Pediatric emergency medicine trisk 0911 0911

young children. This infection is frequently characterized by mild clinical
symptoms, lack of leukocytosis and relatively low concentrations of acute-phase
serum reactants and would be missed on such algorithms. A blood culture should
be obtained in patients with concern for osteomyelitis, abscess, or septic arthritis.
Laboratory studies are also indicated in the absence of fever if the child has been
limping for several days without evidence of trauma on plain films. While
rheumatoid factor is typically negative in children with JIA, antinuclear antibody
testing is frequently positive in patients with the oligoarticular and polyarticular
forms of JIA. Acute lymphocytic leukemia (ALL) may present with
musculoskeletal complaints; bone and joint pain often begin before the
appearance of blasts in the peripheral blood. Children with evidence of infection
or inflammation with a joint effusion may require arthrocentesis for definitive
diagnosis. In areas of endemic Lyme disease, Lyme testing should be performed
in a patient with monoarticular arthritis. A creatine phosphokinase level may be
helpful if muscle inflammation is suspected.
When the initial history, physical examination, imaging, and laboratory
evaluation indicate the cause of the limp, specific treatment can be initiated.
Abnormalities in the initial workup without a definitive diagnosis should prompt
further imaging or laboratory studies. Computed tomography is an excellent
imaging modality for cortical bone. It serves as a useful diagnostic adjunct in
certain fractures, bony coalitions, and bone tumors. Ultrasound is the preferred
modality for diagnosing hip effusions; it is also useful for guiding needle
aspirations of the hip joint. While historically ultrasonography was only
performed by radiologists, point-of-care ultrasound (POCUS) to quickly identify
hip joint effusions is becoming increasingly common in pediatric emergency
medicine. Magnetic resonance imaging has become the gold standard for the
diagnosis of musculoskeletal infections and Perthes disease. It can additionally be
useful in the workup of malformative conditions, rheumatologic disease,
oncological tumors, and hematologic malignancies. Historically, MRI was best
utilized with well-localized symptoms rather than as a screening tool. However,
technological advances in whole-body MRI and lack of radiation exposure

increase the appeal of MRI over bone scintigraphy in many situations. The latter
remains an option where MRI is not readily available. In a prospective study of
limping children with ESR >10 mm/hr or CRP >10 mg/L, 75% had positive MRI
findings leading to a definitive diagnosis.
If the initial workup in a limping child is completely normal, including
screening radiographs and laboratory studies, the child may be followed closely
as an outpatient. The child should be examined frequently (e.g., every few days)