Lyme Disease in Infants: A 5-Week-Old Baby Girl Case Study
Lyme disease in infants is rarely discussed in the medical literature, yet babies living in endemic areas can still be exposed to infected ticks. In this Inside Lyme case study, I discuss a 5-week-old baby girl diagnosed with Lyme disease. Reviewing real clinical cases often provides important insight into how tick-borne illnesses appear in practice.
In this episode, I discuss a 5-week-old baby girl diagnosed with Lyme disease.
This case was described in the journal Pediatrics by Handel and colleagues in 2019.
Although uncommon, Lyme disease in infants can occur in endemic regions, particularly when ticks are brought into the home on pets or clothing.
The report reminds parents and clinicians to consider Lyme disease even in very young infants. The authors described a healthy 5-week-old baby girl who developed Lyme disease while living in Long Island, New York, an area endemic for Lyme disease.
The infant spent very little time outdoors. However, the family dog frequently went outside and may have brought ticks into the home. Other studies have reported a higher risk of Lyme disease in households with pets.
The parents did not initially recognize a tick. Instead, they removed what they described as “an engorged black bug from behind her left ear six days before symptoms began,” wrote Handel. This illustrates how difficult it can be for parents to recognize a tick bite.
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The fact that the tick was engorged was also important. The risk of Lyme disease increases significantly when a tick remains attached long enough to become engorged.
As a tick feeds, the number of Borrelia burgdorferi spirochetes increases. During the blood meal, the bacteria migrate from the tick’s midgut to the salivary glands, increasing the likelihood of transmission to the host.
Ticks can also be extremely small, particularly in their nymph stage. Many parents may not recognize a tick bite, which can delay recognition of Lyme disease.
Recognizing Lyme Disease in Infants
The baby was diagnosed with early disseminated Lyme disease.
The rash pattern was typical. The physicians described:
“multiple flat rings with peripheral blanching erythema, a central clearing, and outward expansion without tenderness or peripheral scaling.”
There was also a rash near the bite site.
Early disseminated Lyme disease can occur when the infection spreads through the bloodstream. In some patients, this stage appears without the classic single erythema migrans rash.
Recognizing these skin findings early is important, particularly in children and infants who may not be able to describe their symptoms.
Hospitalization and Evaluation
The infant was hospitalized with a fever of 101.1°F and irritability.
Tick-borne disease tests were negative, which is common during early Lyme disease before antibodies have developed. The Western blot Lyme disease test was not performed because the ELISA screening test was negative.
Early Lyme disease tests are frequently negative because antibodies may not yet have developed. In these situations, clinicians often rely on clinical judgment and the appearance of the rash.
The physicians were concerned about Lyme meningitis, an uncommon but important complication of Lyme disease in children.
A spinal tap was attempted but was unsuccessful.
Because of concern for possible Lyme meningitis, the physicians treated the infant with intravenous antibiotics. The baby received intravenous ceftriaxone for two weeks and was discharged without complications.
Follow-up evaluations showed no further problems.
Infants exposed to ticks may also be at risk for additional tick-borne infections such as Babesia or Anaplasmosis, although these are less commonly reported in very young children.
Lyme Disease in Infants
The authors noted that few published cases describe tick-borne illnesses in very young infants. However, the lack of published cases does not necessarily mean that these infections are rare.
According to the CDC, children under 5 years of age are among the age groups most commonly diagnosed with Lyme disease.
What Can We Learn From This Case?
- Babies can develop Lyme disease even with minimal outdoor exposure.
- Family pets may bring ticks into the home environment.
- Diagnosing Lyme meningitis in infants can be difficult. Even when a spinal tap is successful, results may still be negative in neurologic Lyme disease.
Questions Raised by This Case
- Would it have helped if the parents had recognized the “bug” as a tick?
- Would Lyme disease have been recognized if the rash had been single or atypical?
- Could the infant have been successfully treated with oral antibiotics instead of intravenous therapy?
- If the infant had not developed a rash, would clinicians have relied on clinical judgment to diagnose Lyme disease?
- Would an IgM Western blot have been positive if it had been ordered?
- Could early antibiotic treatment at the time of the tick bite have prevented hospitalization, spinal tap attempts, and intravenous therapy?
- When should a spinal tap be performed in infants suspected of having Lyme disease?
- Could the infant also have had co-infections such as Ehrlichia, Anaplasma, or Babesia?
- Will two weeks of intravenous antibiotics prevent later complications of Lyme disease?
Can Babies Get Lyme Disease?
Yes. Although Lyme disease in infants is uncommon, babies can become infected if they are bitten by an infected tick. Ticks may be brought into the home on pets or clothing, which means infants who spend little time outdoors can still be exposed.
Early recognition can be difficult because infants cannot describe symptoms and laboratory tests may be negative early in infection. For this reason, clinicians often rely on the appearance of the rash and clinical judgment when diagnosing Lyme disease in infants.
Treating Tick-Borne Disease in My Practice
In my practice, each patient requires a careful and individualized evaluation. I typically order a broad panel of laboratory tests including blood counts, liver and kidney function tests, thyroid studies, and screening for autoimmune diseases such as lupus and rheumatoid arthritis, along with testing for tick-borne infections.
Consultations with specialists such as neurologists, rheumatologists, and ophthalmologists may also be necessary.
Many Lyme disease cases are complex, as illustrated throughout this Inside Lyme Podcast series.
We need more physicians trained in diagnosing and treating Lyme disease in children. We also need better diagnostic tests to determine who has Lyme disease and when the infection has resolved.
Finally, we need clearer guidance on optimal treatment strategies for infants.
Cases like this remind clinicians and parents that Lyme disease can occur even in very young infants living in endemic areas, and early recognition remains essential.
Cases like this are discussed further in our Pediatric Lyme Disease guide, which reviews how Lyme disease appears in children and infants.
Physicians must also be given the clinical freedom to treat difficult cases without undue interference from insurance companies, medical boards, medical societies, or administrative restrictions.
References
- Handel AS, Hellman H, Hymes SR. Two Neonates With Postnatally Acquired Tickborne Infections. Pediatrics. 2019;144.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
