Friday, June 07, 2013

Lyme disease misconceptions

Misconceptions about Lyme disease abound and have fueled politicized debates and a good deal of quackery. A recent piece in the green journal (free full text) provides some clarity and includes a list of bullet points about the misconceptions. Here are a few:

Myth:
“'Blood tests are unreliable with many negatives in patients who really have Lyme disease'”
Fact:
“Just as with all antibody-based testing, these are often negative very early before the antibody response develops (less than 4-6 weeks). They are rarely if ever negative in later disease.”


Myth:
“'Antibiotics make blood tests negative during treatment'”
Fact:
“There is no evidence that this happens and no biologic reason it would.”

Myth:
“'Lyme disease is a clinical diagnosis that should be made based on a list of symptoms'”
Fact:
“No clinical features, except erythema migrans or possibly bilateral facial nerve palsy—in the appropriate context—provide sufficient specificity or positive predictive value. Laboratory confirmation is essential except with erythema migrans.”

Myth:
“'B. burgdorferi infection is potentially lethal'”
Fact:
“Although Lyme disease can cause heart or brain abnormalities, there have been remarkably few—if any—deaths attributable to this infection”

Myth:
“'If, following treatment, symptoms persist, or serologic testing remains positive, additional treatment is required'”
Fact:
“Multiple well-performed studies demonstrate that recommended treatment courses cure this infection. Retreatment is necessary occasionally, but not frequently.”

Now as readers know I'm not a fan of the Institute of Medicine (IOM) but they are quoted in the article and I happen to agree with what they said:

...strong emotions, mistrust, and a game of blaming others who are not aligned with one's views” have resulted in a heated and politicized debate. A number of factors have contributed to this “debate”—perhaps not the least of which is a tension between the concept of evidence-based medicine and medicine's historical inductive approach from anecdotal observation. This tension is reflected in 2 frequently repeated, interrelated assertions—that laboratory testing for Lyme disease is unreliable and that the disease should be defined “clinically”—meaning syndromically.

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