When is joint aspiration indicated in the evaluation of Lyme disease?
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When is joint aspiration indicated in the evaluation of Lyme disease?
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@wyatt Joint aspiration for diagnostic reasons is unnecessary if only Lyme arthritis is suspected. However, arthrocentesis may be appropriate to exclude other causes of effusions, such as septic arthritis or, in adults, gout and pseudogout. In Lyme arthritis, joint fluid may have 25,000-125,000 white blood cells (WBCs)/µL, often with a polymorphonuclear predominance.
A retrospective study of children in areas where Lyme disease is endemic who presented with knee monoarthritis found that the presence of a peripheral blood absolute neutrophil count of 10 × 103 cells/mm3 or higher and an ESR of 40 mm/hour or higher predicted septic arthritis; no child with values below those cutoffs had septic arthritis. These researchers suggested that those criteria could be used to identify children with knee monoarthritis who are at low risk for septic arthritis and might not require diagnostic arthrocentesis.