For all of you with strong opinions and relevant experiences regarding Lyme disease, the public comment period on the 2019 Draft Guidelines for the Prevention, Diagnosis and Treatment of Lyme Disease has been extended until Sept. 9.
The guidelines are not final yet — that’s the whole point of a public comment period — but they represent consideration, consensus and compromise by a wide variety of specialists looking at data on an infection which everyone understands is often frustrating for patients and for doctors as well, and which continues to be a source of public anxiety.
The guidelines were developed after a great deal of discussion and literature review by experts from the Infectious Diseases Society of America, the American Academy of Neurology and the American College of Rheumatology, as well as people from other specialties, notably cardiology and pediatrics.
I asked Dr. H. Cody Meissner, who is professor of pediatrics and director of pediatric infectious disease at Tufts, to talk about some of the issues that are particularly relevant to children with Lyme, and about the process of working on the guidelines, for which he represented the American Academy of Pediatrics. Bearing in mind, always, that the guidelines as they stand are not finalized, he pointed particularly to a change in the antibiotics recommendations for children.
The recommendation used to be that doctors should not prescribe doxycycline for children under 8 years old, because of worry that this class of antibiotics might lead to tooth enamel damage and discoloration. While that can happen with tetracycline, a related antibiotic, Dr. Meissner said, the available evidence shows that doxycycline itself doesn’t do that.
One advantage of treating some cases of Lyme with doxycycline, rather than the amoxicillin that used to be the antibiotic recommended for young children, is that doxycycline is effective against ehrlichiosis, another tick-borne disease, which can occur together with Lyme, transmitted by the same tick.
Doxycycline can also be used in children who seem to have neurological manifestations of Lyme, especially facial nerve palsy. “Most of those children don’t need to be admitted to the hospital for IV ceftriaxone,” Dr. Meissner said. “Oral doxycycline gives adequate levels.”
Many uncomplicated pediatric cases of Lyme will probably still be treated with amoxicillin, which is well known and commonly used in children.
I wrote a couple of weeks ago about the serology test that we use for Lyme and its limitations; it measures the body’s immune response and is therefore not positive early in the infection, when you ideally want to make the diagnosis.
Lyme remains challenging for many reasons, not least because the bacteria that cause the disease cannot be easily grown in the lab, like strep. Without the ability to test directly for the organism, making that diagnosis early continues to depend on clinical assessment, not on the lab.
“About 80 percent of patients who have Lyme disease will have the rash of erythema migrans, and that’s a sufficient basis to start treatment,” Dr. Meissner said, referencing the signature rash, often resembling a target, which can appear (though it doesn’t always) soon after infection with the bacteria causing Lyme.
In these situations, “blood testing is not recommended because only about a third of people will have detectable antibodies when they present with erythema migrans,” he said. “If it’s the right season, if the rash has a quality that’s consistent with Lyme disease, and a person lives in an endemic area or visited an endemic area and particularly if there was a tick attachment, then it’s a clinical diagnosis,” he said.
The highest risk season is late spring and summer, when the young (and tiny) nymphal stage ticks are active and looking for hosts; adult ticks also play a role, and can transmit the disease during the spring and fall.
What about when parents do find a tick? First of all, Dr. Meissner said, testing the tick is not recommended. However, the length of time the tick was attached is relevant. And if you can tell that the tick is engorged, that may provide some information about whether it has been attached for long enough to make transmission a risk. Borrelia burgdorferi, the main type of spirochete bacteria that cause Lyme, live in the tick’s midgut, he said, and once the tick attaches to its host and begins its “blood meal,” it takes some time for the blood to activate the bacteria.
“The spirochete has to migrate to the mouth of the tick,” Dr. Meissner said. It then gets transmitted from tick to human by reflux, journeying out from the salivary glands as the tick is feeding on blood. “If the tick is attached for less than 36 to 48 hours, then probably there’s not enough time for the spirochete to activate and get to the salivary glands,” Dr. Meissner said. “That’s why tick checks are so important — if you can catch it before 36 hours, 48 hours, it’s less likely the spirochete will be transmitted.”
The transmission process is complicated for other reasons as well. Scientists are studying the elements in tick saliva, which contains anticoagulant that gets injected through the skin into the host’s capillaries.
The new recommendations also include post-exposure prophylaxis for children: a single dose of doxycycline to be given after an engorged tick has been removed, especially during the summer months, to reduce the risk of Lyme disease.
So we’ll have more options in treating children, and we know a lot more than we used to. But we’re still left giving the same preventive advice, which can leave people a little frustrated.
First of all, “minimize the chance that you’ll give the tick a chance to attack,” Dr. Meissner said. If you’re in an area with ticks, he said, try to stay in the middle of the path and don’t brush against the shrubs. “Ticks can’t jump.”
Use insect repellent, and reapply it after sweating or swimming. On skin, DEET, picaridin, IR3535 and oil of lemon eucalyptus, and on clothes, permethrin, have all been shown to repel ticks to some extent, depending in part on the individual formulation.
Wear light-colored clothing so ticks may be more easily visible. Tuck long pants into socks. Do tick checks, and try to remove the ticks before they have been attached long enough to feed.
“In the vast majority of cases, Lyme disease can be readily diagnosed and readily treated,” Dr. Meissner said. “If a child or an adult gets treated with the appropriate antibiotics in the early stages of Lyme disease, it’s rare for that person to develop the neurologic or cardiologic symptoms that can come if not treated.”
But it remains a highly fraught topic. By all means, take a look at the guidelines, which may still change and evolve.
“Many, many people have worked very hard on this,” Dr. Meissner said. “People who have no vested interest other than to provide the best care for patients who come to us.”
