Mononucleosis in children: infection, symptoms and treatment


In this article:

  • what is mononucleosis and why it is also called glandular disease or kissing disease;
  • how common is mononucleosis and which age groups are most affected;
  • what are the symptoms of mononucleosis and how is it recognized; 
  • how it is transmitted;
  • how the diagnosis is made;
  • how to cure it, how to fight fatigue and what to do if the child is not hungry;
  • how long it is contagious and after how long can you go back to school and to play sports;
  • how it is and how long the course lasts;
  • what are the possible complications;
  • how to prevent mononucleosis;
  • mononucleosis and newborns;
  • mononucleosis and pregnancy.

He answers questions, explaining everything about the mononucleosis in children and adolescents, the pediatrician Alberto Villani, head of the General Pediatrics and Infectious Diseases Unit of the Bambino Gesù Pediatric Hospital in the city. 

What is mononucleosis and is it also called glandular or kissing disease?

Mononucleosis is one highly contagious infectious disease of viral origin. It is usually caused by the Epstein-Barr virus (EBV) which belongs to the family of herpes virus, the same viruses that cause chicken pox, cold sores or genital herpes and Sant 'fire. In some cases it is caused by other viruses such as the Cytomegalovirus.


Mononucleosis: photos and pictures of the "kissing disease"

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Also known as "kissing disease", mononucleosis is a viral infection caused by a virus that belongs to the Herpesviridae family, ...

Why is it also called glandular or kissing disease?

It is also called glandular disease because it affects various glands: one of the most typical manifestations is in fact the enlargement of the tonsils, accompanied in almost all cases by swollen lymph nodes in the neck, sometimes of the spleen and liver.

Finally, it is known as kissing disease since it is transmitted through the exchange of saliva, as well as through the respiratory droplets that are dispersed after coughing or sneezing, or by using contaminated objects such as toys, cutlery, glasses and plates. In fact, the kiss is not at all the first responsible for the disease, but it is more frequent that the infection occurs for example by drinking from the same glass.

How common is mononucleosis and which age groups are most affected?

There is no reliable data on this, why mononucleosis often has very nuanced symptoms which make it mistaken for other forms of infections: this is why it is often not diagnosed. Only 5-10% of those who get mononucleosis have manifest symptoms, another 10% have vague ailments, such as sore throats and small spots on the skin, while the majority of individuals who come into contact with the Epstein virus- Barr has no symptoms.

However, it has been found that, if in adulthood the search for antibodies in the blood is done, in most cases the result is positive, a sign that the individual has had contact with the virus in the past.

Which age groups are most affected?

Mononucleosis occurs mainly from preschool onwards and in particular in adolescence (between 15 and 24 years there is the maximum peak of incidence), while it is rare under 2 years and after 40 years.

Does mononucleosis give immunity?

On the one hand, it is true that after contracting the disease, antibodies develop (the IGGs, which are the trace of the past infection), which protect against new infections coming from the outside. On the other hand, however, it is also true that the virus persists for a long time in the organism and can give rise, albeit rarely, to reactivation phenomena, especially in moments when the immune defenses are lowered.

A bit like what happens to the chickenpox virus, which remains latent and can flare up over the course of life giving rise to the so-called 'fire of Saint', even if reactivations are much less frequent for mononucleosis than for chickenpox.

What are the symptoms of mononucleosis and how is it recognized?

As already mentioned, mononucleosis does not always give symptoms. Furthermore, the younger the child, the less evident are the manifestations, while in the older child and adolescent it is easier for him to give signals, which are different depending on the stage of the disease.

In the initial phase (7-15 days), flu-like symptoms may appear, such as:

  • generic malaise, with tiredness and listlessness;
  • sore throat;
  • bellyache;
  • some nausea and headache;
  • not very high fever;
  • sometimes sweating and chills. 

Later more specific symptoms may appear:

  • throat inflammation, red spots on the palate, enlargement and presence of secretions on the tonsils, which resemble the classic plaques of tonsillitis and which make swallowing difficult and painful;
  • high fever, about 38-39 °, at least in the most critical phase of the disease;
  • enlarged lymph nodes of the neck and, less frequently, of other sites, such as armpits and groin;
  • in about 10% of cases, an exanthema similar to that of measles may also appear, sometimes caused by the same toxins as EBV, but more often linked to the intake of a certain type of antibiotic, amoxicillin: that is, if the child takes amoxicillin (perhaps because mononucleosis is not recognized and a bacterial infection is thought to be), may see patches appear all over the body. 
  • in adolescents it is very easy for the spleen (splenomegaly) and the liver (hepatomegaly) to enlarge;
  • less frequently, there may be swelling of the eyelids.
Read also: Fever in children: how to behave

How is mononucleosis transmitted?

As anticipated, mononucleosis is transmitted through the exchange of saliva (for this it is also called kissing disease) or through the respiratory droplets that disperse after coughing or sneezing. Finally, it can be transmitted through the sharing of contaminated items from an infected person such as toys, cutlery, glasses, plates or even lipsticks.


Il incubation period it is about 10-15 days in children, 1 month-1 and a half months in adults.

How is mononucleosis diagnosed?

