Glandular Fever Infectious Mononucleosis

Authored by , Reviewed by Dr Hayley Willacy | Last edited | Meets Patient’s editorial guidelines

Glandular fever (infectious mononucleosis) is caused by the Epstein-Barr virus. Although it can make you feel quite ill, full recovery is usual. It is a self-limiting illness which means it usually goes away by itself.

Glandular fever is a viral infection caused by the Epstein-Barr virus. This virus can be passed from person to person by close contact (especially kissing). It can possibly also be caught by sharing cups, toothbrushes, etc. It can take up to six weeks for the symptoms to develop after a person has first been infected with this virus. This is called the incubation period.

Glandular fever can affect people of any age but is most common in young adults and teenagers. The immune system makes antibodies during the infection. This then usually provides lifelong immunity. This means that it is rare to have more than one episode of glandular fever.

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One or more of the following symptoms commonly occur for about a week or so. Symptoms then usually gradually settle over another week.

  • Sore throat. Although this may be mild, your throat is usually very sore, red and swollen. Glandular fever is typically suspected when a tonsillitis is severe and lasts longer than usual. Swallowing is often painful and saliva may pool in your mouth.
  • Swollen glands. As your body's immune system fights off the virus it causes the lymph glands to swell. Any lymph gland in the body can be affected. However, the glands in the neck are usually the most prominent. They can become quite large and tender.
  • Flu-like symptoms. Like other viral infections, glandular fever often causes a high temperature (fever), muscle aches and headaches. It can make you feel quite unwell.
  • Malaise. A feeling of intense tiredness often develops with glandular fever. This is often the last symptom to go.
  • Swelling around eyes. About 1 in 5 people with glandular fever become quite puffy and swollen around the eyes. This goes in a short time.
  • Spleen. This is an organ under the ribs on the left side of the tummy (abdomen). It is part of the immune system. Like the lymph glands, it swells and can sometimes be felt below the ribs if you have glandular fever. Very occasionally, it causes mild pain in the upper left abdomen.
  • No symptoms. Many people become infected with this virus but do not develop symptoms. This is called a subclinical infection. This is more common in children and in those aged over 40 years.

The symptoms caused by glandular fever are similar to symptoms due to various other viruses. Therefore, it can be difficult to diagnose glandular fever just by a doctor examining you. So, a blood test is commonly done that can detect a particular antibody and confirm if you have glandular fever. If your blood test is negative but your doctor suspects you have glandular fever then you may have your blood test repeated a few weeks later.

Most people with glandular fever do not have complications or rare symptoms. If complications do occur, they may include:

  • Damaged spleen. This is serious but rare. The spleen is an organ under the ribs on the left side of the tummy (abdomen). A swollen spleen is more delicate than normal. A damaged spleen may occur if the left side of the chest or abdomen is injured - for example, after a fall. The spleen normally settles down to its normal size after about three weeks. However, one study found that in 3 out of 19 people it took eight weeks. Therefore, if you want to be absolutely sure, you should not play rough or contact sports such as rugby for eight weeks after having glandular fever.
  • Rash. A widespread, non-itchy red rash occurs in some people with glandular fever. This usually fades quickly.
  • Jaundice. The Epstein-Barr virus causes mild inflammation of the liver in 1 in 10 young adults and in 30 out of 100 older patients. It usually clears up quickly without treatment and may cause no symptoms at all. Rarely, it can cause yellowing of the skin (mild jaundice).
  • Malaise and depression. It is common to feel tired and low for the duration of the illness and for a week or so afterwards. Some people develop 'postviral fatigue' for variable periods. This usually clears in time.

Usually, no specific treatment is needed. However, it is important to have plenty to drink. It is often tempting not to drink very much if it is painful to swallow. This can lead to mild lack of fluid in the body (dehydration), particularly if you also have a high temperature (fever). Mild dehydration can make headaches and tiredness much worse. It can be worthwhile taking paracetamol or ibuprofen to ease pain, headache and fever.

Some studies have looked at the use of steroid medicines for people with glandular fever. The theory was that steroids help to reduce inflammation in various conditions and so may do so for glandular fever. However, there is currently not enough evidence to recommend the use of steroids to treat people with glandular fever.

To prevent spread, you should avoid kissing and close body contact with other people whilst you are ill. It is also best not to share cups, towels, etc, whilst you are ill. There is no need to miss any school if you have glandular fever, unless you feel unwell. You should see your doctor if any unusual, severe or unexplained symptoms develop.

If you drink alcohol when you are unwell with glandular fever, you can feel much worse than usual because of the effect of glandular fever on the liver. You should therefore not drink any alcohol if you have glandular fever until you are better.

Antibiotic medicines are not usually used, as glandular fever is caused by a virus. Antibiotics do not kill viruses. Occasionally, an antibiotic is prescribed if you develop a secondary throat infection that is caused by a germ (bacterium) which does then respond to antibiotics.

A full recovery is usual within a couple of weeks. Some people have a lingering tiredness that lasts a few weeks, sometimes longer. It is rare to have glandular fever again.


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Further reading and references