Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

Mononucleosis

(Infectious Mononucleosis; Mono)
by Rick Alan
Definition

Mononucleosis is a viral disease characterized by fever, sore throat, swollen lymph glands, and fatigue.

Causes

Mononucleosis is usually caused by the Epstein-Barr virus (EBV). While other viruses can cause mono-like symptoms, EBV is generally thought to be the virus which causes mononucleosis. Found mainly in saliva and mucus, EBV is passed most efficiently from person-to-person by intimate behavior, such as kissing.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Many people contract EBV during their lifetime. Risk factors that increase the likelihood that EBV will develop into mononucleosis include:

  • Contracting EBV after the age of 10
  • Living in close quarters with a large number of people, such as in a college dormitory
  • Lowered immune resistance, due to other illness, stress, or fatigue

One episode of mononucleosis usually produces permanent immunity.

Symptoms

Signs of mononucleosis usually begin about 4-7 weeks after you were exposed to the virus. The initial symptoms may be a sense of general malaise that lasts about a week. This is followed by a set of signs and symptoms that may include:

  • Mild jaundice
  • Enlargement of the spleen
  • Fatigue
  • High fever
  • Loss of appetite
  • Muscle aches
  • Severely sore throat
  • Swelling of the lymph nodes
  • Swollen tonsils
Diagnosis

Your doctor will ask about your symptoms and medical history, and perform a physical exam. Diagnosis is based on:

  • Four primary symptoms:
  • Two primary tests:
    • Throat culture (to check for strep throat , which can complicate mono)
    • Blood tests and "mono spot" tests
  • Your age
Treatment

There is no treatment to cure mononucleosis or to shorten the length of illness. It usually runs its course in 4-6 weeks, although the fatigue may linger.

During the first few weeks after diagnosis, patients should avoid contact sports. Inflammation of the spleen from mononucleosis puts individuals at a high risk of splenic rupture. Rupture can require surgery, and in rare cases, it can be fatal.

Treatment includes:

Relief of Symptoms
  • Taking nonprescription pain relievers to lessen aches and pains and control fever
    • Avoid aspirin , especially in children.
  • Gargling with warm, salty water to relieve sore throat

Steroids are sometimes used if the swelling in the throat is interfering with breathing, or if a complication involving low platelet counts or anemia occurs. This treatment has not been shown to be helpful in mild cases.

Comfort
  • No heavy lifting or exercise for at least several weeks after recovery (This decreases the risk of rupturing an enlarged spleen that may have developed as part of this illness.)
  • Rest and fluids

If you are diagnosed with mononucleosis, follow your doctor's instructions .

Prevention

Most people contract the EBV virus sometime during their lives. Prevention is geared toward decreasing the likelihood that EBV will develop into mononucleosis. Follow these guidelines to decrease your risk:

  • Eat a healthful diet .
  • Avoid excess stress.
  • Avoid intimate contact (especially kissing) with anyone who has active mononucleosis.
  • Get enough rest.

Last reviewed: September 2011 by Lawrence Frisch, MD, MPH.

RESOURCES:
CANADIAN RESOURCES:
References:
  • Academy of Family Physicians website. Available at: http://www.aafp.org/online/en/home.html . Accessed July 17, 2009.
  • Balfour HH Jr, Hokanson KM, Schacherer RM, et al. A virologic pilot study of valacyclovir in infectious mononucleosis. J Clin Virol . 2007;39:16-21.
  • Berkow R. The Merck Manual of Medical Information . 17 ed. New York, NY: Simon and Schuster, Inc; 2000.
  • Luzuriaga K, Sullivan JL. Infectious mononucleosis. N Engl J Med . 2010 May 27;362(21):1993-2000.
  • Mononucleosis. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/mononucleosis/DS00352/DSECTION=causes . Updated June 2009. Accessed July 17, 2009.