Mycoplasma pneumonia

Definition

Mycoplasma pneumonia is an infection of the lungs caused by Mycoplasma pneumoniae.

Causes, incidence, and risk factors

Pneumonia is a common illness, affecting 1 in 100 people annually. It is caused by many different types of bacteria, viruses, and other infectious organisms. Each year an estimated 2 million cases occur in the United States. Most cases of pneumonia are mild and easily treated, while some cases are more serious and may result in severe illness and even death.

M. pneumoniae is a common cause of mild pneumonia and usually affects people younger than 40. Various studies suggest that it causes 15-50% of all pneumonia in adults and an even higher percentage of pneumonia in school-aged children.

People at highest risk for mycoplasma pneumonia include those living or working in crowded areas such as schools and homeless shelters, although many people who contract mycoplasma pneumonia have no identifiable risk factor.

Symptoms

The symptoms are generally mild and appear over a period of one to three weeks. They may progress to more severe symptoms in some people.

Common symptoms include the following:

• headache
  
• Fever (may be high)
  
• Chills
  
• Excessive sweating
  
• Cough
  o Usually dry
  o Usually without phlegm or blood
  
• Chest pain
  
• Sore throat
  

Less frequently seen symptoms include the following:

• Skin lesions or rash
  
• Eye pain or soreness
  
• Muscle aches and joint stiffness
  
• Neck lump
  
• Rapid respiratory rate
  
• Ear pain
  

Signs and tests
A physical examination may reveal enlarged Lymph nodes and inflammation of the eardrum. An examination of the chest with a stethoscope (auscultation) reveals crackles.

These tests help confirm the diagnosis:

• Blood tests for antibodies to mycoplasma
  
• Sputum culture
  
• Chest x-ray