Mononucleosis – Causes, Signs and symptoms

Mononucleosis

Also called: Infectious Mononucleosis, Kissing Disease, Mono, Glandular Fever, Chronic Mononucleosis, Pfeiffer’s Disease

Summary

Mononucleosis (mono) is a disease usually caused by infection with the Epstein-Barr virus (EBV). It is transmitted from person to person via saliva and mucus and most often affects adolescents and young adults. In the United States, as many as 95 percent of adults between 35 and 40 years of age have already been infected with EBV, according to the U.S. Centers for Disease Control and Prevention (CDC).

Signs and symptoms of mono may vary among patients. Fatigue is one of the main symptoms of mono. Other symptoms include fever, sore throat and swollen lymph nodes. Young children who contract the virus often do not display any symptoms, or they experience minor symptoms similar to those associated with minor respiratory infections.

However, mono may cause various medical complications, including inflammation of the spleen and liver. Severe complications are most likely to appear in people who have impaired immune systems or who are taking medications to suppress their immune systems after an organ transplant.

Generally, the presence of fever, sore throat and swollen lymph nodes for between one and four weeks is enough for a physician to suspect a diagnosis of mononucleosis. Blood tests may be performed to confirm a current infection. Other blood tests may determine whether a patient was ever previously exposed to the virus that causes mono.

Generally, no medical treatment for mono is necessary. In most cases, patients may be advised to get adequate rest and consume plenty of fluids. Antibiotics are not used to treat mono because these drugs have no effect on viral infections. It may take two to three months before a person is fully recovered.

After a person is infected with EBV, the virus remains in the body for a lifetime. However, after initial exposure to the virus, people typically build up antibodies that help prevent a future infection. The virus may occasionally reactivate throughout a person’s life and be intermittently released into their saliva. This causes no symptoms of infection, but may expose others to the virus.

About mononucleosis

Mononucleosis (mono) is a disease transmitted from one person to another by contact with infected drops of saliva and mucus. Often referred to as “the kissing disease,” it can be spread through kissing, coughing, sneezing or sharing drinking glasses, eating utensils and other items that have had oral contact with an infected person.

In rare cases, mono has also been spread through blood transfusions and bone marrow transplants. Although mono is infectious, it is not as contagious as the common cold and some other infectious diseases.

The Epstein-Barr virus (EBV) causes most cases of mono. cytomegalovirus (CMV) may cause symptoms similar to mononucleosis, although the tests for the condition will be negative. Both viruses are members of the herpes virus family and are sometimes linked to certain other medical conditions. Once a person is infected, the virus remains in the body for a lifetime. However, once exposed to the virus, a person usually develops immunity to EBV. Antibodies produced in response to the virus remember the virus and do not allow subsequent exposure to develop into an infection.

In addition, the virus may occasionally reactivate throughout a person’s life and be intermittently released into their saliva. This causes no symptoms of infection, but may expose others to the virus.  

EBV is most likely to infect people during early childhood. A second infection peak occurs during adolescence. An EBV infection typically does not cause any symptoms in young children. However, adolescents and young adults who become infected with Epstein-Barr often develop symptoms of mono. Approximately 35 to 50 percent of people in this age group develop symptoms of infection, according to the U.S. Centers for Disease Control and Prevention (CDC).

Most adults have either experienced asymptomatic exposure to EBV as young children, or symptomatic exposure as teens or young adults. Thus, most adults have already developed the antibodies that protect them against EBV infection and mono. In the United States, as many as 95 percent of adults between 35 and 40 years of age have already been infected with Epstein-Barr virus, according to the CDC.

Symptomatic mono is more common in countries with generally high levels of hygiene (e.g., the United States), than in the developing world. In regions with poor hygiene, more children are likely to be exposed to the EBV early in life, in which case symptoms usually do not develop or are very mild. On the other hand, in industrialized nations with high levels of hygiene, children may not be exposed to the virus until they are adolescents or young adults, at which point symptoms of mono typically develop.

