[ed note: Doc Gumshoe is our favorite medical writer, and he usually pops in to explore a topic or answer questions readers have posed a couple times a month — he’s not a medical doctor and, as always, his opinions are his own.]
Let’s start this off with a hypothetical case, or rather, three hypothetical cases: three sisters – Maxine, Patty, and LaVerne – go for a lovely walk in the woods on a fine summer day. These young women are not dedicated hikers. They do not wear long pants tucked into their socks, they do not wear boots, they do not spray themselves with insect repellent. On the contrary, they wear nifty short shorts, sleeveless blouses, and cute open-toed sandals. They look like jazz babes, and they have a terrific time.
About a week later, Maxine starts to feel a bit strange. She’s unusually tired. She has chills and a headache. She’s surprised to find that she’s running a temperature – about 102°, in fact. She thinks she’s picked up some kind of a virus, and she figures that she’ll likely develop some other symptoms pretty soon.
After a couple of days, she feels worse – genuinely lousy – but no other symptoms have appeared. Her sisters urge her to get herself to the doctor, and she does so.
Her doctor looks her over, and in the course of the physical examination, he notices several round reddish rashes on her upper legs and lower back. They are over an inch wide and show no signs of a bite. There are small reddish areas in centers of the rashes, surrounded by a lighter area, and then darker slightly raised red ring at the edges, making the rashes look like bull’s eyes.
The doctor tells Maxine that she almost certainly has Lyme disease. She was bitten by a tick when she went for that nice walk in the woods, and the tick – Ixodes scapularis, also called a deer tick or a black-legged tick – infected her with a micro-organism, a spirochete called Borrelia burgdorferi. He explains that spirochetes are nasty little creatures, hard to eradicate, because they tend to travel far from the site where they enter the body and hide deep in the tissues where the antibiotics that are used to kill them don’t easily penetrate. A particularly dangerous spirochete is Treponema pallidum, the pathogen that causes syphilis, which – if not properly treated early on – can penetrate the tissues and cause dementia, cardiac damage, and liver damage many, many years after the initial infection. The Lyme pathogen is thought by some to have the same potential. That’s why early, aggressive treatment is crucial. A four week treatment with any of several oral antibiotics eliminates the Lyme pathogen most of the time.
The doctor does not do any further testing. Maxine’s symptoms and her bull’s-eye rashes are enough to diagnose Lyme disease, and, in any case, the blood tests for Lyme depend on the formation to antibodies to the pathogen, and antibodies wouldn’t yet have formed. There’s no reason to delay treatment pending confirmation by a blood test, and every reason to start treatment right away, to kill those evil little pathogens before they further conceal themselves.
Maxine’s bull’s-eye rashes – known as erythema migrans – are not the sites of the tick bite, by the way. The tick probably landed on Maxine’s leg as she brushed against a bush on her walk. Then it wandered over her body until it found a nice spot to dig in, which might have taken a full day or even longer. Then the tick buried itself in Maxine’s tender flesh, feasted on her blood, and dropped off when it had had enough. Maxine would likely have felt nothing when the tick bit her – tick bites don’t sting or itch. As her doctor explained, if Maxine had felt the tick bite, she would have likely brushed the tick away, and the tick would have gotten no free lunch. Ticks are not quick, like mosquitoes, which can get their blood meal in a few seconds before you swat them.
Maxine’s doctor prescribes a 28-day course of a common antibiotic, probably doxycyc