Pediatric emergency medicine trisk 0936 0936

In children with localized adenopathy that persists past 2 to 4 weeks, ill-appearing
children, and children with generalized lymphadenopathy, further evaluation should be
performed, guided by the differential diagnosis that was formed based on history and
physical examination. Any suspicion of malignancy warrants assessment with CBC with
differential and peripheral blood smear examination, as well as chest radiograph to assess
for mediastinal adenopathy. In addition, lactate dehydrogenase and uric acid may be
elevated, indicating tissue damage and rapid cell turnover. Inflammatory markers,
including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are
nonspecific, but may be elevated in children with systemic inflammatory diseases and can
be helpful in monitoring response to treatment. In children with nonspecific infectious
symptoms, viral serologies (EBV, CMV, HIV) may be informative. As indicated by
history and examination, serology for B. henselae, or tuberculin skin testing or serum
testing for M. tuberculosis may be performed.
Various imaging modalities may aid in the diagnosis of lymphadenopathy, including
ultrasound (US), CT, and MRI. The type of diagnostic radiology necessary to evaluate
lymphadenopathy depends on the location and chronicity of the lymph node(s). In efforts
to limit radiation to doses as low as reasonably achievable (ALARA principle), US has
proven to be a very effective, noninvasive, inexpensive, highly available, and
nonradiating type of imaging to evaluate lymphadenopathy in children. US can
distinguish between simple node enlargement and a suppurative lesion with higher
sensitivity than CT. Color Doppler imaging can demonstrate increased blood flow to
inflamed lymph nodes as well as a hypoechoic (dark) center in a suppurative node.
Characteristics of the grouping of the lymph nodes can also aid the radiologist in
narrowing the patient’s differential diagnosis. It is important to note that children age >1
year with neck swelling ≤3 days are at low risk of having US findings that require
surgical drainage. CT may be preferred in the evaluation of lymphadenopathy when
greater anatomic detail is desired, as in a preoperative radiologic evaluation or in the
evaluation of deep cervical space neck infections. Contrast-enhanced CT is more sensitive
than US for the diagnosis of an abscess but lacks specificity due to the similar radiologic
appearance of frank pus and phlegmonous changes. MRI may provide these fine details
without ionizing radiation, but the cost of imaging and need for sedation make CT a more

preferable and easily accessible modality when accessed from the emergency department.
Finally, in the course of evaluation of lymphadenopathy, the decision to perform a
biopsy on an enlarged node remains a clinical one. In general, early node biopsy should
be considered in children who are ill with systemic symptoms, persistent fever, or weight
loss. Deep inferior cervical or supraclavicular adenopathy, with or without an abnormal
chest film, is pursued aggressively with biopsy, given the concern for malignancy, in
particular lymphoma. Beyond this, in the face of an otherwise negative diagnostic
workup, serial measurement over a period of weeks showing progressive or rapid
enlargement of the affected node raises suspicion for malignant disease and biopsy should
be strongly considered. Biopsy should also be considered if an enlarged node fails to
regress in size after approximately 6 weeks of observation.