Mycoplasma Pneumonia (Walking Pneumonia)

What Mycoplasma pneumoniae is

Mycoplasma pneumoniae is one of the smallest bacteria. It has no cell wall, which is why penicillins and cephalosporins (which attack cell walls) do not work against it. It attaches to the lining of the airways, damaging the tiny hairs (cilia) that clear mucus, which explains the long-lasting cough.

Infections occur year-round, with larger outbreaks every few years. Many infections cause only a cold-like illness or bronchitis. Only a minority, about 1 in 10 or fewer, develop pneumonia.

Symptoms

Symptoms come on gradually over several days:

• persistent, often dry, hacking cough, which can last 3 to 6 weeks
• sore throat
• headache
• tiredness and malaise
• low-grade fever and chills
• ear pain
• chest soreness from coughing
• wheezing, especially in children with asthma

Young children under 5 may have cold-like symptoms, with sneezing, runny nose and sometimes wheezing, rather than classic pneumonia, though recent outbreaks have shown more pneumonia in young children than previously recognized.

Why "walking pneumonia"?

People often feel ill enough to be tired and cough a lot, but not so ill that they need bed rest or hospital care. The chest X-ray often looks worse than the person appears.

Mycoplasma vs typical pneumonia

How it spreads

Mycoplasma spreads through respiratory droplets when an infected person coughs or sneezes. It spreads most easily in close contact: households, schools, dormitories and military barracks. The incubation period is 1 to 4 weeks, so outbreaks build slowly. People can be contagious for several weeks.

Complications

Most people recover without problems. Uncommon complications include:

• asthma attacks and new wheezing
• ear infections and sinusitis
• mycoplasma-induced rash and mucositis (MIRM) and Stevens-Johnson syndrome: painful sores of the mouth, eyes and genitals, mainly in children and teens
• erythema multiforme and other rashes
• hemolytic anemia caused by cold agglutinin antibodies
• encephalitis, Guillain-Barré syndrome and other nervous system problems (rare)
• severe pneumonia in people with sickle cell disease, weakened immunity or lung disease

Diagnosis

Many cases are diagnosed based on symptoms. Tests are used when confirmation matters:

• chest X-ray if pneumonia is suspected: often shows patchy changes in both lungs
• PCR test on a throat or nose swab, the preferred test, often part of a respiratory panel
• blood antibody tests, less useful for quick decisions
• pulse oximetry to check oxygen levels

Treatment

Antibiotics

• Macrolides (azithromycin, clarithromycin) are first-line for children.
• Doxycycline is an alternative for adults and older children, and in some cases younger children.
• Fluoroquinolones (levofloxacin, moxifloxacin) for adults.
• Macrolide resistance is common in parts of Asia and occurs in the US. If symptoms do not improve after 48 to 72 hours, a doctor may switch antibiotics.
• Antibiotics are not usually needed for mild upper respiratory infection or bronchitis from mycoplasma, which usually clears on its own.

Home care

• rest and plenty of fluids
• acetaminophen (paracetamol) or ibuprofen for fever and aches. Follow the label dose. No aspirin for children or teenagers
• honey in warm drinks for cough (not for babies under 12 months)
• a humidifier or steamy shower to ease cough
• cough medicines are not recommended for children under 6

Hospital care

Hospital treatment is needed for low oxygen levels, severe breathing difficulty, dehydration or serious complications, and may include oxygen, IV antibiotics and, for severe inflammatory complications, steroids.

Recovery

Fever and fatigue usually improve within 1 to 2 weeks. The cough often lingers for 3 to 6 weeks as the airways heal. A cough that lasts longer, or symptoms that worsen, should be reviewed.

Prevention

There is no vaccine. To reduce spread:

• wash hands often
• cover coughs and sneezes
• stay home when sick, especially with fever
• avoid close contact with people who are ill

Frequently asked questions

What are the symptoms of mycoplasma pneumonia?

Symptoms develop gradually and include a persistent, often dry cough, sore throat, headache, tiredness and low-grade fever. The cough can last for weeks. Young children may have cold-like symptoms or wheezing.

Is walking pneumonia contagious?

Yes. It spreads through respiratory droplets from coughs and sneezes, especially in households, schools and dormitories. Symptoms appear 1 to 4 weeks after exposure, and people can remain contagious for several weeks.

How long does mycoplasma pneumonia last?

Fever and tiredness usually improve within 1 to 2 weeks, especially with antibiotics. The cough commonly lasts 3 to 6 weeks while the airways heal. Most people recover fully.

Why doesn't amoxicillin work for mycoplasma?

Mycoplasma bacteria have no cell wall, and amoxicillin works by attacking bacterial cell walls. Antibiotics that block bacterial protein production, such as azithromycin or doxycycline, are effective instead.

Do you need antibiotics for walking pneumonia?

Antibiotics are recommended when mycoplasma causes pneumonia, as they shorten illness. Mild infections that cause only cold-like symptoms or bronchitis often clear on their own. A doctor will decide based on symptoms, age and exam.