Day: February 25, 2008

How Do Mycoplasma pneumoniae Infections Present?

Patient Presentation
A 17-year-old female came to clinic with severe left ear pain for 1 day.
She had had a low grade fever, cough and rhinorrhea for about 1 week.
The cough was worsening but was not productive. Her throat was also sore for 3 days.
Several of her friends had strep throat and another had pneumonia.
The past medical history was non-contributory.
The review of systems was negative including no rashes.
The pertinent physical exam showed a teenage female who was in some pain. Her temperature was 38.5° C and respiratory rate was 38 but with no respiratory distress.
Her pharynx was erythematous without exudate. Her left tympanic membrane had blood behind it with distorted landmarks and no mobility. Her right tympanic membrane had opaque fluid behind it and little mobility.
There was moderate clear to yellow rhinorrhea. She had shoddy anterior cervical lymph nodes. Her lungs had scattered rales bilaterally and mild end expiratory wheezing.
The rest of her examination was negative.
The laboratory evaluation included a rapid strep test that was negative.
The diagnosis of hemorrhagic myringitis and community-acquired pneumonia was made with Mycoplasma pneumoniae as the probably etiology. It was known that mycoplasma was spreading throughout the community.
She was begun on azithromycin and pain relievers. She was counseled about signs and symptoms to monitor and call about. She was also counseled about ways to try to decrease the spread to other persons.

Discussion
Mycoplasma pneumoniae is a common infection in children and adults. It is spread through respiratory droplets from person to person and the incubation period is ~3 weeks.
Mycoplasma pneumoniae causes ~20% of pneumonias in middle/high school children and up to 50% in college students. It is highly contagious and immunity is not long lasting.

Titres rise 7-9 days after infection and peak at 3-4 weeks. Positive testing is defined as a 4x or more rise in the titre (IgM, IgG) with paired sera or a single titre of greater or equal to 1:32.
Antigen and polymerase chain reaction testing can also be performed and are generally more sensitive.

Treatment for mycoplasma is usually with macrolide antibiotics such as erythromycin (30-40 mg/kg/day divided in 4 doses/day for 10 days), azithromycin (10 mg/kg on day one, 5 mg/kg on days 2-5 for a total of 5 days, each dose given once daily) and clarithromycin (15 mg/kg/day divided in 2 doses/day for 10 days).
Supportive and specific treatments for different problems may be required such as steroid treatment for hematological or neurological problems.
Prophylactic antibiotics for close contacts are usually not recommended.

Learning Point
Mycoplasma pneumoniae presents clinically in many different ways. The prodrome is usually gradual with malaise, low grade fever, chills and headache.
Presentations include:

  • Asymptomatic
    • Respiratory (may have a constellation of findings)
      • Cough – non-productive
      • Pharyngitis
      • Pneumonia
      • Otalgia – bullous myringitis, hemorrhagic myringitis
      • Rhinorrhea
      • Sinusitis – often asymptomatic and coexistent with pneumonia
      • Wheezing – may worsen asthma symptoms
    • Cardiac
      • Conduction abnormalities on electrocardiogram
      • Congestive heart failure
      • Chest pain
      • Myocarditis
      • Pericarditis
      • Rhythm abnormalities
    • Dermatologic
      • Rash – highly variable from mild macular-papular to vesicular to Stevens-Johnson syndrome. It is commonly seen associated with respiratory symptoms and may be worsened by some antibiotics
    • Hematologic
      • Anemia secondary to hemolysis – due to cold agglutinin antibody production
    • Nephrologic
      • Glomerulonephritis
    • Neurologic – occurs in 0.1 % of patients, but may have significant morbidity and mortality
      • Cerebellar ataxia
      • Cranial nerve palsies
      • Aseptic meningitis
      • Meningoencephalitis
      • Peripheral neuropathy
      • Transverse myelitis
    • Gastrointestinal
      • Abdominal pain, generalized
      • Pancreatitis
    • Rheumatologic
      • Arthritis – often polyarthritis
      • Myositis

    Questions for Further Discussion
    1. What are typical findings on chest radiograph for mycoplasma?
    2. What are typical findings on the complete blood count for mycoplasma?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Pneumonia

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Hammerschlag MR. Mycoplasma pneumoniae infections.
    Curr Opin Infect Dis. 2001;14(2):181-6.

    American Academy of Pediatrics. Mycoplasma pneumoniae Infections, In Pickering LD, Baker CJ, Long SS, McMillan JA, eds. Red Book: 2006 Report of the Committee on Infectious Diseases. 27th edit. Elk Grove Village, IL: American Academy of Pediatrics; 2006;468-470.

    Zaleznik DF, Vallejo JS. Mycoplasma pneumoniae infection in children. UpToDate. Available from the Internet at http://www.uptodate.com/(rev. 8/1/2007, cited 1/17/08)

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    8. Health care services aimed at preventing health problems or maintaining health are provided.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

    Date
    February 25, 2008