Infectious mononucleosis is an illness caused by a viral infection. It is commonly called mononucleosis, or "mono." Mononucleosis is most often caused by the Epstein-Barr virus. In some cases, it is caused by other viruses.
Mononucleosis has been nicknamed the "kissing disease." This is because Epstein-Barr virus commonly is transmitted during kissing. However, sneezes and coughs also can transmit the virus.
Mononucleosis typically occurs the first time a person is infected with Epstein-Barr virus. But infection with Epstein-Barr virus does not always cause mononucleosis. It often causes only a mild illness or no illness at all.
The first symptoms of mononucleosis typically include:
These symptoms are followed very shortly by:
Rare symptoms include:
In rare cases, an enlarged spleen can rupture. The spleen is a small organ near the stomach. Untreated, a ruptured spleen can cause life-threatening internal bleeding.
Your doctor will ask you about your medical history and current symptoms. He or she will want to know about recent exposure to anyone with mononucleosis or mono-like symptoms.
During a physical exam, your doctor will look for signs of mononucleosis. These include:
Your doctor also will do blood tests to help make the diagnosis. The results of these blood tests may not be abnormal until the person has been ill for a week.
Two types of blood tests help to make the diagnosis:
Symptoms usually are most intense during the first two to four weeks of the illness. But some symptoms, especially fatigue, can last for several months or longer.
This disease is most contagious during its acute stage. This is when the affected person still has a fever.
Someone with mononucleosis does not need to be kept isolated from others. However, many doctors recommend that the patient avoid kissing others while he or she is feeling ill. This helps to prevent the spread of the infection.
Some authorities also advise avoiding sharing food, drinks or eating utensils during the first few weeks of the illness.
There is no medical cure for mononucleosis. It usually goes away on its own.
Most treatment focuses on making the person more comfortable. Recovery usually calls for getting plenty of rest and fluids and treating symptoms.
Cold drinks, frozen desserts and gargling with salt water can help to relieve minor sore throat pain.
Ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) can be taken to fight fever and body aches.
Prednisone can shrink tonsils that are so swollen it is hard to breathe.
It is important to protect the spleen from rupture. Avoid strenuous activities, especially contact sports, for at least four weeks.
Call your doctor if you develop the symptoms of mononucleosis.
If you have been diagnosed with mononucleosis, contact your doctor immediately if:
Most patients with mononucleosis recover completely. Some people with the illness develop strep throat. This is a bacterial infection that needs to be treated with antibiotics.
Center for Food Safety and Applied Nutrition
U.S. Food and Drug Administration (FDA)
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College Park, MD 20740-3835