Which pairing correctly matches age group with the most common bacterial cause of orbital cellulitis?

Which pairing correctly matches age group with the most common bacterial cause of orbital cellulitis?

• A. Adults: Haemophilus influenzae; Children: Staph aureus
• B. Adults: Staphylococcus aureus; Children: Haemophilus influenzae
• C. Adults: Streptococcus pneumoniae; Children: Pseudomonas aeruginosa
• D. Adults: Pseudomonas aeruginosa; Children: Streptococcus pneumoniae

Answer: (B)

Age-related differences in the bacterial causes of orbital cellulitis explain why this pairing fits. In adults, Staphylococcus aureus is the most common culprit, reflecting the prominence of skin and soft tissue flora and patterns of sinus-related spread. In children, Haemophilus influenzae historically dominates the etiologic spectrum due to nasopharyngeal colonization and the ease of spread from the sinuses to the orbit. Vaccination has changed the exact proportions, but the traditional teaching aligns with this pairing: adults with Staphylococcus aureus and children with Haemophilus influenzae. Other organisms can occur, but they don’t define the age-specific pattern as clearly.

Age-related differences in the bacterial causes of orbital cellulitis explain why this pairing fits. In adults, Staphylococcus aureus is the most common culprit, reflecting the prominence of skin and soft tissue flora and patterns of sinus-related spread. In children, Haemophilus influenzae historically dominates the etiologic spectrum due to nasopharyngeal colonization and the ease of spread from the sinuses to the orbit. Vaccination has changed the exact proportions, but the traditional teaching aligns with this pairing: adults with Staphylococcus aureus and children with Haemophilus influenzae. Other organisms can occur, but they don’t define the age-specific pattern as clearly.