Complications and related conditions

Mononucleosis (mono) may cause various complications that can have serious health consequences. Inflammation of the liver is common and may result in jaundice, which causes yellowing of the skin and the whites of the eyes. Many people with mono also experience low platelet counts, which may interfere with the ability of blood to clot

In rare cases, enlargement of the spleen may lead to rupture. The spleen is located in the upper part of the abdomen on the left side. It helps to filter the blood of impurities and pathogens. When the spleen ruptures, it may feel like a sharp, sudden pain in the left side of the upper abdomen. Other symptoms associated with rupture of the spleen include lightheadedness, feeling like the heart is beating fast and hard, a tendency to bleed more easily than usual and breathing problems. This is a potentially serious condition that requires immediate emergency medical attention. Because of the risk of trauma to the enlarged spleen (splenomegaly), it is recommended that contact sports be avoided until the mononucleosis has resolved and enlargement of the spleen is no longer present or suspected.

Other uncommon complications associated with mono are:

  • Anemia (reduction of red blood cells)
  • Inflammation of the heart
  • Pink rash (may develop in people with mono who are also taking various antibiotics)
  • Nervous system problems (e.g., Bell’s palsy, encephalitis, Guillain-Barre syndrome, meningitis, seizures)
  • Swollen tonsils that cause obstructed breathing and swallowing difficulties that can lead to dehydration

Severe complications are most likely to appear in people who have impaired immune systems or who are taking medications to suppress their immune systems after an organ transplant. People with the human immunodeficiency virus (HIV) may have white tongue lesions (oral hairy leukoplakia) that contain the Epstein-Barr virus.

In very rare cases, chronic mono appears to be related to the development of Burkitt’s lymphoma and nasopharyngeal carcinoma, two rare cancers that typically do not occur in the United States. Burkitt’s lymphoma occurs in certain regions of Africa and the Caribbean, and it has the same geographical distribution as malaria in that locale.

The Epstein-Barr virus has been linked to several other conditions, including several cancers and multiple sclerosis. These links are not well understood. Many studies have been and are being conducted to investigate these relationships.

Risk factors and causes of mononucleosis

In most cases, mononucleosis (mono) is a result of infection with the Epstein-Barr virus (EBV). Another type of virus called cytomegalovirus (CMV) sometimes causes mono, but this is rare. After initial exposure to the virus, a person develops immunity (protection against future infection) to it. However, the virus remains in a dormant state in the body for a lifetime and it may occasionally reactivate. This does not cause symptoms of infection, although it may expose others to the virus.

The disease itself is transmitted through infected saliva. People may become infected through the transfer of saliva during open-mouth kissing. Mono can also be spread as the result of sharing food, beverages, eating utensils, straws, toothbrushes, cosmetics or pillows. People may also inhale droplets spread by infected patients who sneeze or cough. However, mono is not spread as easily as other common respiratory infections (e.g., colds, the flu, strep throat).

People can become infected with the virus that causes mono at any age. However, adolescents and young adults have an increased risk of developing symptoms of mono. This is because children exposed to the virus often develop no symptoms or very minor symptoms that go unnoticed. It is only when first exposure to the virus occurs after childhood that symptoms of mono develop. Many children may not be exposed to the virus until their teens or as a young adult, and thus it is adolescents and young adults who are most likely to experience symptomatic mono. By the age of 40, most adults in the United States have already been exposed to the virus and are immune from infection.

People who receive blood transfusions and bone marrow transplants may have an increased risk of contracting mono, although these routes of transmission are rare. People with impaired immune systems or who are taking certain medications that suppress immune system function have an increased risk of experiencing severe complications if they contract a mono infection.

Signs and symptoms of mononucleosis

Signs and symptoms of mononucleosis (mono) can vary. Young children who are infected by the Epstein-Barr virus (EBV) often do not display any symptoms, or they experience minor symptoms similar to those associated with a minor respiratory infection (e.g., sore throat). Older children and teens are more likely to experience more severe symptoms of mono. In general, the older a person is when contracting the infection, the more severe and longer-lasting the symptoms are likely to be.

