Overview.
Infectious mononucleosis is a lymphoproliferative infection caused by EBV.
Typical manifestations include fever, symptoms of isthmus (e.g., sore throat), enlarged lymph nodes, hepatosplenomegaly, and rash.
Caused by EBV infection
Mainly symptomatic supportive treatment
Definition
Infectious mononucleosis is an infectious disease characterized by benign lymphocyte hyperplasia caused by acute infection with the Epstein-Barr Virus (EBV), which provides long-lasting immunity after a single episode of illness and rarely recurs.
EBV is a herpesvirus that is human lymphocyte-loving and is also the causative agent of nasopharyngeal carcinoma and certain lymphomas.
Incidence
Incidence
Epidemiologic data are not available in China.
It has been reported in the literature that the average incidence rate in 19 universities in the United States from 1971 to 1972 amounted to 840/100,000 students.
Regional distribution
The disease occurs in all parts of the world, mostly distributed, but can also cause epidemics. Epidemics may occur in areas with poor sanitation and overcrowding.
In China, the disease was first detected in Shantou, Guangdong in 1901, followed by epidemics in Fujian (1914), and successive epidemics in Tianjin, Beijing and Shanghai.
Time distribution
The disease can occur throughout the year, mostly in late fall and early winter.
Population distribution
The disease can occur in different races and genders.
There is not much difference between men and women in the incidence of the disease, generally the ratio of incidence of men and women is 3:2, and the incidence of women over 20 years of age is more than that of men.
Causes
Causes
Infectious mononucleosis is caused by EBV. The basic conditions leading to the epidemic are the following three aspects.
Source of infection
EBV carriers and patients with infectious mononucleosis are the source of infection for this disease.
Route of transmission
It is mainly transmitted through close oral contact, such as kissing, sharing utensils, chewing food and feeding infants, etc. It can also be transmitted through droplet transmission and occasionally through blood transfusion.
Susceptible people
The population is generally susceptible, but mainly occurs in children and adolescents, over 35 years of age is rare.
Pathogenesis
After entering the human body through the nose and mouth, EBV first invades the pharyngeal tonsils and infects the local B-lymphocytes, and at the same time reproduces in other salivary glands, such as the parotid gland, and discharges the EBV outwardly through the saliva, and then spreads to other parts of the body through the blood circulation and the lymph vessels to cause the disease.
Symptoms
The incubation period is usually 4 to 7 weeks in adults and 5 to 15 days in children, with varying degrees of urgency.
Prodromal symptoms
Before the appearance of typical symptoms, most patients may have weakness, headache, chills, nasal congestion, nausea, loss of appetite, mild diarrhea and other prodromal symptoms.
The duration of prodromal symptoms does not exceed 1 week.
Typical symptoms
Fever
Most patients have moderate fever, sometimes with high fever.
Most of them last for 5 to 10 days, and sometimes the low-grade fever may last for 1 month to several months.
The fever may be sudden or subside gradually.
Symptoms of Pharyngitis
The main symptoms are swelling of the pharynx, sore throat, and membranous covering of the tonsils.
In severe cases of pharyngeal swelling, there may be difficulty in breathing and swallowing.
Swollen lymph nodes
Enlargement of lymph nodes can occur throughout the body, most commonly in the neck, followed by the armpits and groin (thigh roots).
Enlarged lymph nodes appear as hard, painless, pushable lumps, mostly no more than 3 centimeters in diameter.
The enlarged lymph nodes return to normal several weeks after the fever subsides.
Liver and spleen enlargement
About half of the patients have moderate splenomegaly, with the spleen palpable under the ribs on the left side when lying on the right side and flexing the left lower limb, and with pain and tenderness on pressure.
Some patients have hepatomegaly, with the liver palpable under the right rib cage, and some have mild yellowing of the skin and sclera (whites of the eyes).
Skin Rash
About 1/3 of the patients will develop a rash, which varies in shape and is often a papular or maculopapular rash that occurs on the trunk and extremities. It usually lasts about 1 week and subsides without flaking or hyperpigmentation.
Some patients may have multiple pinpoint-sized bleeding dots on the palate in the mouth, which may occasionally fuse to form a large area and last for 3 to 4 days.
Complications
A small number of patients can cause serious complications.
Splenic rupture: at first, there is pain, pressure, rebound pain and muscle tension in the left upper abdomen, which gradually spreads to the whole abdomen.
Myocarditis: there may be palpitations, shortness of breath, chest tightness, and discomfort in the precordial area.
