Antibiotics Knock Out Lyme in Kids

SAN FRANCISCO -- Most children with symptoms of early disseminated or late Lyme infection experienced prompt improvement after starting antibiotics, researchers reported here.

A review of pediatric patients seen at a hospital in Washington, D.C., found that symptoms typically resolved within six months after starting treatment, and long-term consequences were uncommon, according to Mattia Chason, MD, from Children's National Health System.

The most frequent presentation of early disseminated Lyme disease was meningitis, usually indicated by headaches, and children with late disease often developed knee arthritis with swelling and pain, Chason's group reported at the Pediatric Academic Societies meeting here.

"In an endemic area, Lyme is something that can present all year round," Megan Reinhard, a student at the University of Minnesota in Minneapolis and study author, told MedPage Today. "A lot of people like to believe it's in the summer, when you're out and in the woods, but we actually found the highest number of cases in the fall. Lyme in an endemic area is the leading cause of monoarthritis in children all year round."

Reinhard presented a separate study at the meeting looking specifically at Lyme arthritis and how to distinguish it from septic arthritis.

Lyme disease, caused by Borrelia burgdorferi bacteria, is transmitted by ticks that live on deer and other mammals. It is increasingly common in the northeast, mid-Atlantic, north-central, and west coast regions of the U.S., according to the CDC.

Signs of initial infection may include fever, muscle and joint aches, and a distinctive erythema migrans rash. Early disseminated disease, which occurs weeks or months after infection as the bacteria spread throughout the body, may involve headaches, stiff neck, and facial palsy. Manifestations of late disease may include heart problems and arthritis in a single joint (monoarthritis), typically the knee.

The Infectious Diseases Society of America (IDSA) recommends treatment with doxycycline, amoxicillin, or cefuroxime. While it is not uncommon for symptoms to linger for a few months, only a small proportion of patients develop post-treatment Lyme disease syndrome, with persistent symptoms such as fatigue and pain lasting longer than six months.

Chason's group set out to describe the natural history of early disseminated and late Lyme disease in children, including time to resolution of symptoms after starting antibiotic therapy and ongoing symptoms after completing treatment.

They explained that there's been controversy regarding the frequency and etiology of subsequent prolonged non-specific symptoms despite receiving antimicrobial treatment.

Their retrospective analysis included 79 children (mean age 9.8 years) admitted to Children's National Health System between June 2008 and May 2015 who had laboratory-confirmed Lyme infection. Most (86%) had received no prior Lyme treatment, but among those who did, only one was deemed to have received an appropriate drug and dosage.

Just under half (37 patients, or 47%) presented with early disseminated Lyme disease, Chason's group reported. The most common manifestation was meningitis, seen in 81%. Cranial nerve palsy (27%), carditis (19%), and multiple erythema migrans rashes (18%) were less frequent. Most children with meningitis had headaches (88%), with smaller numbers experiencing nuchal rigidity (38%) or light sensitivity (19%).

Headaches resolved soon after starting antibiotic treatment, with 85% showing improvement within seven days. Half the patients with facial palsy experienced full resolution within two months after starting antibiotics, and the rest sought no further care after completing treatment.

The remaining 42 children (53%) had late Lyme disease manifesting as arthritis, mostly monoarthritis of the knee (93%). A majority had knee swelling for less than seven days before seeking care. Among 30 patients with post-treatment follow-up, arthritis resolved within a week in 17%, but in 38% this took more than two weeks, and in 30% it took more than a month. Resolution took significantly more time for children who had arthritis longer before seeking care, the researchers said.

Three-quarters of the children sought no further follow-up care after completing treatment. Of the 20 patients with post-treatment follow-up visits, half reported residual symptoms during the months after treatment, but 90% had complete resolution by six months. This left two children who reported ongoing symptoms including headache, decreased energy, and fatigue.

"The vast majority of pediatric patients with early and late Lyme improved promptly following appropriate antibiotic treatment, with a low incidence of post-treatment Lyme symptomatology," Chason's group concluded.

In a related study, Reinhard's group looked at the epidemiology and common clinical presentation of Lyme arthritis among children in Minnesota, one of the states with the highest number of Lyme cases in the U.S. Scanning electronic medical records from January 2011 through July 2016, they identified 74 patients (mean age 9.4 years) with joint swelling or pain who tested positive for Borrelia burgdorferi in their synovial fluid.

Twelve children were initially taken to the emergency department for arthritis, while 64 saw primary care providers. Almost all had arthritis of the knee, but one had arthritis of the elbow and another had arthritis of the hip. Only 40% of the children or their parents could recall removing a tick or spending time in a wooded area, and none remembered having an erythema migrans rash.

Children with Lyme arthritis had elevated white blood cell counts in their synovial fluid, but normal levels in circulating blood. Erythrocyte sedimentation rate and C-reactive protein levels were only mildly elevated. These markers were similar to those seen in patients with septic arthritis, limiting their usefulness for distinguishing between the two types, Reinhard said. However, she noted that children with septic arthritis usually had more pain and were less able to bear weight and walk.

"Kids are coming in and being diagnosed with septic arthritis rather than Lyme arthritis, leading to more hospitalization, surgical washout, and IV antibiotics," Reinhard told MedPage Today.

"Diagnosis of Lyme arthritis can be done with simple Lyme screening," she said. "We're encouraging primary care providers, emergency department docs, and anybody who comes in contact with these kids with monoarthritis to think of Lyme arthritis in an endemic region. If that test is negative, we can rule out Lyme within an hour -- it doesn't hurt to run it."

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