Growing Pains or Lyme Disease? How to Tell the Difference
Growing pains and Lyme disease can appear similar.
Joint swelling and limping are important warning signs.
Delayed recognition may prolong pediatric Lyme arthritis.
A nine-year-old complains of knee pain at bedtime. A twelve-year-old wakes up crying with leg aches. A teenager limps after soccer practice.
When children report joint or muscle pain, “growing pains” often becomes the default explanation—delaying investigation of Lyme disease.
Understanding the differences between growing pains and Lyme disease may prevent months of dismissed symptoms while treatable infection damages joints.
For a broader discussion of why Lyme disease is frequently overlooked in children, see Pediatric Lyme Disease: Why Children Are Often Misdiagnosed.
Why Growing Pains and Lyme Disease Get Confused
Both conditions may cause leg and joint pain during active growth years and may worsen with activity. These similarities sometimes lead clinicians to dismiss Lyme arthritis as growing pains.
Growing pains represent a diagnosis of exclusion—applied when no other cause is identified. When Lyme disease produces joint pain, this label may delay testing and treatment.
The critical differences involve timing, pattern, physical findings, and associated symptoms.
When Growing Pains Aren’t Growing Pains
True growing pains occur in muscle tissue, appear exclusively at night, and resolve completely by morning. Children walk, run, and play normally during the day.
Growing pains do not cause limping, swelling, fever, or limitation of movement.
Red flags requiring investigation include:
- Visible swelling of knees, ankles, or other joints
- Persistent pain lasting days or weeks
- Daytime symptoms interfering with activities
- Limping or refusal to walk
- Pain inside joints rather than muscles
- Migratory pattern—pain moving between joints
- Associated symptoms including fever, rash, fatigue, or headaches
- Recent tick exposure or outdoor activities in endemic areas
Even one red flag may warrant investigation.
How Lyme Arthritis Presents in Children
Lyme arthritis typically affects large joints, particularly the knee.
Children may develop visible swelling, warmth, and limitation of movement persisting for days to weeks. Pain may migrate from knee to ankle to wrist over weeks or months.
Children may limp, avoid stairs, or refuse to participate in sports. Parents often notice behavioral changes as previously active children become sedentary because movement hurts.
Lyme arthritis frequently appears months after initial tick exposure, long after any rash or fever has resolved. Many children do not recall a tick bite. This delayed onset contributes to misdiagnosis as growing pains.
The Diagnostic Challenge
Growing pains is a clinical diagnosis that generally requires no testing. When clinicians hear “leg pain at night,” reassurance may be provided without further evaluation.
This approach fails when Lyme disease is the underlying cause.
Children with true Lyme arthritis typically demonstrate positive serology because joint symptoms often appear later when antibody response is established.
A child with persistent knee swelling following summer camp deserves Lyme testing even if parents initially describe “growing pains.”
Why This Distinction Matters
Growing pains require no treatment beyond reassurance. Children typically outgrow the condition without intervention.
Lyme arthritis requires antibiotics. Without treatment, inflammation may persist, and some children develop chronic arthritis capable of damaging cartilage.
Early treatment may prevent these outcomes.
The growing pains label may delay diagnosis for months while families wait for symptoms to resolve. By the time Lyme disease is recognized, children may have experienced unnecessary pain and more difficult recovery.
Frequently Asked Questions
How can I tell if my child has growing pains or Lyme disease?
True growing pains occur only at night in muscles rather than joints, last 10–30 minutes, and do not cause limping or swelling. Lyme arthritis causes persistent daytime joint pain, swelling, and often limping.
Can Lyme disease cause leg pain at night?
Yes, but Lyme arthritis usually also causes daytime symptoms. Persistent daytime pain, swelling, or limping should prompt evaluation beyond growing pains.
What does Lyme arthritis look like in children?
Lyme arthritis commonly causes visible knee swelling, warmth, and limitation of movement. Children may limp, avoid stairs, or stop participating in sports.
Do growing pains cause knee swelling?
No. True growing pains do not cause visible swelling, warmth, or limitation of joint movement. Any swelling requires medical evaluation.
Can a child have both growing pains and Lyme disease?
While theoretically possible, persistent joint-based or daytime pain should be evaluated for Lyme disease rather than attributed solely to growing pains.
Clinical Takeaway
Growing pains occur at night in muscles and resolve completely by morning. Lyme arthritis produces persistent joint inflammation, swelling, daytime symptoms, and functional impairment.
Joint swelling, limping, daytime pain, or migratory symptoms should prompt evaluation for Lyme disease rather than reassurance alone.
Related Articles
- Lyme Disease Misdiagnosis
- Lyme Disease Symptoms Guide
- MRI Can Help Identify Lyme Arthritis in Children
- Is My Child’s ADHD Actually Lyme Disease?
References
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- Gerber MA, Shapiro ED, Burke GS, et al. Lyme disease in children in southeastern Connecticut. N Engl J Med. 1996;335(17):1270-1274.
- Uziel Y, Hashkes PJ. Growing pains in children. Pediatr Rheumatol Online J. 2007;5:5. doi:10.1186/1546-0096-5-5.
- Lehman PJ, Carl RL. Growing pains. Sports Health. 2017;9(2):132-138. doi:10.1177/1941738117692533.
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
