Why Lyme Disease Is Sometimes Missed: Insights from a GP Pilot Study
Lyme disease can be difficult to recognize.
Symptoms vary, and early testing has limitations.
Diagnostic uncertainty may contribute to missed cases.
Why is Lyme disease sometimes missed? Lyme disease can be overlooked because its symptoms often resemble those of other illnesses, early laboratory tests may be negative, and not every patient recalls a tick bite or develops the classic erythema migrans (EM) rash. A pilot study published in BJGP Open examined how general practitioners (GPs) evaluated a series of Lyme disease case scenarios and identified several factors that contributed to diagnostic uncertainty and delayed recognition.
The study focused on how physicians selected diagnostic codes within electronic health records, using Lyme disease as an example of a condition with varied and sometimes non-specific presentations. Investigators presented GPs with 11 simulated clinical cases representing dermatologic, neurologic, cardiac, and rheumatologic manifestations of Lyme disease and then assessed both their differential diagnoses and the diagnostic codes they selected.
The investigators found that Lyme disease appeared on the physicians’ differential diagnosis list in only 5 of the 11 cases, yet only 2 cases were ultimately assigned a Lyme disease-specific Read code, writes Tulloch.
Importantly, the authors emphasized that clinical suspicion and diagnostic coding were not always the same. Some physicians considered Lyme disease among their possible diagnoses but chose a more general diagnostic code while awaiting additional clinical information or laboratory confirmation.
Pilot study examined Lyme disease diagnostic and coding decisions
The Lyme disease case presentations varied widely, illustrating why the illness can be challenging to recognize when patients do not present with classic early findings.
- Classic erythema migrans (EM) rash
- Borrelial lymphocytoma of the ear lobe
- Acrodermatitis chronica atrophicans (ACA) with peripheral neuropathy
- Bell’s palsy following an “insect bite”
- Recurrent synovitis of the knees
- Multiple erythema migrans rashes after walking in Dartmoor
- Heart rhythm abnormalities
- Fatigue, post-exertional malaise, anxiety, headaches, and memory problems with a positive Lyme disease test from an international laboratory
- Fatigue, arthralgia, poor concentration, myalgia, and mood swings
- A non-engorged tick attached to the scalp
- Poor fine motor movements and a rash occurring two months earlier at scout camp. (This patient had not been treated with erythromycin.)
Diagnostic uncertainty influenced coding decisions
The physicians described several factors that contributed to diagnostic uncertainty and reduced their willingness to assign a specific Lyme disease Read code, particularly when laboratory confirmation or a clear history of tick exposure was lacking.
- “If I can’t diagnose, I will pick the main symptom to code. I will always do this unless I’m almost [100%] positive of the diagnosis. Sometimes, if I’m really not sure, I will write everything in free text and not code anything.”
- “Lyme disease is a possibility here. But I wouldn’t leap to it without a history of a tick bite.”
- “I would never write Lyme disease on a patient’s record until I had a positive lab diagnosis. I’m wary because of potential litigation, and I don’t want to cause problems for future doctors treating that patient.”
- “I won’t code Lyme disease until they’d seen an NHS specialist. I’d be very suspicious if it [laboratory results] was a ‘high street’ or ‘internet’ lab, so I would arrange serology to be sent to a local lab.”
Several physicians indicated they preferred to wait for additional clinical evidence, laboratory confirmation, or specialist evaluation before assigning a Lyme disease-specific Read code. Others explained that the absence of a reported tick bite lowered their clinical suspicion, despite the varied presentations shown in the case scenarios.
The authors emphasized that diagnostic coding and clinical suspicion are not always the same. A physician may consider Lyme disease in the differential diagnosis yet choose to code the patient’s primary symptom—such as rash, fatigue, or Bell’s palsy—rather than Lyme disease until sufficient evidence supports a definitive diagnosis.
The findings illustrate several well-recognized diagnostic challenges. Early Lyme disease may present with non-specific symptoms, laboratory testing can be negative during the first few weeks of infection, and many patients do not recall a tick bite. Together, these factors may contribute to delayed recognition in some cases. Learn more about why early Lyme disease tests can be negative and the limitations of laboratory testing.
Previous experience improved recognition of Lyme disease
Some physicians were more comfortable recognizing Lyme disease because of their previous clinical or personal experience.
- “This is a tick; I’ve been bitten many times before.”
- “I had a patient diagnosed in the last couple of months; a child with non-specific knee pain. We initially suspected an infected knee joint. He’s now been successfully treated and has been fine since.”
- “There are so few Lyme disease specialists across the country. A friend of mine has Lyme, so I know the difficulties.”
Previous experience with Lyme disease appeared to increase physicians’ confidence in recognizing less typical presentations. In contrast, clinicians with less experience were generally more likely to seek additional evidence before assigning a Lyme disease diagnosis or selecting a Lyme disease-specific diagnostic code.