Autoimmune hemolytic anemia: there may be chills, high fever, low back pain, vomiting, diarrhea and other hemolytic symptoms.
Thrombocytopenic purpura: there may be dark purple plaques of varying sizes on the skin and mucous membranes.
Neurologic complications: such as meningitis, meningoencephalitis, etc., there may be severe headache, vomiting, neck stiffness and other symptoms of meningeal irritation.
Phagocytic syndrome: there may be systemic symptoms such as high fever, chills, night sweats, loss of appetite, weight loss, and joint and muscle aches.
Liver failure: there may be fatigue, loss of appetite, abdominal distension, nausea, vomiting, yellow staining of the skin and sclera (white of the eyes) which gradually deepens in a short period of time.
Consultation
Department of Medicine
Department of Infection
For symptoms such as fever, sore throat, swollen lymph nodes, rash, etc., it is recommended to consult the Department of Infectious Diseases or the Fever Clinic.
Emergency Department
In case of emergency such as high fever, convulsions, respiratory distress, etc., it is recommended to go to the Emergency Department immediately.
Pediatrics
Children with the above symptoms can also go to the Pediatrics Department.
Preparation
How to get to the doctor: registration, preparation of documents, common problems
Tips for your visit to the doctor
During the consultation, abdominal ultrasound and other tests may be required, so it is recommended to wear loose clothing.
Avoid taking fever-reducing medication or antibiotics on your own, as this may affect the doctor’s judgment of your condition. For patients with high fever, physical cooling can be done first, such as applying cold compresses to the forehead and wiping hands, feet and armpits with warm water.
Preparation Checklist for Doctor’s Visit
Symptom Checklist
Pay particular attention to the time of onset of symptoms, special manifestations, etc.
Is there fever? What is the highest degree?
Is there a sore throat? How long has it been present?
Is there a rash?
Is there a palpable neck swelling? Is the swelling accompanied by pain?
Is an abdominal mass palpable in the right upper abdomen?
Medical History Checklist
Any contact with a patient with infectious mononucleosis?
Checklist
Test results from the last 6 months, which can be brought to the doctor’s office
Laboratory tests: blood count
Imaging tests: abdominal ultrasound
Medication List
Medication used in the last 3 months, bring the box or package with you if available
Antipyretics: ibuprofen, acetaminophen
Antivirals: acyclovir, ganciclovir
Diagnosis
Diagnosis is based on
Medical history
History of contact with EBV carriers or patients with infectious mononucleosis.
Clinical manifestations
There are typical manifestations such as fever, symptoms of pharyngitis (e.g., sore throat, pharyngeal swelling), enlarged lymph nodes, hepatosplenomegaly, and rash.
Laboratory Tests
Routine blood tests
White blood cell count, lymphocyte and monocyte ratio, as well as the presence and percentage of anomalous lymphocytes (lymphocytes with abnormal morphology) can be used to determine the presence or absence of infection and to assist in the diagnosis.
An elevated white blood cell count and a high percentage of lymphocytes, which may exceed 50%, suggests the presence of an infection and the possibility of the disease.
Heterogeneous lymphocytes over 10% are diagnostic.
Biochemical tests
Elevated aminotransferases are seen.
Serologic tests
EBV antibody test
The presence or absence of IgM and IgG antibodies to viral capsid antigen (VCA) and anti-EBV nuclear antigen antibody (anti-EBNA) IgG in serum can be detected to clarify whether the patient is infected with EBV.
If anti-VCA IgM is positive, anti-VCA IgG is negative and anti-EBNA IgG is negative in the antibody test, it suggests initial infection with EBV.
If anti-VCA IgG is positive and anti-EBNA IgG is negative, it suggests recent EBV infection.
Positive anti-VCA IgG and positive anti-EBNA IgG suggests previous infection with EBV.
Heterophilic agglutination test
IgM heterophilic antibodies are present in the patient’s serum and are able to agglutinate sheep or horse erythrocytes.
The agglutination value is above 1:64 and remains positive after absorption by guinea pigs, which has diagnostic value.
The test can also be positive in healthy people and patients with other diseases, and needs to be combined with other tests for differentiation.
Viral nucleic acid test
Blood, urine and other body fluids are taken as specimens, and polymerase chain reaction (PCR) technology is applied to amplify viral DNA fragments for nucleic acid detection.
The presence of EBV DNA in the specimen will help to confirm the diagnosis.
