Originally published at Pediatric EM Morsels on February 7, 2014. Reposted with permission.

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In the past we have discussed how prolonged fever in the Pediatric Patient should cause you to think “outside of the box.”  Kawasaki Disease often comes to mind.  Naturally malignancy should also be considered and a thorough history (any Back Pain?) and physical exam (any concerning lymphadenopathy) should be done looking for any red flags.  One entity that can be overlooked if not specifically considered is Osteomyelitis.

Acute Osteomyelitis in Kids

• If not diagnosed and treated promptly, can lead to significant Morbidity and Mortality!
• In kids, osteomyeltis most often develops from a hematogenous source.
  • Other causes:
    • Local spread from cellulitis or septic arthritis
    • Direct inoculation from traumatic injury

The Bugs

• Staph aureus is the most common pathogen associated with Osteomyelitis.
• Methicillin-Resistant Staph aureus is becoming more prevalent.
  • MRSA has been associated with higher temperatures and greater tachycardia.
• Respiratory pathogens (Strep pyogenes and Step pneumoniae) are also common.
• Kingella kingae is noted to becoming very common in kids less than 4 years of age.
• Salmonella species needs to be considered in patients with Sickle Cell Disease.
  • Still debated whether Salmonella or Staph is the most common in patients with Sickle Cell Disease.
  • It doesn’t really matter… you need to cover for both in the patient with Sickle Cell Disease!!

How Osteomyelitis may present

• Osteomyelitis can affect any bone, and as such, has a variety of presentations.
  • Femur (23-29%)
  • Tibia (19-26%)
  • Humerus (5-13%)
  • Pelvic Girdle (3-14%)
  • Spine (1-4%)
  • Clavicle (1-3%)
• Classically:
  • Fever
  • Inability to walk / limping or bear weight on that extremity
  • Focal tenderness
  • May have Redness and Swelling of associated area.
• Should be consider also when:
  • Fever without a source (particularly, if prolonged)
  • Clinical condition deteriorates.
  • Child complains of Back Pain.

Diagnostic Considerations

• No blood test is diagnostic.
  • CRP and Proclacitonin levels are sensitive, but most useful in follow-up.
• Imagining
  • Scintigraphy is sensitive and can help locate poorly localized illness.
  • CT can be useful, but obviously comes with increased radiation.
  • MRI is considered by many to be the best imaging method.
• Cultures
  • Blood cultures should be drawn, but only identify organism in 40% of cases.
  • Bone samples are often the best way to determine the organism.

Antibiotic Choices

• Bone penetration of the antibiotic and the most likely causative organisms are the primary concerns when selecting the initial antibiotics.
• Clindamycin or 1st Generation Cephalosporin are good initial choices.

Some More Interesting Considerations

• Osteomyelitis and Septic Arthritis

  • Osteomyelitis occurs concurrently with septic arthritis 17% – 33% of the time.
  • Thought to be due to contiguous spread of the osteomyelitis into the joint space.
  • When is concurrent infection more likely?
    • In Kids < 4 months and Adolescents (13 – 20 yrs).
    • When involving the Shoulder (72% of shoulder infections were concurrent).
    • When there is prolonged course of clinical symptoms (median of 6 days).
  • Concurrent infection is associated with increased morbidity (obviously).
  • Advanced imaging (MRI, Bone Scan, CT) is recommended when these risk factors are present.

• Osteomyelitis vs Vaso-Occlusive Crisis in Pt with Sickle Cell Disease

  • Sickle Cell patients are more susceptible to serious bacterial infections (impaired immune system and functional asplenia).
  • Vaso-occlusive crisis and osteomyelitis can present with similar symptoms (pain, fever, swelling, redness).
  • Factors that should raise suspicion for osteomyelitis in patients with sickle cell disease?
    • Prolonged pain
    • Prolonged fever
    • Swelling
    • Fewer painful sites (1 vs 2 or more)
  • So, maybe that child who presents with persistent bone pain is more than just a “typical sickle pain crisis.”

• Surgical Role

  • Naturally, since the bone is involved, you should consult the Orthopaedic Team (they would like to be involved before antibiotics are administered — at least in my experience).
  • Whether surgical drainage (outside initial biopsy) is beneficial is still debated.
  • Conservative treatment is effective in up to 90% of cases of acute osteomyelitis.

   

References