Mycoplasma Pneumonia in Children

It’s been a BIG year for Mycoplasma! If your EDs have been anything like ours, you’ve been seeing more patients with Mycoplasma Pneumonia than you expected. Many kids are presenting to the ED for failure of outpatient antibiotic therapy of community acquired pneumonia, only to find out that’s because they weren’t on the right meds! Let’s debrief on this atypical bug. 

Mycoplasma Pneumonia: What is it? 

• Mycoplasma pneumoniae is a small, obligate intracellular bacterium that is unique in that it lacks a cell wall. 
• Why is this important? Because it means they are resistant to antibiotics that target cell wall synthesis (e.g., penicillins, cephalosporins) – hence, those bounce backs we are seeing! 
• Transmission is via spread of respiratory droplets, and is common in crowded settings like schools/daycare center.
• The bacterium binds to epithelial cells of the upper respiratory tract/lower airways and causes an immune response including inflammation, leading to mucosal damage, increased mucus production, and impaired gas exchange.

Mycoplasma Pneumonia: Epidemiology

• According to the CDC, infections from Mycoplasma pneumnoniae have increased in the US, especially in young children.
• After a prolonged period of low incidence, M. pneumoniae re-emgerged in 2023 after the COVID pandemic. From March – October of this year (2024), there’s been an increase in infections among all age groups but highest among children.
• Historically, these infections most often occurred among children ages 5-17 years and young adults. 
• However, this year we have seen a percentage increase in M. pneumoniae discharge diagnosis from 1.0% to 7.2% among children age 2-4 years. This is notable because historically, M. pneumoniae hasn’t been recognized as a leading cause of pneumonia in this age group! 

Mycoplasma Pneumonia: Clinical Features

• Incubation period: typically 2-3 weeks
• Usual symptoms include fever, persistent, dry, non-productive cough, fatigue, malaise and chest discomfort
• The cough can persist for weeks to months
• Patient’s can develop severe infection with complications such as respiratory failure, pleural effusions, empyema, and necrotizing pneumonia.

Keep in mind, there can be extrapulmonary manifestations as well! These include:

• Mucocutaneous disease including rashes like erythema multiforme, mycoplasma induced rash and mucositis (AKA reactive infectious mucocutaneous eruption RIME), and SJS.
• Joint pain
• Hemolytic anemia due to the presence of IgM antibodies on RBCs causing autoimmune hemolysis
• Rarely neurological complications such as meningoencephalitis, seizures, transverse myelitis, GBS, and cerebellar ataxia. 

Mycoplasma Pneumonia: Diagnosis

• Often a clinical diagnosis when presentation is suggestive of mycoplasma infection (see above); however, it can be confirmed on laboratory testing. 
• Throat/NP swabs can be sent for PCR testing, which is highly sensitive and specific for M. pneumoniae DNA. 
• Can detect IgM and IgG antibodies to diagnose current or recent infection, however this may take longer to result.
• Chest X-rays will often show bilateral, patchy infiltrates and are less localized compared to typical bacterial pneumonia. Findings, however, are variable, non-specific, and studies have shown plenty of confirmed cases by PCR with unilateral, lobar consolidations.

Mycoplasma Pneumonia: Management

• Symptomatic care is important! Treat that fever. Cough suppressive are generally ineffective and not approved in many ages. 
• Empiric antibiotic therapy for known/suspected M. pneumoniae infection would include a macrolide, tetracycline, or fluoroquinolone antibiotic
  • For immunocompetent children, first line would be a macrolide like azithromycin. If there is a shortage, a tetracycline is appropriate.
  • In the immunocompromised patient, fluoroquinolone like levofloxacin are a good choice for initial antibiotic. 

Moral of the Morsel: 

• These are Atypical Times! Mycoplasma is back with a vengeance, including in that 2-4 year age group! 
• Antibiotic Failure? Maybe we didn’t pick the right target? Don’t forget about M. pneumoniae as an etiology of CAP, especially if they are failing on a beta-lactam antibiotic. 
• “Z-pack” is not a dirty word. First line therapy will generally be your macrolide antibiotic, but could also consider tetracycline or fluoroquinolone depending on the patient.

Resources: 

“Mycoplasma Pneumoniae Infections Have Been Increasing.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 18 Oct. 2024, www.cdc.gov/ncird/whats-new/mycoplasma-pneumoniae-infections-have-been-increasing.html.

Gao, Li, and Yanhong Sun. “Laboratory Diagnosis and Treatment of Mycoplasma Pneumoniae Infection in Children: A Review.” Annals of Medicine, U.S. National Library of Medicine, Dec. 2024, pmc.ncbi.nlm.nih.gov/articles/PMC11299444/.

Vallejo, Jesus G. “Mycoplasma Pneumoniae Infection in Children.” UpToDate, 1 Nov. 2024, www.uptodate.com/contents/mycoplasma-pneumoniae-infection-in-children.