Rare and unexpected cause for retropharyngeal abscess in an immunocompetent man: metastatic community-acquired methicillin-resistant Staphylococcus aureus infection.

Staphylococcus aureus causes clinical diseases ranging from mild skin infections to devastating conditions such as septic shock, endocarditis and osteomyelitis. S. aureus is a common cause of community-acquired bacteraemia. Prolonged bacteraemia may cause metastatic infection, manifesting as endocarditis, osteomyelitis and abscesses. A man in his 20s presented with a short-duration of fever and odynophagia. CT of the neck suggested a retropharyngeal abscess. Retropharyngeal abscesses are typically polymicrobial and caused by resident oral cavity flora. In the hospital, he developed shortness of breath and hypoxia. CT of the chest showed peripheral, subpleural nodular opacities raising suspicion for septic pulmonary emboli. Blood cultures demonstrated the growth of methicillin-resistant S. aureus The patient completely recovered with antibiotic therapy alone. This is a unique and rare presentation case of metastatic S. aureus bacteraemia, manifesting as a retropharyngeal abscess without any evidence of infective endocarditis on transoesophageal echocardiography.