Anchoring Bias Lyme Disease: When Diagnosis Goes Wrong
Anchoring bias in Lyme disease can occur when clinicians fixate on an initial diagnosis and fail to adjust their thinking as new information emerges.
Conversely, this same cognitive bias may also occur when Lyme disease is incorrectly diagnosed and the true underlying illness is missed.
Aguirre and colleagues describe such a scenario in their paper,
Anchoring Bias, Lyme Disease, and the Diagnosis Conundrum.
Case Report: Suspected Lyme Disease
A 29-year-old man living in Florida presented with severe headaches, fever, myalgia, and diarrhea. He developed facial paresis with nonfocal paresthesia, bilateral scotomas, and a self-resolved erythematous patch along his inner thigh weeks prior.
“Initial suspicion for early disseminated Lyme with aseptic meningitis was fueled by tick exposure, cutaneous exanthem, and facial palsy,” writes Aguirre.
Laboratory testing revealed a positive IgM Western blot and a negative IgG for Borrelia burgdorferi. Based on these findings, clinicians initially diagnosed early disseminated Lyme meningitis and prescribed doxycycline.
Diagnostic Reassessment and Final Diagnosis
After additional testing, the diagnosis was revised. The patient was ultimately found to have Echovirus 30 and Coxsackie B5 infection.
The authors concluded that the initial diagnosis of Lyme disease represented an example of anchoring bias.
“His headache and vision improved gradually,” writes Aguirre. “However, the patient experienced distress from misdiagnosis with a life-threatening and contagious illness.”
Clinical Perspective on Anchoring Bias and Lyme Disease
Editor’s note:
I am not convinced that this case represents a clear example of anchoring bias. Lyme disease does occur in Florida.
“Of 216 regional cases reported in 2016, 132 were confirmed positive by the CDC,” writes Aguirre.
I also disagree with the authors’ suggestion that anchoring bias could have been avoided through strict adherence to the CDC two-tier testing algorithm. Only 25% of patients with early Lyme disease test positive using two-tier testing.
It is common and appropriate medical practice to treat suspected infections empirically while awaiting test results. It is equally appropriate to revise a diagnosis as new clinical or laboratory information becomes available.
This case highlights the complexity of diagnosing Lyme disease diagnosis and the risk of labeling thoughtful clinical decision-making as anchoring bias in conditions where diagnostic certainty is inherently limited.
It also reinforces the importance of recognizing Lyme disease misconceptions that can influence both overdiagnosis and underdiagnosis.
Related Articles:
Relying on a negative Lyme disease test can prove deadly
Study finds misdiagnosis and delayed diagnosis common for Lyme disease patients
References:
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Aguirre LE, et al.
Anchoring Bias, Lyme Disease, and the Diagnosis Conundrum.
Cureus. 2019;11(3):e4300.
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 was very I’ll in march 2016 I thought it was a bad cold, but it did not go away after two weeks. I had a fever, swollen lymph nodes, muscle and joint aches, and cfs, and chills, and chest pain. It took 2 years before doctors figured it out.
In 2002 I lived in Northern Baltimore County, Maryland. I walked our dog to a small stream daily. One morning while in the shower I saw a large bullseye. Called my Doctor who was a neighbor and friend. Went in immediatly, blood was taken, shot of antibiotics, pills for 1 month
I had a severe headache, joint pain, flu symptoms. Needed pills for another 6 weeks.
I needed another 6 weeks of antibiotics which seemed to do the trick for awhile.
Now I live in Mobile Alabama the joint pain is back (is it old age 79?) sporatic headaches again. Yadda, yadda, yadda.
Always uncertainty.