Mononucleosis (Mono): Symptoms, Treatment & Diagnosis

 Infectious mononucleosis is a disease caused by the Epstein-Barr virus. Mononucleosis mainly affects adolescents and young adults, but it can also affect children. In children, it is usually silent and therefore undetected.

 What is mononucleosis?

Mononucleosis is most often manifested by a sore throat, headache, extreme fatigue, loss of appetite and a feeling of weakness throughout the body. The degree of fatigue, especially in the acute phase, can vary greatly from person to person. Some people who are more severely affected have to stop their activities for a few weeks. In any case, sport is not recommended for everyone during the acute phase because of the risk to the spleen.

It is also known as kissing disease, because most of the time the virus is transmitted through saliva. However, kissing is far from always the cause (eating with the same cutlery, sharing a toothbrush, etc. can also promote the transmission of the virus, as can droplets of saliva ejected into the air during a coughing effort, for example). In the end, people who are ill usually do not know how they got the disease, but that is not the most important thing!

Mononucleosis gets its name from the fact that the virus causes a proliferation of white blood cells called monocytic lymphocytes or monocytes (lymphocytes, which have only one nucleus) in the blood.

See the symptoms of mononucleosis.

Is it possible to have mononucleosis without knowing it?

It is possible. Most of the time, when Epstein-Barr virus infection occurs in young children, the symptoms are so mild that they go unnoticed. Moreover, they can easily be confused with the many other minor sore throats experienced in early childhood. On the other hand, when the first contact with the virus is made in adolescence or early adulthood (15-25-year-olds are the most affected), the infection is accompanied by mononucleosis in 1 out of 2 cases. The symptoms are usually much more severe. It is not known why some people develop it and others do not. One thing is certain, however: if you have had mononucleosis, you will not get it again.

How do you get mononucleosis? Is it highly contagious?

The Epstein-Barr virus is very contagious, but not as contagious as the common cold because it does not cause sneezing. It is transmitted by saliva, therefore by kissing, exchanging utensils, soiled objects, or from mother to child.

An infected person is contagious from the moment he or she is infected. They are therefore contagious during the incubation period: 4 to 6 weeks before the onset of symptoms. Once cured, the person remains contagious for several months. However, the risk of contagion is higher in the first weeks of the disease, when there is a fever and a sore throat. Parents are asked not to send their child or teenager to school during this period. In adults, time off work may be prescribed as long as symptoms are present.

How long does mononucleosis last?

After entering the body, the virus first proliferates in the mouth. It then travels to the lymph nodes and the blood. The incubation period is 4 to 6 weeks from the time the virus enters the body until the onset of symptoms.

Acute symptoms last 2 to 3 weeks. A state of fatigue may persist for several months.

Most infectious mononucleosis will heal in three to five weeks, with fatigue lasting a few weeks longer.

After that, the virus remains "hidden" in the immune system without causing any symptoms and without reappearing (except in cases of immunosuppression).

How do you identify mononucleosis?

The doctor takes a throat swab to distinguish infectious mononucleosis from bacterial angina (sore throat).

Blood tests are ordered to confirm the diagnosis of mononucleosis: they look for the presence of specific antibodies to the Epstein Barr virus (EPV). This rules out the possibility that the symptoms are caused by another disease (cytomegalovirus or CMV infection, toxoplasmosis, etc.). This distinction is particularly important for pregnant women: EPV is not dangerous for the foetus, whereas CMV and the parasite responsible for toxoplasmosis are both dangerous.

The doctor also requests (via a blood test):

• a Blood Formulation Count (BFC) which allows the transient increase in monocytic lymphocytes or monocytes to be found;
• liver enzymes: these are often increased, but only moderately.

For people who have had unprotected sex, it may be appropriate to also be tested for the human immunodeficiency virus (HIV). This is because the early symptoms of HIV infection may resemble those of mononucleosis.

Other diseases associated with the Epstein-Barr virus

This virus is involved in the development of Burkitt's lymphoma (see article), a type of cancer that forms in the white blood cells. Burkitt's lymphoma is rare in the West, but endemic in Africa. In the West, it occurs only in people with very weakened immune systems (for example, those who have received anti-rejection drugs after organ transplants or chemotherapy). In Asians (South East Asia, China), Epstein-Barr virus infection is still implicated in nasopharyngeal cancer.

Specifically, there is no specific treatment to cure mononucleosis, but some medications help relieve symptoms.

