Lyme disease: What to know, how to treat and when to refer

Image of the deer tick, which transmits Lyme disease
Lyme disease is transmitted by the deer tick.

We asked pediatric infectious disease specialist Catherine Lachenauer, MD, of the Boston Children’s Hospital Division of Infectious Diseases, to answer some frequently-asked questions about Lyme disease in children. Here’s what she had to say:

How common is Lyme disease and what are some early symptoms?

Lyme disease is the most common tick-borne infection in the US. The number of reported cases has been rising over the years.

One of the best recognized and earliest symptoms of Lyme disease is the erythema migrans, or EM rash, that may appear within the first month (usually within the first two weeks) following the tick bite.  The EM rash occurs at the site of the bite, typically as a circular red rash that enlarges over the course of several days.  Often, there is clearing as the rash enlarges such that it appears as a “bullseye,” although it may also be a solid, or confluent, rash.  Patients may also have non-specific, flu-like symptoms including fever, headache, joint aches and fatigue, as early symptoms of Lyme disease.

A tick needs to be attached for at least 48 hours to transmit the Lyme-causing bacteria

What are some later-stage symptoms of Lyme disease in children?

Most symptoms of Lyme disease occur in three stages: early localized, early disseminated and late-stage disease.

In the early localized stage, usually within one to two weeks following the tick bite, a single EM rash may appear. Patients who are not diagnosed and treated with antibiotics in the early localized stage, they may go on to have symptoms of early disseminated disease.

In the early disseminated stage, a patient may experience multiple EM rashes. He or she may also show symptoms of meningitis or a seventh cranial nerve palsy (which looks like a Bell’s palsy). At this stage, there may also be cardiac involvement, or Lyme carditis, which most commonly causes a rhythm disturbance that may not cause any symptoms. In the second stage, patients may also have flu-like symptoms, such as fever, joint aches and fatigue.

The most common manifestation of late-stage Lyme — which may occur weeks to months after the tick bite — is arthritis, or joint swelling. Lyme arthritis usually affects one knee but may involve other large joints. Most patients with Lyme arthritis don’t have fever or other signs of illness.

How is Lyme disease treated in children? At what point should a pediatrician refer a patient to a specialist?

A two to four week course of oral antibiotics, depending on the symptoms, is appropriate treatment for most patients with Lyme disease. For children 8 years of age and older, the preferred medication is doxycycline.  For younger children, amoxicillin is usually given. Intravenous antibiotics are generally reserved for patients who present with meningitis, symptomatic heart disease requiring hospitalization, recurrent arthritis refractory to oral treatment or some other less common manifestations.

Overall, most pediatric cases of Lyme disease are easily treated with oral antibiotics. But patients with signs or symptoms suggestive of meningitis or symptomatic Lyme carditis should be referred to an emergency department or other specialty care for evaluation.

What other tick-borne illnesses should pediatricians be aware of this summer?

There are several Lyme coinfections, which are infections that may also be transmitted by the deer tick.

Borrelia miyamotoi is a bacterium, distantly related to the Lyme bacterium, that most commonly causes a febrile illness. There may also be headaches and relapsing fevers. Borrelia miyamotoi is treated with the same antibiotics that are given for Lyme disease.

Anaplasmosis is a  bacterial infection that may be asymptomatic or may cause symptoms ranging from a non-specific febrile illness to (in rare cases) severe illness. Clues to anaplasmosis include elevated liver enzymes or a low white blood cell count. Like Lyme disease, the preferred treatment for anaplasmosis is doxycycline. As a result, many patients who are treated for suspected Lyme are also treated for anaplasmosis at the same time.

Babesiosis is an illness caused by a parasite, Babesia microti, that infects red blood cells. Babesiosis may be asymptomatic or may cause a non-specific flu-like illness. In some patients, particularly in those without a spleen or with other immunocompromising conditions, Babesiosis may cause a severe or prolonged infection. Babesiosis is treatable with antibiotics, although requires a different course than those used to treat Lyme disease.

Finally, Powassan virus can also be transmitted by the deer tick. We have seen some increasing media coverage of Powassan virus disease but it is not common. Many patients with Powassan virus disease will not have any symptoms, although some patients may go on to develop a brain infection, or encephalitis. There is no specific treatment for Powassan virus.

What can parents do to prevent their children from getting Lyme disease?

A tick needs to be attached for at least 48 hours to transmit the Lyme-causing bacteria. That means regular, daily tick checks should be performed during the seasons that we spend time outdoors. Deer ticks are very small, ranging from the size of a poppy seed to a sesame seed, so wearing light-colored clothing and long sleeves can help us spot them more easily and prevent them from crawling on the skin. DEET-containing insect repellent, used according to package directions, can also prevent tick bites.

Encourage kids to be mindful of ticks, make preventative tick checks a regular part of the family routine and don’t be afraid to get outdoors and enjoy health-promoting activities!