Infectious mononucleosis is the great imposter and can mimic many other diseases. Infectious Mononucleosis is caused by the Epstein-Barr virus, which generally produces minimal symptoms in children until adolescence.

“This infection can be asymptomatic or result in a mild illness that may be indistinguishable from other childhood illnesses,” says Rachel C. Orscheln, MD, infectious disease physician at St. Louis Children’s Hospital. “When the infection occurs in adolescents, it results in mononucleosis 30 to 35 percent of the time.”

What are the symptoms of Infectious Mononucleosis?

Symptoms develop within 4 to 6 weeks after being exposed to Infectious Mononucleosis.

The symptoms usually end within 1 to 2 months. Each person may experience symptoms differently. Symptoms may include:

  • Fever
  • Sore throat
  • Swollen lymph glands, especially in neck
  • Fatigue
  • Sometimes, swollen spleen or liver may develop
  • Heart and brain involvement occur only rarely, and Infectious Mononucleosis is almost never fatal.

Once a person has had this virus, there is usually no risk for developing it again.

How is Infectious Mononucleosis diagnosed?

A medical history, physical exam and reported symptoms are important ways a health professional diagnoses Infectious Mononucleosis. Blood tests are needed to confirm the diagnosis.

What is the treatment for Infectious Mononucleosis?

No specific treatment exists for Infectious Mononucleosis, other than treating the symptoms.

  • Take Acetaminophen or Ibuprofen for fever and sore throat.
  • Gargle with warm salt water or use lozenges for relief of sore throat in older children.
  • Get plenty of rest.
  • Follow your doctor’s advice regarding activity level because the spleen may be enlarged with Infectious Mononucleosis, and activities are limited to decrease the risk of rupturing the spleen.
  • Drink plenty of fluids to prevent dehydration.

How is Infectious Mononucleosis spread?

Infectious Mononucleosis is often spread by intimate contact with infected saliva from the mouth. Rarely, is this virus spread through the air or blood. People with Infectious Mononucleosis may be able to spread the infection to others for a period of weeks. The Center for Disease Control (CDC) does not recommend any special precautions or isolation, since the virus is also found in the saliva of healthy people.

This article was written by Sandra Chinnici, RN, an Answer Line nurse at St. Louis Children’s Hospital. For more information about Infectious Mononucleosis, contact our Center for Families Resource Library.


Expert Advice