An Unusual Presentation of Community-Acquired Methicillin-Resistant Staphylococcus aureus Infection in a Child Treated With Linezolid.

Methicillin-resistant Staphylococcus aureus (MRSA) infection is a major public health concern. MRSA isolates are classified into community-acquired MRSA (CA-MRSA) and healthcare-associated MRSA based on their epidemiology, antibiotic susceptibility patterns, and molecular characteristics. CA-MRSA typically causes skin and soft tissue infections. However, the incidence of invasive infections has increased in recent years. This paper describes the case of a 12-year-old girl with an unusual presentation of CA-MRSA. The patient presented with right thigh pyomyositis complicated by deep vein thrombosis, septic pulmonary embolism, and necrotizing pneumonia. The MRSA isolate was susceptible to vancomycin but resistant to the other anti-MRSA antibiotics. The patient was successfully treated with linezolid after clinical deterioration with vancomycin. A literature review comparing vancomycin and linezolid in invasive MRSA infections among children indicated that linezolid has better lung and tissue penetration than vancomycin, and an early switch is warranted in the case of deterioration after vancomycin administration and the lack of other alternatives.