by Anne Whitehead, Inova Children’s Hospital
with Joelle Simpson, Children’s National

The Case
This is a case of a 5 yo previously healthy African American boy presenting with bilateral lower extremity pain, abdominal pain and fever. The challenge is determining an appropriate work up in a case with a broad differential diagnosis.

Here’s How You Answered Our Questions

The poll was mixed on imaging.  The differential diagnosis is broad.  Several providers wanted anti-pyretics and pain control with a repeat set of vital signs and repeat exam (particularly neuro exam and rectal tone) prior to obtaining imaging.  One provider commented that if the CK were grossly abnormal, she might hold off on imaging.  The poll was also mixed on whether to image the abdomen, spine or hips.  Some providers felt an AXR was warranted based on reports of constipation.  Other providers wanted a spine XR/CT/MRI to assess for a hematoma/mass/abscess/etc.  Although several voted on hip imaging, people who attended conference felt that this was lower yield, as the hip pain is bilateral in nature.

Denouement
A CT abdomen/pelvis was performed and showed a large stool burden, but no other abnormalities identified.  Hip joints visualized on CT showed no effusions or other abnormality. Bilateral femur XRs were also normal.

Further history was obtained from the mother, who recalled that “something was positive on the newborn screen” but she had never followed up on it.  In the setting of severe limb pain with normal imaging studies and a microcytic anemia, a hemoglobinopathy was suspected.  Mom reported she had a history of sickle cell trait when specifically questioned.  She denied similar previous pain crises in the patient.  Due to suspicion for a hemoglobinopathy, blood cultures (which were ultimately negative) were sent and ceftriaxone given in the ED.  The child was seen by orthopedics in the ED who had low suspicion for septic arthritis.

During hospitalization, hemoglobin electrophoresis confirmed sickle cell beta thalassemia.

Teaching Points from Thursday Conference
The Children’s Hospital of Wisconsin has an AWESOME clinical algorithm for work up of a child with lower extremity musculoskeletal pain.

Localize the lesion: