The mainstay of treatment for atypical pneumonia is antibiotic therapy. In mild cases, treatment with oral antibiotics at home may be appropriate. Severe cases (especially common with pneumonia, due to Legionella) may require intravenous antibiotics and oxygen supplementation.

Antibiotics with activity against these organisms include -- erythromycin, azithromycin, clarithromycin, fluoroquinolones and their derivatives (e.g., levofloxacin), and tetracyclines (e.g., doxycycline).

Most patients with pneumonia due to Mycoplasma or Chlamydia do well with appropriate antibiotic therapy, although there is a small chance of relapse if antibiotics are used for too short a period of time (less than two weeks).

In the case of pneumonia due to Legionella, severe illness occurs particularly among the elderly and those individuals with chronic diseases and weakened immune systems. It is associated with a higher mortality rate.

• Respiratory failure, mechanical ventilation -- especially in severe forms of pneumonia due to Legionella
• Rash and hemolytic anemia -- especially associated with pneumonia due to Mycoplasma

Seek medical evaluation if you develop fevers, cough, and/or shortness of breath. While there are numerous causes for these symptoms, you will need to be evaluated for pneumonia.