The study enrolled only eight general practitioners and relied on simulated case reviews rather than actual patient encounters. Several physicians were also unable to complete every case because of time constraints, limiting the conclusions that can be drawn from the findings.
Although small, the study highlights issues that extend beyond this pilot project. Lyme disease can present with dermatologic, neurologic, cardiac, rheumatologic, or constitutional symptoms, making diagnosis challenging when patients do not have a classic erythema migrans rash or remember a tick bite. These findings reinforce why Lyme disease is sometimes misdiagnosed in clinical practice.
The authors also noted an important exception. Patients with a classic erythema migrans rash should generally be diagnosed clinically without waiting for laboratory confirmation because early serologic testing may be negative. Delaying treatment while awaiting test results may allow the disease to progress to more advanced manifestations.
Clinicians should evaluate the patient’s exposure history, physical examination, and overall clinical presentation together with laboratory testing when appropriate. Recognizing the broad spectrum of Lyme disease symptoms may help reduce delayed or missed diagnoses.
Editor’s note
This pilot study involved only eight general practitioners and used standardized case scenarios rather than actual patient encounters. Its primary focus was physician coding behavior rather than the overall accuracy of Lyme disease diagnosis. Nevertheless, the findings illustrate how diagnostic uncertainty, variable clinical presentations, limitations of early laboratory testing, and the absence of a recalled tick bite may influence both diagnostic thinking and coding decisions. Larger studies evaluating real-world clinical practice would help determine how often these factors contribute to delayed recognition of Lyme disease.
Frequently Asked Questions
Why is Lyme disease sometimes missed?
Lyme disease may be overlooked because its symptoms overlap with many other conditions, early antibody tests can be negative, and many patients do not remember a tick bite or develop the classic erythema migrans rash. The pilot study also found that diagnostic uncertainty influenced how some physicians selected diagnostic codes for patients with possible Lyme disease.
Why don’t some doctors want to test for Lyme disease?
Doctors may decide against Lyme disease testing when they believe a patient’s symptoms or exposure history make infection unlikely. They may also be concerned that testing patients with nonspecific symptoms will produce false-positive or difficult-to-interpret results. In other cases, physicians may underestimate geographic exposure, overlook travel history, rely too heavily on a remembered tick bite or rash, or be unfamiliar with the limitations of early testing. A classic erythema migrans rash can be diagnosed clinically without waiting for a blood test.
Can Lyme disease be diagnosed without a positive blood test?
Yes. Patients with a classic erythema migrans rash can be diagnosed clinically without waiting for laboratory confirmation because antibody tests may be negative early in the illness. In patients without a characteristic rash, clinicians consider the history, physical examination, exposure risk, and appropriate laboratory testing together.
Does everyone with Lyme disease remember a tick bite?
No. Many patients never notice a tick bite because immature ticks are extremely small and their bites are often painless. The absence of a recalled tick bite should not exclude Lyme disease when the clinical presentation is otherwise consistent.
Clinical Takeaway
This pilot study suggests that Lyme disease may sometimes be missed because of diagnostic uncertainty, varied clinical presentations, and the challenges of assigning a definitive diagnostic code when clinical evidence is incomplete. Although the study evaluated physician coding behavior rather than diagnostic accuracy itself, it highlights factors that may contribute to delayed recognition of Lyme disease in primary care.
Maintaining Lyme disease in the differential diagnosis, particularly in patients with compatible symptoms and possible tick exposure, and recognizing that early Lyme disease may be diagnosed clinically before laboratory confirmation, may help reduce delayed diagnosis and treatment.
Related Articles
Why Early Lyme Disease Tests Can Be Negative
References
- Tulloch JSP, Beadsworth MBJ, Vivancos R, Radford AD, Warner JC, Christley RM. GP coding behaviour for non-specific clinical presentations: a pilot study. BJGP Open. 2020;4(3):bjgpopen20X101050.
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 have had the medicine for Lyme disease three times. Each time it made a tick bite that was getting progressively ugly vanish.
I have had to stop going into the woods in back of my house.
The third time it was not my doctor but some clinic and I had to talk the doc into prescribing, then he wanted to prescribe one pill instead of the standard regimen, I had to explain how the disease hides by partly going dormant.
I am lucky I heard and read a lot about this disease before I had my problems, my sister has it, in later stages you can’t get rid of it.
I am sorry you and your sister are having such difficulties.
My sister also has Lyme disease and Dr’s in Nebraska don’t (at least a few years back) treat that here- they don’t believe it exists.
I, after taking immunizations for a gov job and going hiking in the mountains soon after, was then bit by something. A mostly red circular rash around it, white smaller interior. Maybe a 1 1/2 inch diameter.
