Atypical pneumonia is a type of pneumonia caused by bacteria other than the Streptococcus pneumoniae bacteria, which is the most common cause of pneumonia. Atypical pneumonia is also known as walking pneumonia, because those affected usually don't experience severe symptoms and can often carry on with their daily lives.
Mycoplasma pneumonia is the most common type of atypical pneumonia, accounting for approximately 15% of all pneumonia cases. It is caused by the Mycoplasma pneumoniae bacterium and is most common among teenagers and young adults. Symptoms of Mycoplasma pneumonia include dry cough, fever, headache, muscle aches, chest pain, and fatigue. Other atypical pneumonia types include Chlamydophila pneumoniae (previously known as Chlamydia pneumoniae) and Legionella pneumonia.
Chlamydophila pneumonia can cause similar symptoms to Mycoplasma pneumonia, and occasionally can cause a severe form of pneumonia known as severe acute respiratory syndrome (SARS). Legionella pneumonia is caused by the Legionella bacteria and can cause severe symptoms, including high fever, chills, and difficulty breathing.
Atypical pneumonias can be treated with antibiotics, although the type of antibiotic used depends on the causative organism. Common antibiotics used to treat atypical pneumonias include macrolides (such as azithromycin and clarithromycin) and tetracyclines (such as doxycycline). It is important to finish the full course of antibiotics prescribed by your doctor in order to ensure the infection is completely eradicated.