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Pediatric Lyme Arthritis of the Hip: The Great Imitator?
Aristides I Cruz1, Francis J Aversano, Mark A Seeley
1*Hasbro Children's Hospital, The Warren Alpert Medical School at Brown University, Providence, RI †The Children's Hospital of Philadelphia, Philadelphia ‡Geisinger Health System, Danville, PA.
Insights
Children with hip pain in Lyme endemic areas are more likely to have Lyme arthritis (LA) if they lack fever and have a lower white blood cell (WBC) count. Elevated erythrocyte sedimentation rate (ESR) suggests LA over transient synovitis.
Area of Science:
- Pediatric Orthopedics
- Infectious Diseases
- Rheumatology
Background:
- Lyme arthritis (LA) of the hip mimics septic arthritis (SA) and transient synovitis (TS) in children.
- Differentiating these conditions is crucial for appropriate treatment.
Purpose of the Study:
- To identify clinical and laboratory markers distinguishing pediatric hip LA from SA and TS.
- To aid in the diagnosis of isolated hip LA.
Main Methods:
- Retrospective review of 93 pediatric hip aspirations in a Lyme-endemic area.
- Comparative analysis of clinical and laboratory data between LA, SA, and TS groups.
- Multivariable logistic regression to determine independent predictors of LA.
Main Results:
- Febrile history and higher peripheral white blood cell (WBC) count were associated with increased odds of SA versus LA.
- Elevated erythrocyte sedimentation rate (ESR) was linked to higher odds of LA versus TS.
- Absence of fever and lower peripheral WBC count predicted LA over SA.
Conclusions:
- Children with isolated hip effusions in endemic areas may have LA if they lack fever and have a decreased WBC count.
- Elevated ESR is a potential indicator of LA when compared to TS.
- This study addresses a gap in research on isolated hip LA in children.
Background:
Lyme arthritis (LA) of the hip can present similarly to septic arthritis (SA) and transient synovitis (TS). The primary purpose of this study was to determine clinical and laboratory parameters differentiating LA of the hip from SA or TS among children who had undergone hip aspiration during the evaluation of hip pain.
Methods:
This was a retrospective review of all patients who underwent hip aspiration for the evaluation of hip pain at a tertiary care children's hospital in a Lyme endemic area. Clinical and laboratory data were reviewed and comparative analyses were performed between those diagnosed with LA, SA, and TS. Independent samples t test, ANOVA, and χ test were used to compare clinical and laboratory variables as appropriate. Multivariable logistic regression was used to elucidate independent predictors of LA. Statistical significance was set at P<0.05.
Results:
Ninety-three hip aspirations (93 patients) were included in the final analysis. Seventeen patients were diagnosed with LA, 40 with SA, and 36 with TS. Multivariable logistic regression revealed febrile history (OR=16.3; 95% CI, 2.35-113.0) and increased peripheral white blood cell (WBC) count (OR=1.26; 95% CI, 1.01-1.58) to be significantly associated with increased odds of being diagnosed with SA versus LA. Increased erythrocyte sedimentation rate (ESR) was significantly associated with increased odds of being diagnosed with LA versus TS (OR=1.06; 95% CI, 1.02-1.10), whereas febrile history (OR=0.06; 95% CI, 0.01-0.49) and increased peripheral WBC count (OR=0.8; 95% CI, 0.65-0.98) were associated with decreased odds of LA.
Conclusions:
Children presenting in a Lyme endemic area with an isolated hip effusion are more likely to have LA versus SA if they have no history of fever and a decreased peripheral WBC count. Compared with TS, patients with LA are more likely to have an elevated ESR. This study adds to existing knowledge because there are few investigations examining isolated LA of the hip.
Level Of Evidence:
Level III-retrospective case-control study.
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