Differential Diagnosis
Herpes pharyngitis
Similarities: Both may have fever and symptoms of pharyngitis such as sore throat and pharyngeal swelling.
Differences: Herpes pharyngitis is mainly caused by coxsackievirus, without symptoms such as enlarged lymph nodes, liver and spleen, etc. It can be differentiated by combining with medical history and laboratory tests.
Exudative tonsillitis caused by streptococcus.
Similarity: both may have fever, loss of appetite, malaise, sore throat, pharyngeal swelling and other symptoms.
Differences: Exudative tonsillitis caused by streptococcus is mainly caused by Streptococcus b hemolyticus, without symptoms such as enlarged lymph nodes, liver and spleen, etc. It can be differentiated by history and laboratory examination.
Lymph node tuberculosis
Similarity: both may have enlarged lymph nodes.
Difference: Lymph node tuberculosis is caused by Mycobacterium tuberculosis, the enlarged lymph nodes can be fused with each other to form a large mass, there is no rash and other symptoms, combined with the history, laboratory tests can be differentiated.
Lymphocytic leukemia
Similarities: both may have fatigue, fever, enlarged lymph nodes, liver and spleen, skin rash, etc.
Differences: Lymphoblastic leukemia is a blood tumor without viral infection and cannot be cured by itself; it can be differentiated by history and laboratory tests.
Viral hepatitis
Similarities: Both may have fever, malaise, loss of appetite, nausea, diarrhea, yellow staining of the skin and sclera (white of the eye).
Differences: Viral hepatitis is caused by hepatitis virus, mainly manifested as digestive symptoms, no lymph node enlargement, etc. It can be distinguished from viral hepatitis by combining with medical history and laboratory examination.
Treatment
Symptomatic supportive treatment
Rest: Patients should take bed rest to reduce physical exertion and promote disease recovery. Those with splenomegaly should reduce their activities to prevent splenic rupture.
Reasonable diet: Drink plenty of water and eat a light, high-calorie diet.
Antipyretic: For those with fever, physical methods or antipyretic drugs are needed to lower the temperature.
Analgesia: For sore throat, analgesics are needed.
Hepatoprotective: For severe liver damage, hepatoprotective drugs should be applied.
Glucocorticoid therapy: patients with myocarditis, severe pharyngeal edema, autoimmune hemolytic anemia, neurological complications, etc., need to take oral prednisone and other glucocorticoid therapy.
Antiviral therapy
Antiviral therapy has a limited effect on the improvement of symptoms and the overall course of the disease, and is therefore generally not routinely used.
Special note: All medications should be used according to the doctor’s instructions, avoiding self-medication or changes in dosage.
Prognosis
Cure
The disease is self-limiting and has a favorable prognosis, with a mortality rate of 1% to 2%.
Most of the cases are cured in 2 to 3 weeks, a few cases may last for 1 month or several months, and some cases may be prolonged for several years.
The disease occasionally relapses, and the relapses are mild.
Dangers
Symptoms such as fever and sore throat occur, affecting normal life and work.
A few may cause serious complications such as splenic rupture, myocarditis, autoimmune hemolytic anemia, thrombocytopenic purpura, meningitis, meningoencephalitis, hemophagocytic syndrome, and liver failure, which can be life-threatening.
The disease is contagious and may be transmitted to others.
Daily
Daily Management
Dietary management
Drink plenty of water.
A high-calorie, light diet with less oil, salt and sugar is recommended.
Avoid oily, cold, spicy and stimulating foods, such as fatty meat, sashimi, chili peppers, onions, ginger and garlic.
Eat more foods rich in vitamins, such as fresh vegetables, melons and fruits.
Prohibit the consumption of alcohol.
Reduce contagion
Avoid kissing and sharing utensils with others.
Avoid chewing food to feed babies.
Life management
Take rest and avoid exertion.
Maintain sufficient sleep time and avoid staying up late.
Quit smoking.
Psychological support
Pay attention to mental health, release pressure in time, avoid anxiety, depression, excessive tension and other bad emotions.
Patients and their families should correctly understand infectious mononucleosis, change the wrong perception of the disease, and establish confidence in curing the disease.
Prevention
There is currently no vaccine, the following measures can be taken for prevention.
Avoid close contact with infectious mononucleosis patients.
Avoid kissing and sharing utensils with others when there is a local epidemic of infectious mononucleosis.
Exercise more, eat a healthy diet and strengthen your immunity.