Are doctors reluctant to diagnose Lyme disease?
A study by Tulloch and colleagues, published in the journal BJGP Open, examined the decision-making behavior of general practitioners (GPs) when applying Read codes to non-specific clinical presentations. The authors used Lyme disease as a case example and recruited GPs in the North West of England. 
Investigators asked clinicians to review 11 cases of Lyme disease. They found that only 5 cases contained Lyme disease on their differential diagnosis list, and only 2 cases were coded as Lyme disease, writes Tulloch.
The Lyme disease case presentations varied:
- 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 EM rashes after walking in Dartmoor
- Heart rhythm abnormalities
- Fatigue, post-exertional malaise, anxiety, headaches, and memory issues with a positive Lyme disease test from an international lab
- Fatigue, arthralgia, poor ability to concentrate, myalgia, mood swings
- Non-engorged tick attached to scalp
- Poor fine motor movements and a rash occurring 2 months previously at scout camp. (This patient had not been treated with erythromycin.)
The physicians cite several reasons for their reluctance in considering Lyme disease as a diagnosis.
- “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.”
Some doctors were more familiar with Lyme disease through their own experiences.
- “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.”
The study, which enrolled only 8 general practitioners, involved case reviews rather than actual cases. Some of the doctors were unable to complete their case evaluation due to time constraints.
Editor’s note: Their results should encourage future researchers to look for any reluctance to diagnose Lyme disease in actual practice.
- Tulloch JS, Beadsworth MB, Vivancos R, Radford AD, Warner JC, Christley RM. GP coding behaviour for non-specific clinical presentations: a pilot study. BJGP Open. 2020.