From the Guidelines
Symptoms of a lung abscess in an infant with a history of MSSA pneumonia include persistent fever despite antibiotics, respiratory distress, cough, decreased appetite, irritability, and lethargy, and yes, Methicillin-Sensitive Staphylococcus Aureus (MSSA) can definitely cause lung abscesses. Physical examination may reveal decreased breath sounds over the affected area, and the infant might have purulent sputum or abnormal lung sounds.
Clinical Presentation
The clinical presentation of a lung abscess in an infant with a history of MSSA pneumonia can be severe and may require hospitalization. According to the guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America 1, infants with pneumonia caused by CA-MRSA, such as MSSA, have a high incidence of necrotizing pneumonia and frequently require ICU admission.
Diagnosis and Treatment
Diagnosis of a lung abscess typically involves chest imaging, such as an X-ray or CT scan, which can show a cavity with an air-fluid level or a consolidated area with central necrosis 1. Complete blood count typically shows elevated white blood cells, and blood cultures may be positive for MSSA. Treatment of MSSA lung abscesses typically requires prolonged antibiotic therapy, usually 2-6 weeks depending on clinical response, with initial treatment often including intravenous antibiotics such as nafcillin or oxacillin (100-150 mg/kg/day divided every 6 hours), followed by oral antibiotics like cephalexin (25-50 mg/kg/day divided every 6-8 hours) once clinical improvement occurs 1.
Complications and Monitoring
Close monitoring for complications such as empyema, pneumothorax, or sepsis is crucial during treatment. The guidelines recommend that children with nonresponding CAP should have the clinical severity of their condition repeatedly assessed to determine whether they require higher levels of care, and that children with complications of pneumonia, including moderate to large pleural effusions, require consultation with those services in the institution that have expertise in obtaining pleural fluid specimens and providing drainage, fibrinolytic agents, and/or VATS 1.
Pathophysiology
The pathophysiology of lung abscess formation involves bacterial invasion causing tissue necrosis and liquefaction, leading to cavity formation filled with purulent material. MSSA is a common bacterial pathogen capable of tissue destruction and abscess formation, and its ability to cause lung abscesses is well-documented 1.
Management
Management of lung abscesses in infants with a history of MSSA pneumonia requires a comprehensive approach, including prolonged antibiotic therapy, close monitoring for complications, and consultation with specialists as needed. The guidelines emphasize the importance of individualized treatment and the need for close monitoring of the child's clinical response to therapy 1.
From the FDA Drug Label
Lower respiratory tract infections including pneumonia, empyema, and lung abscess caused by anaerobes, Streptococcus pneumoniae, other streptococci (except E. faecalis), and Staphylococcus aureus Skin and skin structure infections caused by Streptococcus pyogenes, Staphylococcus aureus, and anaerobes. The symptoms of lung abscess in an infant are not directly stated in the label. Key points about the causative organisms are:
- Staphylococcus aureus can cause lung abscess.
- The label does not provide information on the symptoms of lung abscess in infants with a history of pneumonia infections caused by Methicillin-Sensitive Staphylococcus aureus (MSSA) 2.
From the Research
Symptoms of Lung Abscess in Infants
- The symptoms of lung abscess in infants are not explicitly stated in the provided studies, but it can be inferred that they may include symptoms of pneumonia, such as cough, fever, and difficulty breathing 3, 4.
- Lung abscess is a cavity with a well-defined wall that develops in the lung due to microbial infection, and it may be related to necrotizing pneumonia from aerobic organisms, such as Staphylococcus aureus 5.
- In infants and children, lung abscesses are often solitary and may be located in the right lower lobe or other lobes of the lung 6.
MSSA as a Cause of Abscesses
- Methicillin-Sensitive Staphylococcus aureus (MSSA) can cause lung abscesses, as it is an aerobic organism that can lead to necrotizing pneumonia 5, 4.
- MSSA is a common cause of pneumonia and other respiratory infections in children, and it can lead to complications such as lung abscess and empyema 3, 4.
- The treatment of lung abscesses caused by MSSA typically involves prolonged antibiotic therapy, and surgical drainage may be necessary in some cases 6, 4.