Infectious mononucleosis

Infectious mononucleosis, also known as mono or kissing disease, is a viral infection.

The symptoms of mononucleosis can vary, but will typically include fever, intense fatigue, severe throat pain, and swollen lymph nodes (small, sensitive bumps) in the neck.

In about half of cases, the spleen - an organ located just below the left rib cage - becomes enlarged . Rarely, the swelling leads to splenic rupture, which can occur spontaneously or be triggered by an injury.

After the initial infection, it can take 4-6 weeks for symptoms to appear. Symptoms usually subside after 14 days, but fatigue may persist for several weeks.

Causes and triggers

Infectious mononucleosis is caused by the Epstein-Barr virus.

The disease is most commonly spread by saliva. Transmission can occur through direct contact (e.g., by kissing the infected person) or indirect contact (e.g., by sharing utensils). The period of contagion is unknown.

The Epstein-Barr virus is very common. About 95 percent of people will contract it during their lifetime, without it necessarily causing mononucleosis. Only a certain percentage of people infected with the virus will develop mononucleosis symptoms. It's extremely rare for the virus to cause mononucleosis in children under age 5. The disease most commonly affects people between the ages of 15 and 24.

Treatment

Mononucleosis treatment consists in supportive care, meaning its purpose is only to reduce symptoms. Acetaminophen (e.g., Tylenol) or ibuprofen (e.g., Advil) can be taken to lower a fever or relieve pain. It's important to rest, stay well hydrated, and maintain a healthy and balanced diet. Contact sports should be avoided for at least 1 month to reduce the risk of splenic rupture.

Antibiotics can't treat mononucleosis, and there is no effective antiviral treatment.

When should I see a health care professional?

Consult a health care professional if you think you have mononucleosis or if you have any of the following symptoms:

• Extreme fatigue
• Persistent fever
• Severe throat pain with whitish, pus-like spots on your tonsils
• Swollen lymph nodes in your neck

You should also consult a health care professional if you have mononucleosis and develop any of the following symptoms:

• Difficulty breathing
• Intense headaches
• Seizures
• Sudden and severe stomach pain