Mycoplasma Pneumoniae

Question 1

Mycoplasma pneumoniae is an atypical cause of pneumonia, what patients are usually affected?

Question 2

What are the features of mycoplasma pneumoniae?

Answer 2

• The disease typically has a prolonged and gradual onset
• Flu-like symptoms classically precede a dry cough
• Bilateral consolidation on x-ray
• Complications may occur as below.

Question 3

What are some complications of mycoplasma pneumoniae?

Answer 3

• Cold agglutins (IgM) may cause an haemolytic anaemia, thrombocytopenia
• Erythema multiforme, erythema nodosum
• Meningoencephalitis, Guillain-Barre syndrome
• Bullous myringitis: painful vesicles on the tympanic membrane
• Pericarditis/myocarditis
• Gastrointestinal: hepatitis, pancreatitis
• Renal: acute glomerulonephritis

Question 4

What investigations should be done if you suspect mycoplasma pneumoniae?

Answer 4

• Diagnosis is generally by Mycoplasma serology
• Positive cold agglutination test

Question 5

What are the similarities and differences between Legionella and Mycoplasma Pneumoniae?

Answer 5

Similarities:

• They are both atypical pneumonias with flu like symptoms that have a dry cough.
• They are both treated with macrolides.
• They both can produce deranged LFTs.

Differences:

• Legionella
  
  • Lymphopenia
  • Hyponatraemia
  • Diagnosed using urinary antigens.
• Mycoplasma
  
  • Haemolytic anaemia/ ITP
  • Erythema multiforme
  • Encephalitis/ GBS
  • Peri/Myocarditits
  • Diagnosed using serology