Five key takeaways from latest Lyme disease guidelines
Lyme disease impacts more than 300,000 people annually, an expert told Infectious Diseases in Children Symposium attendees.
The geographical distribution of Lyme disease is spreading, and without a vaccine, cases are on the rise, Lise E. Nigrovic, MD, MPH, a senior associate physician in medicine at Boston Children’s Hospital and an associate professor of pediatrics and emergency medicine at Harvard Medical School, said. To help clinicians manage these patients, Nigrovic shared five key takeaways from the recent guidelines published by the Infectious Diseases Society of America, American Academy of Neurology and American College of Rheumatology.
According to Nigrovic, clinicians should consider administering prophylaxis to patients who present with an Ixodes tick bite if the tick had been in place for approximately 24 hours. The guidelines recommend that adults receive a single 200 mg dose of oral doxycycline within 72 hours of the tick’s removal, whereas children should start at a dose of 4.4 mg/kg and titrate up to a maximum dose of 200 mg. This is a strong recommendation with moderate-quality evidence, Nigrovic said.
Facial nerve palsy
When patients present with facial palsy, “the first rule is to figure out if it is central vs. peripheral,” Nigrovic said. Patients with peripheral facial palsy lose movement in their eyebrow, forehead and nasolabial folds; cannot close their eyes; and experience sagging eyelids and lower lips, according to Nigrovic. In central facial palsy, eyebrow and forehead functions are not affected, she said.
The guidelines offer no recommendation on corticosteroid use in conjunction with antibiotics for patients with Lyme disease-associated facial nerve palsy. A current lack of evidence hinders any recommendation in this area, Nigrovic said.
“There are some studies that are ongoing to address this more accurately,” she said. “In Northern Europe, where Lyme disease is also seen, there has been a study that just published a protocol, and they are going to enroll children with Lyme disease facial palsy to answer the question ... but it’s going to take a while.”
Peripheral nervous system manifestations
The latest Lyme disease guidelines also address neurologic manifestations. According to Nigrovic, IV ceftriaxone, cefotaxime, penicillin G or oral doxycycline should be used over other antimicrobials to treat Lyme disease-associated meningitis, cranial neuropathy, radiculoneuropathy or other peripheral nervous system manifestations.
She said an important part of implementing this recommendation is distinguishing between aseptic meningitis and Lyme meningitis. The latter condition may be ascertained with the rule of sevens, Nigrovic said. This rule categorizes children as low risk for Lyme disease-associated meningitis based on the absence of three factors: having a headache for 7 days or more, seventh or other cranial nerve palsy and a mononuclear cell count of 70% or more.
“The rule performs pretty well,” Nigrovic said. “The sensitivity is 98% ... the specificity was only moderate at 40% but the negative predictive value is high at 100%.”
Nigrovic noted that Lyme disease can cause carditis, which is often indicated by prolonged QT interval.
In hospitalized patients with Lyme carditis, the guidelines recommend IV ceftriaxone as the first line of treatment. Then, when evidence indicates the patient is improving, oral antibiotics can be used, Nigrovic said.
In patients with swollen joints, clinicians who suspect Lyme disease should still rule out septic arthritis before prescribing treatment, according to Nigrovic.
Patients with septic arthritis usually have absolute neutrophil counts of 10,000 cells/mm3 or higher and an erythrocyte sedimentation rate of 40 mm or greater per hour, Nigrovic said.
For patients who are diagnosed with Lyme arthritis, the guidelines recommend oral antibiotics for 28 days. Doxycycline is often used, Nigrovic said.