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Infectious Mononucleosis

What is infectious mononucleosis?

Infectious mononucleosis (also called mono) is a viral infection. It is a common infection, but often it does not cause any symptoms, especially when younger children have it. However, for adolescents and young adults it is a frequent cause of illness and missed school.

What is the cause?

The virus that causes infectious mono is called the Epstein-Barr virus (EBV). It is spread mainly through saliva, which is why it has the nickname "kissing disease." Coughing, sneezing, or sharing drinking or eating utensils can also spread the virus.

Mono is most infectious from right before you start having symptoms until several days after your fever is gone.

What are the symptoms?

After the virus enters the body it can take up to a month before symptoms begin. The first symptoms usually are:

  • Tiredness
  • Fever
  • Headache
  • Muscle aches

Many people have extreme tiredness before they have any other symptoms. They may find that they are sleeping 12 to 16 hours a day.

After a few days of tiredness, fever, and aches, other symptoms are:

  • Sore throat
  • Swollen tonsils with a yellowish white coating
  • Swollen glands (lymph nodes) in the neck

You may also have:

  • A loss of appetite
  • Nausea
  • Achy joints
  • A fine, red rash, often on the chest, sometimes including tiny red spots in the mouth

How is it diagnosed?

Your healthcare provider will ask about your symptoms and medical history and examine you. Your provider will look for fever; a red throat with swollen tonsils, sometimes covered with pus; and swollen lymph nodes in the neck. You may also have a red rash, especially on the chest, and an enlarged spleen (in the upper left abdomen).

A blood sample will be taken to test for mono. The first blood test can be negative if the illness is just starting. If your provider thinks you have mono, you may be asked to return in a few days for another blood test. If you have mono, this second test is usually positive.

You may also have a throat swab to check for strep throat.

How is it treated?

There is no specific drug treatment for mono. Because it is a viral illness, antibiotics are not helpful. The most important thing you can do is to get plenty of rest.

Sometimes the mono infection causes the tonsils to become so big that they nearly block the throat. Your healthcare provider might prescribe steroid medicine to try to decrease the size of the tonsils. Using a steroid for a long time can have serious side effects. Take steroid medicine exactly as your healthcare provider prescribes. Don’t take more or less of it than prescribed by your provider and don’t take it longer than prescribed. Don’t stop taking a steroid without your provider's approval. You may have to lower your dosage slowly before stopping it.

How long will the effects last?

Usually the fever, sore throat, and extreme tiredness last about 1 to 2 weeks. However, the tiredness can last for weeks or months. As you recover, you will be able to slowly go back to your normal activities.

An uncommon complication of mono is an abscess (pocket of infection) on 1 or both tonsils. The throat is very painful and swallowing is nearly impossible if you have a tonsil abscess. This infection needs to be treated with antibiotics. Sometimes the abscess needs to be opened by a surgeon.

Another uncommon, but dangerous complication is a ruptured spleen. Like the liver, the spleen can get enlarged during the infection. It can get so swollen that it actually bursts (ruptures). This is most likely to happen if you get hit in the belly, which is why you should not play sports until your healthcare provider says it’s okay. When your spleen ruptures, you may have sudden severe pain in the abdomen or you may feel like you are going to faint. If you have either of these symptoms, you need to call 911 right away.

With mono it can take several weeks, and in some cases several months, for the body's immune system to overcome the virus, but the illness is less contagious after the fever has been gone a few days.

The Epstein-Barr virus stays in the body even after you recover. You could have mono again, but this is unusual.

How can I take care of myself?

  • Follow your healthcare provider's instructions.
  • Get lots of rest.
  • Take acetaminophen or ibuprofen for fever, sore throat, or muscle aches. Don’t use more than the recommended dose. Nonsteroidal anti-inflammatory medicines (NSAIDs), such as ibuprofen, may cause stomach bleeding and other problems. These risks increase with age. Read the label and take as directed. Unless recommended by your healthcare provider, do not take for more than 10 days for any reason. Check with your healthcare provider before you give any medicine that contains aspirin or salicylates to a child or teen. This includes medicines like baby aspirin, some cold medicines, and Pepto-Bismol. Children and teens who take aspirin are at risk for a serious illness called Reye's syndrome.
  • Drink more fluids.
  • Don’t drink alcohol when you have mono. The virus can inflame your liver and alcohol could further hurt your liver.
  • Avoid heavy lifting and any kind of jarring activity or contact sport for about 1 month. If your spleen is enlarged from the mono, it could rupture if it is hit or strained. A rupture of the spleen causes severe bleeding and is a medical emergency. Check with your healthcare provider about how long you should avoid these activities.
  • Ask your provider:
    • How and when you will hear your test results
    • How long it will take to recover from this illness
    • What activities you should avoid and when you can return to your normal activities
    • How to take care of yourself at home
    • What symptoms or problems you should watch for and what to do if you have them
  • Make sure you know when you should come back for a checkup.

How can I help prevent mononucleosis?

The best way to prevent others around you from getting mono is for them to avoid contact with your saliva. They should avoid kissing you and not share food, eating utensils, or drink containers with you until it has been several days since you stopped having a fever. The virus is less contagious at this time.

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Published by RelayHealth.
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