 What causes mononucleosis?

Mononucleosis is caused by infection with the Epstein-Barr virus. This is an extremely common virus, which is transmitted through saliva but does not always lead to infection. It is even harmless in the majority of cases, and "colonises" us without us even noticing it. In fact, by the age of 5, 50% of individuals are carriers of the Epstein-Barr virus. By adulthood, the percentage is 90%. In some cases, the first infection with this virus causes mononucleosis, and no one knows why.

Antibodies to the virus can be detected in the blood of these people and this protection is long-lasting. Once infected, the person keeps the virus in his or her body for the rest of his or her life, without having any symptoms. It does not recur. However, if a person later becomes immunosuppressed for any reason, a reactivation of the virus becomes possible and it can take a severe, complicated form.

 What are the possible complications of mononucleosis?

Although it causes the proliferation of certain blood cells, mononucleosis is a benign disease in the vast majority of cases. Complications are rare, but can still be very serious.

The most serious complication is the rupture of the spleen (a small organ in the left side of the abdomen that plays a role in cleaning the blood). The infection can cause the spleen to swell (splenomegaly). The spleen may rupture spontaneously or after even a mild shock. This happens rarely (0.5% to 1% of cases)2 , but the risk is real. For this reason, people with mononucleosis should not participate in strenuous or contact sports. When the spleen is swollen, severe pain in the upper left abdomen is felt. This situation requires emergency treatment. Rupture of the spleen causes bleeding into the abdominal cavity and pain throughout the abdomen. It can be fatal and surgery is necessary.

In some cases, the virus causes the tonsils to enlarge significantly, which can obstruct the airway and cause severe breathing difficulties (respiratory distress).

Complications can also occur in the liver, nervous system and red blood cells (hepatitis, jaundice, encephalitis, meningitis, haemolytic anaemia, white blood cell proliferation, etc.).

Immunocompromised people are at greater risk of these complications.

It is rare to hospitalise a person with infectious mononucleosis unless there is a complication.

 People at risk of mononucleosis

Teenagers and young adults, although the disease can occur at any age.

 Risk factors for mononucleosis

Symptoms of mononucleosis are thought to be greater in societies where hygiene measures are predominant. This is because the infection is transmitted later in life (during adolescence rather than childhood). However, when contracted at a young age, the infection causes far fewer symptoms and often goes unnoticed.

 Can mononucleosis be prevented?

There is no way to prevent infectious mononucleosis. There is also no vaccine against the Epstein-Barr virus.

People who are in very poor health and have never had mononucleosis should take a number of steps when they are around people who have mononucleosis or who have had it in the past few months.

To avoid contagion :

• Avoid kissing the person with mono on the mouth;
• Do not share cooking utensils, glasses and dishes with an infected person (and clean them well);
• Do not share food;
• Wash your hands well;
• protect yourself from sneezing and coughing.

How do you recognise mononucleosis?

The symptoms of mononucleosis are

• extreme fatigue ;
• swelling and tenderness of the lymph nodes in the neck: there may be many swollen lymph nodes in the neck;
• fever of up to 40.5ºC (105ºF), often accompanied by chills. Fever and chills may last for one to two weeks;
• a severe sore throat (in extreme cases, not being able to swallow). The throat is red with white deposits or even membranes;
• headaches;
• loss of appetite;
• sometimes generalized muscle pain and joint pain;
• a skin rash may appear, usually after taking antibiotics;
• An enlarged spleen is sometimes noticeable to the doctor (by feeling the abdomen).
• Fever and sore throat last for 2 to 3 weeks, but fatigue may persist for several months.

Important. If you have severe pain in the upper left side of the abdomen, see a doctor immediately. This could mean that the spleen is swollen and liable to rupture.

Treatments for mononucleosis

How can mononucleosis be cured?

There is no specific treatment to cure mononucleosis. It is a mild disease that usually goes away on its own after 4-8 weeks, although fatigue may persist for several months. The aim of treatment is therefore to provide supportive care until recovery.

Some tips for a good recovery

Rest

Have a good rest period (some people will need to leave school or work for a few days or weeks) and gradually resume previous activities. It is important to listen to your body (and in particular to your fatigue) so that you do not ask too much of it, as this may delay recovery.

Drink

Drink plenty of water, broths and juices to prevent dehydration. Be careful, alcohol is not allowed, especially as the liver may be affected.

Gargle

To relieve sore throats, gargle with a salt water solution (½ teaspoon of salt in a glass of water) several times a day.

