Clinical Characteristics of Multiple Erythema Migrans in Children: A Five-Year Retrospective Study

Multiple erythema migrans (MEM) is an early disseminated manifestation of Lyme borreliosis. Data describing its clinical presentation in children are limited, and treatment approaches differ between settings. We retrospectively reviewed children younger than 18 years diagnosed with MEM at the University Medical Centre Ljubljana, Slovenia, from 2021 through 2025. Demographic, clinical, laboratory, treatment, and outcome data were analyzed descriptively. Among 621 children with disseminated Lyme borreliosis, 445 (72%) had MEM. The median age was 5.0 years, and 78% were younger than 8 years. The median number of lesions was 4, and additional lesions usually appeared within a few days of the first lesion. Constitutional symptoms were reported in 28% of children, and routine laboratory findings were largely within age-adjusted reference ranges. Extracutaneous manifestations were uncommon. Most children (95%) received intravenous ceftriaxone. Pediatric MEM predominantly affected young children and usually followed an uncomplicated clinical course characterized by rapid development of additional skin lesions, limited constitutional symptoms, and largely unremarkable routine laboratory findings. Because almost all children received ceftriaxone, this retrospective study cannot compare treatment strategies. Prospective studies are needed to define the optimal antibiotic regimen for pediatric MEM.