Mononucleosis primarily affects adolescents and young adults, although it can also affect children. In the latter, it is generally asymptomatic and therefore often goes unnoticed.
1. Definition of mononucleosis
Infectious mononucleosis, also known as “kissing disease”, is a viral infection caused by the Epstein-Barr virus (EBV), a herpesvirus. This generally benign disease affects approximately 90% of the population, depending on the French Language Resuscitation Society. The first contact with the virus, called primary infection, often goes unnoticed in children, but can lead to infectious mononucleosis, more common in adolescence. This condition is characterized by the presence of a blood mononucleosis syndrome, observed in blood tests such as blood count or hemogram. Although usually attributed to the Epstein-Barr virus, this syndrome can be seen in other contexts, such as other viral infections or when taking certain medications, including certain antibiotics or epilepsy treatments.
2. Symptoms of mononucleosis
As stated in the MSD Manual, primary infection with Epstein-Barr virus is generally asymptomatic in most young children. However, symptoms of infectious mononucleosis occur more commonly in older children and adults. The incubation period of the disease is approximately 30 to 50 days, with persistent fatigue that can extend over several months, peaking in the first 2 to 3 weeks. Most patients present with the classic triad of fever, pharyngitis and lymphadenopathy. The fever peak usually occurs in the afternoon or evening, reaching around 39.5°C, but can reach 40.5°C. Pharyngitis can be severe, painful, and exudative, sometimes resembling streptococcal pharyngitis. Lymphadenopathy, often symmetrical, can affect various groups of lymph nodes, particularly those of the anterior and posterior cervical chains. Lymphadenopathy can sometimes be the only manifestation of the disease. Other symptoms and signs include splenomegaly, mild hepatomegaly with hepatic pain on percussion, periorbital edema, and palatal petechiae. Maculopapular rashes are less common, and jaundice is rare.
3. Causes of mononucleosis
The Epstein-Barr virus is spread primarily through direct contact between individuals, such as kissing, as well as through saliva, particularly through splashes during coughing. Children infected with the virus usually show no symptoms, but develop antibodies that make them immune to infectious mononucleosis, without developing the disease. With the increasing adoption of hygiene measures, the number of immunized children is decreasing in developed countries. Contamination then occurs later in life, generally during adolescence or early adulthood, during intimate contact with other people. This is why infectious mononucleosis is commonly called the “kissing disease.”
The period of contagion peaks during the acute phase of the disease, characterized by fever. Even after the fever disappears, the virus persists in saliva in small quantities for up to six months after contamination, maintaining the possibility of transmission. After recovery from the disease, the virus remains in the lymph nodes for life without causing recurrences of mononucleosis. Following this infection, the person acquires prolonged immunity.
4. Mononucleosis: when to consult?
No specific treatment is prescribed for this viral illness, which generally tends to resolve spontaneously three to four weeks after symptoms appear. It is important to emphasize that antibiotics are ineffective, given that the disease is of viral and not bacterial origin. Rest turns out to be the best medicine. Painkillers and antipyretics, such as paracetamol, can be used to reduce fever and relieve pain. It is also recommended to humidify the ambient air in the bedroom, as air that is too dry and hot can aggravate sore throats. It is imperative to consult a doctor urgently in the event of breathing difficulties, major problems swallowing, intense pain on the left side of the abdomen, under the ribs (where the spleen is located), stiffness and pain in the of the neck, or if the general state of health does not improve after two weeks.
Although mononucleosis can cause an overgrowth of certain blood cells, it is generally mild in most cases. Complications are rare, but can be serious. Rupture of the spleen, which occurs rarely, is the most serious complication and can be fatal. Demanding and contact sports are not recommended in cases of mononucleosis, due to the increased risk of rupture of the spleen. A significant enlargement of the tonsils can lead to difficulty breathing. The virus can also cause complications in the liver, nervous system and red blood cells, causing hepatitis, jaundice, encephalitis, meningitis, hemolytic anemia, white blood cell overgrowth, etc. People who are immunocompromised are more likely to develop these complications. Hospitalization is generally only necessary in the event of deterioration in the patient’s state of health.
5. Examinations and diagnostics of mononucleosis
Your doctor performs a thorough examination, including inspecting your tonsils, to detect the presence of angina characteristic of infectious mononucleosis. Swollen, red tonsils covered with whitish membranes, as well as large lymph nodes in the neck, are typical indicators of this disease. Additionally, the doctor will palpate your abdomen to assess the size and tenderness of the spleen. In order to eliminate angina of bacterial origin, he carries out a rapid diagnostic orientation test (Trod), a simple and painless process which only takes a few minutes. Trod angina involves taking a sample from the tonsils using a swab, which is then placed in a tube containing a reagent. A strip immersed in this liquid tells the doctor, based on its color, if the angina is caused by a bacteria, in this case group A streptococcus.
To confirm mononucleosis virus infection, your doctor may also order a blood test. This analysis aims to highlight mononucleosis syndrome, characterized by a temporary significant increase in certain white blood cells called monocytic lymphocytes or monocytes, with distinct microscopic abnormalities. In addition, the search for antibodies directed against the Epstein-Barr virus makes it possible to confirm recent contact with the virus, while the evaluation of liver enzymes makes it possible to assess the consequences of the infection on the liver, generally marked by a moderate increase.
6. Treatments for mononucleosis
There is no specific treatment for infectious mononucleosis; being of viral origin, antibiotics prove ineffective. To reduce fever and relieve pain associated with infectious mononucleosis, analgesics and antipyretics, preferably paracetamol, may be prescribed. In the event of complications, hospitalization may be considered by the attending physician, although this remains exceptional. The duration of a temporary work stoppage is adapted to the severity of the symptoms, such as disabling fatigue, persistent fever, or established joint and muscle pain. For children and adolescents, school absence continues until symptoms disappear. They can return to class as soon as the fever is gone and they can swallow normally. It is important to emphasize that antibiotics are not effective in treating infectious mononucleosis.
7. How to prevent mononucleosis?
It is currently not possible to prevent infectious mononucleosis, and there is no vaccine against the Epstein-Barr virus. For people with particular fragility and who have never contracted mononucleosis, it is recommended to adopt various measures when in contact with individuals suffering from the disease or who have recently had it. To reduce the risk of contagion, it is recommended to:
- Avoid kissing on the mouth with a person with mononucleosis.
- Refrain from exchanging kitchen utensils, glasses and dishes with an infected person, while ensuring they are cleaned thoroughly.
- Do not share food.
- Protect yourself from sneezing and coughing.
Good hand hygiene is essential to protect against infectious diseases. To do this, wash your hands thoroughly, using liquid soap if possible, and rubbing them vigorously for 30 seconds. Then rinse them under running water and dry them with a clean towel or in the open air. Integrate hand washing as a reflex, particularly before preparing or consuming a meal, after blowing your nose, sneezing or coughing while covering your mouth, after using the toilet, taking public transport, or having contact with a person. animal, and systematically after returning home.
Sources
- Serious acute infections with Epstein-Barr virus, French-speaking intensive care society, Grenoble University Hospital, 2005
- Infectious Mononucleosis, The MSD Manual – Healthcare Professional Version, December 2023
- Infectious mononucleosis, Health Insurance, December 2023
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