and may be mistaken for other orthopedic or inflammatory conditions.
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Four months later, he had a follow-up MRI, which again showed a persistent joint effusion with diffuse enhancement, thickening of the synovium, enlarged lymph nodes in the popliteal fossa, and enhancement of the soleus muscle.
Delayed Diagnosis of Lyme Arthritis
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.
The case illustrates how Lyme arthritis may present as isolated knee monoarthritis without other obvious manifestations of Lyme disease.
Lyme Arthritis Is a Common Cause of Knee Monoarthritis
“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.”
There was no evidence of septic arthritis. The authors highlighted the need for a careful clinical history to avoid overlooking Lyme disease.
Learn more about Lyme arthritis, common Lyme disease symptoms, and the causes of treatment delays for Lyme disease.
The Following Questions Are 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?
Frequently Asked Questions
Can Lyme disease cause monoarthritis?
Yes. Lyme disease commonly causes monoarthritis, particularly involving the knee. Patients may develop swelling, pain, and recurrent joint effusions.
What is Lyme arthritis?
Lyme arthritis is a late manifestation of Lyme disease characterized by inflammation of one or more joints, most often the knee.
Can Lyme disease cause recurrent knee swelling?
Yes. Lyme arthritis commonly affects the knee and may cause recurrent swelling, joint effusions, stiffness, and limited range of motion.
Can Lyme arthritis be mistaken for septic arthritis?
Yes. Lyme arthritis can present with a swollen painful knee and may initially be confused with septic arthritis or other causes of monoarthritis.
Clinical Takeaway
Lyme arthritis should be considered in patients with unexplained knee monoarthritis, recurrent joint effusions, or persistent synovitis, particularly in endemic regions.
A careful history that includes prior tick exposure and previous Lyme disease can help clinicians recognize this common but sometimes overlooked presentation.
This case demonstrates that Lyme arthritis may present as isolated knee monoarthritis and can be missed when Lyme disease is not included in the differential diagnosis.
Related Articles
Successful treatment of Lyme arthritis after knee surgery
Preventing unnecessary surgery for children with Lyme arthritis
Diagnosing Lyme arthritis of the hip in children
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.