A couple of months after the bite, that I presume was a tick- the thing was attached to me- I thought it was mud and pulled it off. However, my legs started to feel heavy and I felt as if I was dragging them along. I went to see my internal med Dr, who refused to give my a Lyme test. He said they don’t believe Lyme is in Nebraska. My sister got hers by the stream in her back yard, but I got mine in Colorado. He still wouldn’t listen to me. He refused to take any lab.
Now, my sis heard of it and said she insisted he provide the lab work. He refused, citing “it’s political “. I don’t know what that means, and he wasn’t telling me more.
The symptoms continued, I started having major cramps in my muscles, sometimes for hours (still true today-still no dx) and vomiting spells. That had never happened to me before. My sis had to go to Missouri for a dx and tx for years.
My sis went out and purchased the test kit and told me to take it to the lab, which I did- had the physician give it to them and prescribe it. He said the nurse would call w results when they came in. 3 weeks later, still no call, so I called the office. They said they lost it. No offer to retake or to refund fir the cost of it. It’s political alright- in their office.
I was studying nutrition so did a deep dive in foods that can heal the body. It took about 2.5 years to be able to walk freely, but theweakness and fatigue never went away.
I fell a couple times, torn muscles around my knee, finally agreed to a cortisone injection in my knee a year later, as no Dr would treat (I guess) bc I was uninsured.
I never realized the heart rhythm disturbances could be from Lyme. Mine came a couple years after the bite. Anxiety was out of this workd- I don’t usually suffer from that. Also, I was working and going to school, nearly full time each and driving 2.5 hrs 5 days a week. Crazy busy, trying to get help but nobody would.
Went back to Dr saying I really needed some help. He didn’t even look at me, he was mire interested in clearing pics off my phone so he could install an app and told ne to walk more. He wasn’t lustening- I couldn’t! But I wanted to.
Fast forward a couple years…I was working at my new FT job in Hospital and LTC when covid began. It got crazy fast. Staff left, Mgr left, I, as assist to Mgr, had to work 60-80hrs a week, a lot on my feet.
Progressively, the severe body pains set in, my legs developed such terrible cramps in my legs that I couldn’t get out of bed- terribly painful! I had to call my son to bring me a cane so I could use the bathroom. 2 days later, the next one froze up also.
I had gone to ED for the first, w no resolution except a possible infection in the veins, but while he said he should prescribe something for that, he only prescribed zorelto. I’m glad I questioned the 1,000 dollar med. I had paid for a week’s worth and went back to ask the nurse who was also attending that eve what she thought. She asked if a clot was dx. No, it wasn’t. She said she woukd advise against it.
As I waited the 30 days behind schedule my own dr had, I literally stood up from my sofa, lost my balance, tried to correct on one side and twisted my ankle all the way around- trimalleolar fx .
2.5 years fast forward…I still have significant pain and swelling in the joint. Bone pain (had an x-fix), metal plates which I seemed to be allergic to, so they were removed, some screws removed and the bone shaved down.
The crazy covid days didn’t help, but I believe my legs were still impacted by the stinking bite that nobody woukd treat. Still, I get terrible, terrible leg cramps. Why do they not take it seriously?
I reported various Lyme symptoms to 7 doctors spanning 5 years. Two used inferior (unethical tests, I believe) to rule out Lyme. I finally paid, out of pocket, $600 to Vibrant Labs (my blood was drawn by my local doctor and sent to their lab) and $400 doctor fee for interpretation (a total of $1000)! The results showed high zonulin, markers for a chronic inflammatory condition which I was diagnosed with, the crossing of the blood brain barrier and many additional problems. The test showed 14 tick borne pathogens identified as severe or moderate and 42 tickbourne pathogens rated as under control. Interestingly, many of the 42 “controlled” pathogens were in the 8 or 9 range where 10 indicates as problematic and indicative of Lyme disease. I also have a raging E Barr infection, numerous mycotoxins and various resistant pneumonias. After taking antibiotics for 5 months, I now have leaky gut, also proven by the test. All this and I do not meet the CDC criteria for Lyme which is SHAMEFUL! I do meet the alternative Lyme criteria. I have been housebound since July 2021 with excruciating bodily pain and severe fatigue. I have 0 quality of life. I contacted every Communicable Disease Doctor I could find in St. Petersburg, FL and I was REFUSED TREATMENT even when I asked to be seen for the pneumonias and mycotoxins. I do not know how these doctors can legally refuse me treatment. Lyme patients are scorned, told they are liars through action by some doctors, ignored, and DENIED TREATMENT by mainstream medical establishment. I now have an invoice for $17,563 + for upcoming Lyme treatment that mainstream medical refuses to assist with. Naturally, I have had to refuse much of the medical treatment that my Lyme specialist has recommended for me. I will attempt to limit my bill to $10,000 which I still cannot afford! This is a horrific injustice to all Lyme patients.