In children, how accurate is the clinical suspicion for Lyme disease in areas of high prevalence?
For children with suspected Lyme disease but without a classic bull's-eye lesion (erythema migrans of at least 5 cm), check serology rather than rely on your clinical impression. In this study, 12% of the children not suspected of having Lyme disease did have Lyme disease, and 31% of children thought to have Lyme disease did not have serologic findings at that time or within 30 days. (Level of Evidence = 1b)
The researchers assembled a convenience sample of children, one year and older, who underwent evaluation for Lyme disease at one of five hospital emergency departments in endemic areas, mostly on the east coast of the United States (one site was in Wisconsin). The children were evaluated by clinicians who had received training on the diagnosis of Lyme disease. The diagnostic criterion was a single characteristic lesion of at least 5 cm in diameter with or without central clearing, or a single smaller but enlarging lesion associated with a known or suspected tick bite and a known interval between the bite and the onset of the lesion. Lyme disease was confirmed in 23% of the 1,021 children via a positive two-tiered serology result within 30 days of presentation (82.4% of diagnoses) or a physician-diagnosed erythema migrans lesion at the time of presentation. Clinician suspicion in cases without clear erythema migrans was minimally accurate in ruling in or ruling out Lyme disease (concordance statistic = 0.75; 95% confidence interval, 0.71 to 0.79). Of the 554 children (54%) thought to be unlikely to have Lyme disease, 12% had a positive laboratory diagnosis, and 39 (31%) of the 127 children deemed to be very likely to have Lyme disease by clinicians did not have Lyme disease.
Study design: Cohort (prospective)
Funding source: Foundation
Setting: Emergency department
Reference:NigrovicLEBennettJEBalamuthFet alPedi Lyme NetAccuracy of clinician suspicion of Lyme disease in the emergency department. Pediatrics2017;140(6):e20171975.