A Toddler’s Lyme Disease Misdiagnosed as Abuse

• • Sometimes a bandaid covers more than a scrape. Sometimes it covers a bigger story—one about misdiagnosis, fear, and the high stakes of misunderstanding Lyme disease in children.

    That’s what happened in a case reported by Dr. Pan and colleagues in the journal Case Reports in Orthopedics [2021]. A young boy’s swollen knee, fracture, and skin lesion were misinterpreted as signs of child abuse—when in reality, he had Lyme disease.

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    The Case: When Lyme Disease Mimics Trauma

    A 4-year-old boy was evaluated after an unwitnessed fall while playing outdoors. His pediatrician noted:

    1. A greenstick fracture of the radius

    2. A swollen right knee with mild tenderness

    3. A large “bruise” on the buttock

    Out of caution, and without a clear account of what had happened, the physician reported the incident to County Social Services for possible non-accidental trauma (NAT). The child was placed in foster care, and the case was investigated as suspected abuse.

    But as Pan and colleagues later wrote, a closer examination by an orthopedic specialist changed the trajectory:

    “What was initially interpreted as a large bruise on the buttock was in fact a Bull’s-eye rash—erythema migrans.” – Pan et al.

    The child’s Lyme disease test came back positive, and he was treated with a 30-day course of oral amoxicillin. His symptoms improved. Five days later, the child was returned to his family, and the investigation was closed.

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    What Pan et al. Want Us to Learn

    The authors caution that increased awareness of child abuse, combined with inadequate training, may lead to overreporting:

    “Less than 1 in 7 cases reported by professionals end up as confirmed abuse.” – Pan et al.

    That’s not an argument against mandated reporting—but a call for deeper clinical evaluation before conclusions are drawn. When Lyme disease is misread as trauma, the result can be unnecessary family separation and psychological harm.

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    Lessons for Clinicians: A Deeper Look

    Here’s what this case—and others I’ve seen in practice—can teach us:

    1. Recognize Non-Traumatic Joint Swelling in Children

    1. Lyme arthritis often presents as painless or minimally tender joint swelling, especially in the knee.

    2. It can occur without fever and without elevated inflammatory markers.

    3. It may be episodic or migratory, which is atypical for trauma or juvenile arthritis.

    2. Don’t Rely on Tick Bite History

    1. In most pediatric cases I’ve treated, parents never saw a tick.

    2. Children are often bitten behind the knee, in the scalp, or along the waistband.

    3. Absence of a tick bite does not rule out Lyme—especially in endemic regions.

    3. Learn to Identify Atypical Rashes

    • Erythema migrans is not always a textbook “bull’s-eye.” It may appear:

      1. Faint or bruise-like in children

      2. Solid red or purple (especially in darker skin tones)

      3. Located in unusual places like the buttock or groin

    • Clinicians must differentiate bruising from rashes, particularly when joint symptoms or systemic complaints are present.

    4. Assess Environmental Risk

    1. Ask whether the child has been in wooded, grassy, or rural areas.

    2. Tick exposure is more common in households with pets, outdoor play, or proximity to deer or wildlife.

    5. Avoid Premature Diagnostic Closure

    1. It’s tempting to conclude “abuse” or “trauma” when a child presents with injury and no witness.

    2. But jumping to conclusions without considering infectious, autoimmune, or environmental etiologies may do more harm than good.

    6. Coordinate with Specialists Cautiously

    1. If you consult orthopedics, pediatrics, or emergency medicine, ensure infectious etiologies like Lyme are not overlooked.

    2. Specialists may assume trauma unless explicitly asked to evaluate for alternatives.

    7. Protect Families from System-Induced Harm

    1. Mandated reporting is important—but false positives create real trauma.

    2. If Lyme or other medical conditions are suspected, consider expedited testing before reporting when the child is safe and stable.

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    When Lyme Disease Triggers CPS Fears

    Parents of children with Lyme disease often feel caught between two worlds:

    1. They’re seeking care for a child who seems sick, withdrawn, or in pain.

    2. But the symptoms—limping, bruising, emotional changes—may be misread as red flags.

    This case makes their fear tangible. As Pan et al. write:

    “Families are subjected to investigation, interrogation, separation, and punishment after a report is made.”

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    Final Thought: This Toddler’s Story Could Have Been Any Child’s

    This child received the right diagnosis—but only after being separated from his family. That’s a cost no child should pay for a delay in recognition.

    As clinicians, we must:

    1. Keep Lyme disease on our differential

    2. Respect the diverse ways it presents in children

    3. Work collaboratively across specialties and systems

    4. Use caution before reporting families whose children may simply be ill

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    📚 Citation:
    Pan T, Nasreddine A, Trivellas M, Hennrikus WL. Lyme Disease Misinterpreted as Child Abuse. Case Rep Orthop. 2021;2021:6665935. doi:10.1155/2021/6665935

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