It is not uncommon for me to see a patient whose parents are concerned about a recent tick bite. After all, I practice in an area where Lyme disease and other tick-borne illnesses are endemic. In the past, we provided reassurance and guidance about worrisome symptoms that would warrant antibiotic treatment and/or testing. But that all changed with the publication of clinical practice guidelines for Lyme disease in 2020.
This week, Pediatrics is early releasing a Pediatrics Perspectives article by Drs. Cody Meissner from Tufts University and Allen Steere from Harvard University, entitled, “Management of Pediatric Lyme Disease: Updates from 2020 Lyme Guidelines” (10.1542/peds.2021-054980), which summarizes the pediatric-specific guidelines.
The biggest change is the recommendation for antibiotic prophylaxis if there is a high-risk tick bite – specifically, if the tick is Ixodes species, the bite occurs in a highly endemic area (most Lyme disease occurs in the northeast quadrant of the US), and if the tick has been attached for at least 36 hours. A single dose of doxycycline (4.4 mg/kg, maximum 200 mg) is recommended for all ages.
What about the child’s teeth? Won’t they be permanently stained by the doxycycline? It turns out that the only evidence for teeth staining is for older tetracyclines; this has not been reported with doxycycline – and experts think that a single dose is safe.
For those tempted to use amoxicillin instead for prophylaxis, it is not recommended for post-exposure prophylaxis because of amoxicillin’s short half-life (approximately 1 hour) versus the longer half-life (16-22 hours) for doxycycline.
For the longer treatment required for actual Lyme disease, whether it be erythema migrans, arthritis, or carditis, amoxicillin is the drug of choice for those younger than 8 years, while doxycycline should be used for older children.
You will want to read the entire article so that you are up to date on the recommendations for diagnosis (for example, when lab testing is recommended and what type to order) and treatment of Lyme disease. There is also an update on prospective vaccines that may be on the horizon. You will then be ready for the next patient who calls or walks into your office after a tick bite.