The diagnosis is mainly clinic if symptoms are manifest. If you are suspicious, do a blood test to determine signs of infection, transaminase, bilirubin, but above all it makes the search for specific antibodies to EBV, with the dosage of the IGMs, which signal the infection in progress, and the IGGs, which are the 'memory' antibodies because they remain over time and are the trace that the infection has occurred.

Other tests, such as the Paul-Bunnel-Davidsohn reaction, the so-called monotest and the monospot, are now considered out of date.

How is mononucleosis treated?

There is no specific therapy for mononucleosis.

The best cure is keep the baby at rest and possibly give paracetamol if there is a high fever and malaise. Antibiotics should not be given because it is a viral disease. This unless bacterial superinfections arise, among other things infrequent, which must however be ascertained by the pediatrician.


In selected cases, there may be an indication for the use of oral cortisone, for example if the tonsils are so bulky as to cause difficulty in breathing or if the spleen is really very enlarged. But once again it must be the doctor who determines the need.

Also read: When to give antibiotics to children

How can you fight the fatigue of the child with mononucleosis?

It is enough to get the baby to sleep a little more, to avoid making him fatigued, to feed him regularly. Sometimes a multivitamin supplement can be useful, always on the advice of the doctor, because the infectious processes and in general the episodes of illness easily "consume" vitamins and micronutrients such as zinc and iron.

What to do if the child with mononucleosis has no appetite?

It is a normal reaction and there is no need to worry, considering that it is one temporary lack of appetite and that Western children have the opposite problem of being overfed, so a few days of 'diet' does no harm.

How long is mononucleosis contagious and after how long can you go back to school and play sports?

Mononucleosis is contagious since in which the first symptoms appear while it is not contagious in the incubation phase.

The duration of the contagiousness is variable: if in the great majority of cases the virus is eliminated in a few weeks, in some subjects it can remain in the saliva even for many months. A person can be said to be contagious as long as the IGMs are positive, a sign that the virus is still circulating in the body.


How long does it take for a child with mononucleosis to go back to school?

Usually 2-3 days after the fever subsides. And if he has had more important ailments, with more marked fatigue, it may be appropriate to keep him at home a few more days. It is indeed true that it is a debilitating disease, especially from the immune point of view, for which the child is more vulnerable to other infections for a few weeks.

How long does it take for a child with mononucleosis to resume sports?

After a week without fever, unless there has been a noticeable increase in the volume of the spleen, which makes it advisable to avoid strain or risk of trauma. In this case, the pediatrician will suggest the timing of the recovery.

Read also: Here's why children who are still sick shouldn't go back to school

How is the course of mononucleosis and how long does it last?

In the vast majority of cases, mononucleosis is a troublesome but not serious disease, which has a benign course.

After the initial phase with mild symptoms, which lasts 7-15 days, mononucleosis has an acute phase of about 15 days, with the appearance of the most important symptoms, after which most of the disorders disappear spontaneously. Alone fatigue it can last for weeks or even months.

What are the possible complications of mononucleosis?

The first thing to point out is that complications of mononucleosis are the exception, not the rule. The most feared is the rupture of the spleen, but it is an event that can only happen when the spleen is particularly enlarged and there is a trauma in the area. Other complications are also rare, which can be the most varied and can affect various systems of the body, furthermore, there may be a temporary reduction in the number of some blood cells (platelets, granulocytes) and hemoglobin.

In cases where mononucleosis has more prominent and persistent symptoms, the doctor will carefully monitor the course of the disease.

What are the mononucleosis prevention rules?

Preventing mononucleosis is difficult, also because the symptoms are often faded and you don't know you have it and therefore are contagious.


As general rules they are sufficient normal hygiene measures, how to use bottles, dishes and personal towels, wash dishes with detergent, by hand or in the dishwasher. There is no need for 'sterilizing' washing at particularly high temperatures: what must be avoided is to rinse the used dishes only with water.

My older son has mononucleosis and I have another baby just a few months old: can it be dangerous for the baby?

It is not the case to put the big brother 'in isolation', but as a precaution we must avoid making him kiss the newborn, being in close contact with him, giving him toys or various objects that he has put in his mouth.

For the rest, it is recognized that almost always the mother has already contracted mononucleosis in the past, for which in pregnancy, via transplacental route, she passed her antibodies, which protect him in the first months of life.

Read also: Babies, Christmas and other winter holidays and birthdays: how to behave

I am pregnant and have another child with mononucleosis: can it be dangerous for the fetus?

No. Mononucleosis is not one of the diseases that, contracted during pregnancy, cause fetal malformations or increase the risk of complications.

The only drawback is that it can reduce the immune defenses of the expectant mother and expose her more to infections, for this reason it is still worth following the usual hygiene rules of prevention: avoid direct contact with saliva, do not exchange cutlery and do not eat food. leftover food on his plate.

Read also: Toxoplasmosis in pregnancy: 7 things to know

Other sources for this article: information material of the Bambino Gesù Pediatric Hospital in the city; information material from the Healthy Children website, edited by the American pediatricians association. 

Updated on 09.01.2022

  • mononucleosis
  • fatigue
  • infectious diseases
  • 3-5 children years
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