Fatigue is one of the chief symptoms that accompany mono. Initially, people may feel so tired that they struggle to get out of bed. However, over time, this fatigue gradually gets better. Other symptoms associated with mono include:

  • Fever
  • Headache
  • Loss of appetite
  • Night sweats
  • Skin rash (not usually itchy)
  • Abdominal pain
  • Soft, swollen spleen
  • Sore throat
  • Swollen lymph nodes in the neck and armpits
  • Swollen tonsils
  • Weakness

Symptoms typically appear between four and six weeks after exposure to the virus. Most symptoms disappear within a couple of weeks, although some (e.g., fatigue, swollen spleen) may linger. Mono does not usually pose a serious health risk and is almost never fatal.

Diagnosis methods for mononucleosis

o diagnose mononucleosis (mono), a physician may perform a complete physical examination and compile a thorough medical history. Generally, the presence of fever, sore throat and swollen lymph nodes for between one and four weeks is enough for a physician to suspect a diagnosis of mono. The physician may also press on the abdomen to look for signs of an enlarged liver or spleen and may look for signs of a skin rash.

A specific blood test called the monospot blood test may be performed to confirm the presence of a current mono infection. Other blood tests may indicate whether a person was ever previously exposed to the Epstein-Barr virus. A complete blood count (CBC) may also be used.

A throat culture is sometimes performed to rule out strep throat, which may sometimes accompany mono or may be confused with mono. It is important to identify strep throat infections since they require antibiotic treatment.

Patients with mono may undergo an ultrasound after symptoms have subsided. This is sometimes used to evaluate whether the spleen has returned to its normal size, before a patient is allowed to safely resume physical activity.

Treatment and prevention of mononucleosis

Usually, there is no medical treatment for mononucleosis (mono). In most cases, patients may be advised to get adequate rest and drink plenty of fluids. Antibiotics are not used because they are not effective against viral infections such as mono. Depending on the severity of the infection, it may take two to three months before a person is fully recovered.

However, antibiotics may be used to treat infections that sometimes accompany mono. These may include strep throat, sinus infection or an infection of the tonsils (tonsillitis). Some physicians prescribe corticosteroid medications to treat symptoms such as swelling of the throat and tonsils.

Self-care tips associated with mono include drinking plenty of water and fruit juices, gargling with salt water to relieve a sore throat and taking over-the-counter pain relievers. People should never take any medication without first consulting a physician. In particular, children should never be given aspirin, which can result in a rare but potentially fatal disorder known as Reye syndrome.

Proper rest is the key to recovery from mono. People who rush back to activity can trigger a relapse. For this reason, people are urged to avoid vigorous activity until a physician approves a return to such activity. In particular, it is important to avoid contact sports, because this increases the risk of a ruptured spleen.

Because mono is spread through saliva, people are urged to avoid certain types of contact with people who are infected with the Epstein-Barr virus. This includes avoiding kissing or sharing food, beverages, eating utensils and other personal items that may have come into contacted with the infected person’s mouth.

The length of time a person with mono is contagious is unclear, although it is believed to be for the duration of infection as well as some time afterward. That is why some preventive measures, such as avoiding open-mouth kissing, may be recommended for up to six months after infection to avoid its spread. People with mono are typically urged not to donate blood for at least six months after becoming ill. There is no vaccine currently available to prevent mono.

Questions for your doctor about mononucleosis

Preparing questions in advance can help patients to have more meaningful discussions with healthcare professionals regarding their conditions. Patients may wish to ask their doctor the following questions related to mononucleosis (mono):

  1. How will I know if I have mono and not just fatigue?
  2. How will you diagnose mono?
  3. What treatments do you recommend?
  4. Are there certain activities I should I avoid while I recover?
  5. How long will I need to rest or avoid physical activity?
  6. What symptoms may indicate a secondary infection due to my mono?
  7. For how long will I be contagious?
  8. If I’ve already been exposed to the virus that causes mono, under what circumstances might it reactivate and potentially spread to others?
  9. What steps should I take to make sure I do not spread this illness to others?
  10. Is there a way to find out if I’m carrying the Epstein-Barr virus?
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