A 6-year-old boy with homozygous sickle cell disease presents with fever and focal bony tenderness over the left tibia. Blood cultures are drawn before antibiotics. Compared with children who do not have sickle cell disease, which organism is disproportionately the most common cause of his osteomyelitis?

• A Salmonella species ✓
• B Staphylococcus aureus
• C Streptococcus pyogenes
• D Haemophilus influenzae type b

Explanation

In the general pediatric population Staphylococcus aureus causes the majority of osteomyelitis. In sickle cell disease, functional hyposplenism and impaired complement mediated opsonization of encapsulated organisms make nontyphoidal Salmonella the leading cause of osteomyelitis, often multifocal and involving long bones. Staphylococcus aureus remains the second most common pathogen, so empiric coverage includes both, but the exam point is the disproportionate frequency of Salmonella in these children.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.