Mommy, My Ankle Hurts!

By: Sean Dyer, MD

A 7 year old healthy girl presenting with left ankle pain for the past 2 days. She and her parents deny any trauma, the pain is made worse with walking and she hasn’t tried any medication for relief at home. She denies any fevers, chills, nausea, vomiting or recent colds.

Vitals:
HR: 89     BP: 98/54     T: 98.4     PO2: 99%     RR: 19

Physical Exam:
General: non-toxic, well appearing, appropriate for her age
Extremities: tenderness to palpation over L distal fibula, no L ankle tenderness, full ROM, mild swelling and erythema, no warmth or fluctuance overlying L distal fibula
Neuro: L foot sensation intact to light touch, DP pulse 2+, motor 5/5 in LLE

Imaging:
Left ankle xrays: normal joint alignment, no fracture, mild soft tissue swelling over distal fibula

  1. What is on your differential? What would be higher on your differential secondary to this patient’s age?
  2. Any further workup needed?
  3. What is this patient’s disposition?

ED Course:
This patient had a CBC, BMP, ESR and CRP drawn. Patient’s vitals were unchanged throughout her ER stay and her lab results were normal except for a elevated CRP 4.4 and ESR 20. As a result of the patient’s elevated inflammatory markers and point bony tenderness orthopedic service was consulted for concern of osteomyelitis. Patient was admitted to their service with the diagnosis of osteomyelitis which was later confirmed with an MRI and she was treated with IV clindamycin. Aspirations of the periosteum and blood cultures grew no organisms, a PICC line was placed and the patient was discharged home on IV antibiotics.

Credit: UpToDate

Discussion:
Osteomyelitis is a disease that affects both adults and children, but in different etiologies and circumstances. The majority of our adult patients with acute osteomyelitis tend to have an overlying wound or fracture and risk factors such as peripheral vascular disease or diabetes. Children differ in the fact that the etiology is more often than not hematogenous in nature. In addition, more than half of these cases occur in children less than 5 years old. Most cases occur in the metaphyseal region of children’s bones as those are the most vascular and the most fragile. Keep a high suspicion for osteo in kids, especially those that present with increased irritability or decreased appetite and focal signs of inflammation with negative xrays.

 

Resources:
NEJM: Acute Osteomyelitis in Children
Ped EM Morsels: Osteomyelitis in Kids