Choose cold foods

Drink and eat cold or even iced food. When they are not well tolerated, avoid spicy or acidic foods that irritate the throat even more.

Pay attention to the air in the room

The air in the room should not be too dry or too hot. Ideally, the temperature should be below 19°C, with a humidity level of 55%. And to reduce the concentration of microbes in the room where the patient is resting, it is imperative to ventilate (and therefore open the windows wide) for at least 20 minutes, every day and in all weathers.

Balanced diet

Adopt a balanced diet to help the body regain control of the virus (see How to eat well?).

Mononucleosis precautions

Avoid strenuous and contact sports for at least 2 months to prevent rupture of the spleen. The spleen remains fragile even if it is not swollen;

Avoid lifting heavy objects for at least 2 months to avoid rupture of the spleen;

precautions to be taken for the people around you;

the risk of transmitting the virus to those close to you is real. To limit this risk, wash your hands often with soap, use a single-use handkerchief when blowing your nose, sneezing or coughing (and wash your hands well afterwards), do not kiss anyone as long as there is a risk of contagion, do not share food, cutlery or toiletries, and disinfect any object used by the family (such as a telephone, a computer keyboard, etc.)

Medication to relieve symptoms

If necessary, medication can help treat complications or relieve symptoms, if they are severe.

Painkillers

To relieve fever, headaches, sore throat and aches, the doctor may advise taking paracetamol or, if this is not possible, anti-inflammatory drugs that also have an analgesic and antipyretic (fever-reducing) effect, such as ibuprofen. Caution: Aspirin is strongly discouraged for viral infections in children under 16 years of age, as it can cause Reye's syndrome, a rare but serious condition that can lead to neurological and/or liver damage and even death.

Antibiotics

Some people with mononucleosis develop a simultaneous bacterial infection of the throat, sinuses or tonsils. However, certain types of antibiotics, such as ampicillin and amoxicillin, should be avoided as they can cause a skin reaction all over the body in people with mononucleosis. A skin reaction to an antibiotic that occurs during mononucleosis does not necessarily mean that the person is allergic to that drug.

Corticosteroids

Corticosteroids are not prescribed as a matter of course. They are sometimes prescribed for abnormally enlarged tonsils (which may obstruct the airway), or to treat other serious complications, but an analysis of several studies of the use of corticosteroids for symptoms of infectious mononucleosis versus placebo found insufficient evidence of their value in this indication. In addition, there is a lack of research on side effects and long-term complications

 Dr Nathalie Szapiro's opinion on mononucleosis

"Given the high contagiousness of infectious mononucleosis and its potential dangers in an immunocompromised person, it is preferable to consult a doctor to find out whether or not you really have the disease, in the face of evocative symptoms such as a high fever, a sore throat, large lymph nodes in the neck, etc. This also makes it possible to distinguish between bacterial angina, which may give some of these symptoms and which requires antibiotic treatment.

This also makes it possible to distinguish between bacterial angina, which can give rise to some of these symptoms and which requires antibiotic treatment. Thanks to the RDT test for rapid diagnosis of strep throat (the doctor just takes a swab from the tonsils and places it in a tube containing a reagent), it takes no more than a few minutes to tell the difference between these two infections.

If infectious mononucleosis is confirmed, the risk of contagion is significant. It is important to take the usual precautions with healthy relatives, but it is even more important if you have sick or frail relatives. For example, it is really not a good idea to visit an elderly person or someone being treated for cancer. There are safe ways to talk to them face to face (Skype, Facetime, etc.)!

Finally, you should seek urgent medical attention if the fever remains above 40°C despite paracetamol or ibuprofen, if it is difficult to breathe, if there is abdominal pain (leading to fears that the spleen may be affected), in case of jaundice, or finally, if the state of health worsens, in case of neurological damage (Guillain-Barré syndrome responsible for temporary paralysis), if the headaches are intense and accompanied by difficulty in seeing the light (suspicion of meningitis), etc. "

 Complementary approaches to treating mononucleosis

Rest is the main treatment. No specific complementary approaches have been studied.

For the basics of a healthy immune system (sleep, exercise, stress control, etc.), see our Strengthening Your Immune System fact sheet.

Note: Muscle massages are not recommended if you have a fever1. It is best to wait until the signs of infection (swollen glands, fever, malaise) disappear before receiving one. If in doubt, ask a trained massage therapist.