Can Mycoplasma pneumoniae present with diarrhea?

Mycoplasma Pneumoniae Can Present with Diarrhea

Yes, Mycoplasma pneumoniae infection can present with diarrhea as an extrapulmonary manifestation, though it is not among the most common symptoms. 1

Clinical Presentation of Mycoplasma Pneumoniae

Typical Respiratory Manifestations

• The classic presentation of Mycoplasma pneumoniae infection includes fever, headache, arthralgia, and cough 2
• Physical examination typically reveals crackles on auscultation, and approximately 30% of patients may present with wheezing 2
• Chest pain can occur, particularly in older children and adults 2

Extrapulmonary Manifestations

• Mycoplasma pneumoniae can cause a wide range of extrapulmonary manifestations affecting multiple organ systems 3
• Gastrointestinal symptoms including diarrhea and abdominal pain can occur as part of the clinical presentation 1
• In some cases, diarrhea may even be the presenting symptom before respiratory symptoms develop 1
• A case report documented a patient who was initially admitted to the hospital with diarrhea, abdominal pain, and fever, later diagnosed with Mycoplasma pneumoniae infection 1

Other Extrapulmonary Manifestations

• Neurological complications (encephalitis, meningitis, Guillain-Barré syndrome)
• Dermatologic manifestations (rashes, Stevens-Johnson syndrome)
• Cardiac involvement (myocarditis, pericarditis)
• Hematologic abnormalities
• Renal complications 3, 4

Diagnostic Considerations

When to Suspect Mycoplasma in Patients with Diarrhea

• Consider Mycoplasma pneumoniae in patients with diarrhea who also have:
  • Concurrent respiratory symptoms (especially dry cough) 2
  • Fever that persists despite treatment with beta-lactam antibiotics 5
  • Epidemiologic context (school-aged children, outbreak settings) 2
  • Other extrapulmonary manifestations such as skin rashes or joint pain 3

Diagnostic Testing

• Paired serology showing a ≥4-fold rise in IgG titer is considered diagnostic 1
• PCR testing of respiratory specimens offers rapid diagnosis 6
• Culture is technically challenging and not routinely performed 6

Treatment Approach

Antibiotic Therapy

• Macrolides (azithromycin, clarithromycin) are the first-line treatment for Mycoplasma pneumoniae infections 2
• For patients with severe manifestations or in areas with high macrolide resistance, consider:
  • Fluoroquinolones (in adults)
  • Tetracyclines (doxycycline in children >8 years and adults) 3

Management of Gastrointestinal Symptoms

• Supportive care with adequate hydration 2
• Antipyretics for fever control 2
• In severe cases with systemic vasculitis or significant extrapulmonary manifestations, corticosteroids may be considered 1

Clinical Pearls and Pitfalls

Important Considerations

• Diarrhea alone is rarely the only manifestation of Mycoplasma pneumoniae infection; look for associated respiratory symptoms 2, 1
• Mycoplasma pneumoniae should be considered in the differential diagnosis when patients present with both respiratory and gastrointestinal symptoms that do not respond to standard treatments 1
• The severity of disease appears related to the host immune response rather than direct bacterial invasion 3

Common Pitfalls

• Failing to consider Mycoplasma pneumoniae in patients with predominant gastrointestinal symptoms 1
• Treating with beta-lactam antibiotics, which are ineffective against Mycoplasma (lacks cell wall) 3
• Missing the diagnosis in patients without typical respiratory symptoms 1

Mycoplasma pneumoniae infections can present with a wide spectrum of clinical manifestations beyond the respiratory tract, including gastrointestinal symptoms such as diarrhea. Recognizing these extrapulmonary manifestations is crucial for appropriate diagnosis and treatment.