Pediatric bone and joint infections: Clinical

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Pediatric bone and joint infections: Clinical

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A 15-year-old girl comes to the emergency department because of left knee pain. She states the pain has been increasing for the past 2 weeks. She also reports fevers, diffuse joint pain, and a history of sickle cell disease. Her temperature is 38.3°C (100.9°F), pulse is 88/min, respirations are 20/min, and blood pressure is 122/82 mm Hg. Physical examination shows the left knee is erythematous, warm, swollen, and tender to palpation over the tibial prominence. Radiographs of the knee show soft tissue edema and a large radiolucency in the proximal tibia. Which of the following is the most likely infectious organism?

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Bone and joint infections comprise mostly of osteomyelitis and septic arthritis, or a combination of the two.

In osteomyelitis, infections most often occur at the ends of long bones where they meet to form joints like the hip and knee, and in septic arthritis, they occur in the joints.

The source of infection may be hematogenous, secondary to close-by infection or secondary to direct inoculation from trauma and surgery.

Diagnosis is mostly clinical, and it’s based on the rapid onset and localization of symptoms.

Individuals mostly present constitutional symptoms like irritability, decreased appetite or activity, tachycardia, malaise, and fever.

Local signs consist of warmth, swelling, point tenderness around a bone or joint, and cellulitis. Joint stiffness is also common, with single joint involvement being more characteristic for bacterial infections.

If the clinical signs raise suspicion of infection, the next step is asking for additional tests to confirm or infirm diagnosis.

Let’s start with osteomyelitis, which is an infection of the bone. It is usually caused by Staphylococcus aureus, with community-acquired methicillin-resistant S. aureus or MRSA accounting for many of the cases, especially in posttraumatic, post-surgical, and vertebral osteomyelitis.

Vertebral osteomyelitis is also caused by Mycobacterium tuberculosis in about a quarter of the cases.

Additionally, Salmonella species and Streptococcus pneumoniae are commonly found in those with sickle cell disease; Gram-negative bacteria, such as Pseudomonas species or Escherichia coli, are common in infections after puncture wounds of the feet or open injuries to bone, and Staphylococcus epidermidis in some of those with prosthetic devices.


Osteomyelitis and septic arthritis in children are serious conditions, which need prompt management. They often result from bacterial infection, and if untreated, they can lead to severe complications such as joint damage, disability, disseminated infections, and sepsis.

Osteomyelitis refers to an infection of bones, often caused by bacteria such as Staphylococcus aureus and Streptococcus pneumonia. Symptoms of osteomyelitis can include fever, swelling, redness, and severe pain in the affected bone. Septic arthritis refers to an infection of the joint, also commonly caused by a bacterial infection. Symptoms of septic arthritis can include fever, joint pain, and redness and swelling in the affected joint.

Treatment for both conditions involves antibiotics, and sometimes surgery. Antibiotics are given to help eradicate the infection and prevent further spread, while surgery may be necessary to remove any infected tissue or to drain any abscesses.


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