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Lemons and Lyme: Bogus tests and dangerous treatments of the Lyme-literati

Tick

It’s that time of year when every day I can expect to see at least one patient with a concern about Lyme disease. In Lyme-endemic regions such as Western Massachusetts, where I practice pediatrics, summer brings a steady stream of children to my office with either the classic Lyme rash (erythema chronicum migrans, or ECM), an embedded tick, a history of a tick bite, or non-specific signs or symptoms that may or may not be due to Lyme disease. Sometimes the diagnosis is relatively straightforward. A child is brought in after a parent has pulled off an engorged deer tick, and there is a classic, enlarging ECM rash at the site of the bite. More often the presentation is less clear, requiring detective work and science-based reasoning to make an informed decision and a diagnostic and therapeutic plan based on the best available evidence. Depending on the story, the plan may include immediate treatment without any testing (as in the straightforward case described above), immediate testing without treatment pending test results, or waiting as we watch and see how a rash progresses before doing anything. An example of this latter course of action would be when a patient comes in with a pink swelling at the site of a new tick bite. In this case, it may not be clear if the swelling is a Lyme rash or simply a local reaction to the bite, a much more common occurrence. The classic ECM rash (an enlarging, red, circular, bull’s-eye rash at or near a tick bite) typically develops 1-2 weeks after a tick bite, but can occur anywhere from 3-30 days later. It then expands and darkens over another 1-3 weeks before fading. This classic rash is not the most common rash of Lyme disease, however, as it occurs in only about 30% of cases. Instead, the rash may be uniformly pink or red (or even darker in the center) without the target-like appearance, or may be a linear rash, expanding outward from the tick bite site. In the case of a patient who comes in with a vague, pink swelling within a day few days of a tick bite, we will typically wait and see what happens to the rash. If it is a local reaction, it will likely resolve within another few days. With Lyme disease, the rash will continue to enlarge and declare itself as an ECM rash. Another unclear and not uncommon situation is when a patient comes in with non-specific symptoms such as fatigue, musculoskeletal pains, and headache. If warranted by the history and the physical exam, we may in this case order Lyme testing. This may not give us an answer even if the patient has Lyme disease, because results are often negative in the first few weeks of the disease. In this case, if symptoms persist or evolve, we will repeat the testing in another few weeks at which point true Lyme disease will test positive and can then be treated. The good news is that the treatment of Lyme disease, particularly in the early, localized phase of the disease, is extremely safe and effective with a 14-day course of antibiotics. The testing is also relatively straightforward, with very good sensitivity and specificity when performed correctly. And this is where the bad news comes… (more…)

Posted in: Diagnostic tests & procedures, Science and Medicine

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Why Doctors Order Too Many Tests

While cleaning out some old files, I was delighted to find an article I had clipped and saved 35 years ago: a “Sounding Boards” article from the January 25, 1979 issue of The New England Journal of Medicine. It was written by Joseph E. Hardison, MD, from the Emory University School of Medicine; it addresses the reasons doctors order unnecessary tests, and its title is “To Be Complete.” Today we have many more tests that can be ordered inappropriately and the article is even more pertinent and deserves to be re-cycled. He says,

When challenged and asked to defend their reasons for ordering or performing unnecessary tests and procedures, the reasons given usually fall under one of the following excuses…

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Posted in: Diagnostic tests & procedures

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