Clinical Features of Mycoplasma pneumoniae Infection

Key points

  • Mycoplasma pneumoniae infections have a wide spectrum of clinical symptoms, including extrapulmonary manifestations.
  • Most of these infections are self-limiting, but serious and life-threatening complications can occur.
A healthcare provider listens to the lungs of a young girl.

Clinical presentation

Common manifestations include:

  • Pharyngitis
  • Pneumonia
  • Tracheobronchitis

Common signs and symptoms

Tracheobronchitis symptoms

Common symptoms include:

  • Cough
  • Fever
  • Headache
  • Malaise

Illness onset can be gradual and subacute, slowly progressing to a higher fever and persistent cough.

Pneumonia symptoms

M. pneumoniae pneumonia is often referred to as "walking pneumonia".

In addition to tracheobronchitis symptoms, pneumonia symptoms can include mild dyspnea. While the cough is initially dry, it may later produce moderate amounts of non-bloody sputum.

Chest auscultation may show scattered or localized rhonchi and expiratory wheezes. Chest radiograph often shows unilateral or bilateral bronchopneumonia.

Younger patients may have different symptoms

Infections in children younger than 5 years of age may run subclinical, be mild, and not result in pneumonia.

These infections are often characterized by:

  • Coryza without concomitant fever
  • Diarrhea
  • Vomiting
  • Wheezing

Prolonged clinical course possible

The disease can persist for months; however, it's frequently mild and self-resolving.

Complications

Severe complications are uncommon but can result in hospitalization and sometimes death.

Complications involving the respiratory system include exacerbation of asthma and severe pneumonia.

Other complications include:

  • Encephalitis
  • Gastrointestinal complaints
  • Hemolytic anemia
  • Nonspecific myalgias, arthralgias, or polyarthropathies
  • Renal dysfunction
  • Septic arthritis
  • Skin disorders

Skin disorders can include

  • Erythema multiforme
  • Mycoplasma-induced rash and mucositis
  • Stevens-Johnson syndrome
  • Toxic epidermal necrolysis