Mononucleosis is caused most commonly by the Epstein-Barr virus. It is characterized by fever, sore throat, and swollen lymph nodes. While symptoms usually clear within a few weeks, fatigue can sometimes last for months. Diagnosis involves physical exam findings along with blood tests detecting heterophile antibodies or EBV antibodies. Treatment is supportive with rest, fluids, and over-the-counter medications for fever and pain. Complications are rare but may include spleen rupture or neurological issues. Prevention involves good hygiene and avoiding sharing foods or drinks with those exhibiting viral symptoms.

1. Prepared by: Dr. Zahra HasanAlali
Medical intern
Supervised by: Dr. Mohammed Ali Almatar

2. OBJECTIVES:
Definition of
Mononucleosis
Epidemiology of
Mononucleosis
Causes of
Mononucleosis
Pathophysiology
Clinical picture
Diagnosis of
mononucleosis
Treatment of
mononucleosis
Prevention of
mononucleosis

3. DEFINITION & EPIDEMIOLOGY

4. DEFINITION OF MONONUCLEOSIS:
• Infectious mononucleosis is an infectious disease characterized by a triad
of fever, tonsillar pharyngitis and lymphadenopathy.
• It was formerly known as glandular fever, but this term was changed to
infectious mononucleosis.
• Epstein-Barr virus (EBV) is the most common cause of infectious
mononucleosis, but other viruses can also cause this disease.
UP TO DATE

5. EPIDEMIOLOGYOF MONONUCLEOSIS
• The worldwide incidence of infectious mononucleosis is unknown, but in
developing countries, 90% of children experience an asymptomatic
Epstein-Barr virus infection.
Primary EBV infection in Saudi
Arabia occurs more frequently in
the younger age groups in early
childhood. Non-typical
presentation occur more
frequently in infants. While
adolescents are less commonly
affected by primary EBV.
Zaki A. Primary Epstein-Barr Virus Infection in Healthy Children in Saudi Arabia: A Single
Hospital-Based Study. J Trop Pediatr. 2021 Jan 29;67(1):fmaa121. doi: 10.1093/tropej/fmaa121.
PMID: 33351945.

6. CAUSES

7. CAUSES OF MONONUCLEOSIS:
• Mononucleosis is caused by 2 members of the herpes simplex family:
Epstein-Barr virus Cytomegalovirus
This variant is milder
Elana Pearl Ben-Joseph. "How Long Is Mono Contagious?". Kidshealth.org. Archived from the original on 2016-11-19.

8. Epstein-Barr virus (EBV)
• 90% of cases of infectious mononucleosis are caused by EBV.
• It is one of the most common viruses throughout the world.
• EBV is not highly contagious.
• It can only be contracted through direct contact with an infected person's saliva,
such as through kissing or sharing toothbrushes.
• About 95% of the population has been exposed to EBV by the age of 40, but only
about 40% of exposed adults develop infectious mononucleosis.
• Incubation period is between 4-8 weeks.
Elana Pearl Ben-Joseph. "How Long Is Mono Contagious?". Kidshealth.org. Archived from the original on 2016-11-19.

9. CYTOMEGALOVIRUS (CMV)
• About 5–7% of cases of infectious mononucleosis is caused by CMV.
• CMV is found in body fluids including saliva, urine, blood, and tears.
• A person becomes infected with this virus by direct contact with infected body
fluids.
• Cytomegalovirus is mostly transmitted through kissing and sexual intercourse.
• It can also be transferred from an infected mother to her unborn child.
Elana Pearl Ben-Joseph. "How Long Is Mono Contagious?". Kidshealth.org. Archived from the original on 2016-11-19.

10. CYTOMEGALOVIRUS (CMV) Cont…
• This virus is often "silent" because the signs and symptoms cannot be felt by the
person infected.
• However, it can cause life-threatening illness in:
• Infants.
• Patients with HIV.
• Transplant recipients.
• Patients with weak immune systems.
• Once a person becomes infected with cytomegalovirus, the virus stays in their
body fluids throughout the person's lifetime.
Elana Pearl Ben-Joseph. "How Long Is Mono Contagious?". Kidshealth.org. Archived from the original on 2016-11-19.

11. PATHOPHYSIOLOGY

12. PATHOPHYSIOLOGY EBV enucleation on
the mucosa of the
oral cavity
Virus starts
replicating in the
cells especially B
cells of lymphoid
tissue
virus spreads through the
lymphatic system and RES
causing lymphadenopathy and
hepato-splenomegaly
Morphologically abnormal
(atypical) lymphocytes develop
called Downey cells. mainly
from CD8+ T cells that respond
to the infection.
PRIMARY
EXPOSURE
American Society of Heamtology

13. infectious Mononucleosis(Mono)By Kenneth M. Kaye , MD, Harvard Medical School| Modified
Sep 2022

14. This is Downey’s cell. This
type of reactive
lymphocyte increases in
EBV infections.
• Downey type II cell is
characterized by:
1.Deeply basophilic
abundant cytoplasm
“BLUE”
2.The cell appears to hug its
surrounding cells
American Society of Heamtology

15. PATHOPHYSIOLOGY Cont…
• When the infection is acute (recent onset, instead of chronic) 
heterophile antibodies are produced.
• CMV, Adenovirus and Toxoplasma gondii infections can cause symptoms
similar to infectious mononucleosis, but heterophile antibody test will be
negative.
infectious Mononucleosis(Mono)By Kenneth M. Kaye , MD, Harvard Medical School| Modified
Sep 2022

16. CLINICAL PICTURE

17. GENERAL EXAMINATION (S&S)
FEVER ANOREXIA
MALAISE &
WEAKNESS
HEADACHE
GENERALIZED
LYMPADENOPATHY
HEPATO-
SPLENOMEGALY
UP TO DATE

18. LOCAL EXAMINATION (SYMPTOMS)
SORETHROAT
REFERRED
OTALGIA
DYSPHAGIA
UP TO DATE

19. LOCAL EXAMINATION (SIGNS)
Pharyngitis, ulcers covered by
false membrane
Palatal petechiae (early)
UP TO DATE

20. C/P DIFFERS ACCORDINGTO AGE:
• In children before puberty  the disease typically only produces flu-like
symptoms
• In adolescence and young adulthood  the disease presents with a
characteristic triad of
1. Fever – mild lasting 2 weeks
2. Sore throat – severe lasting for 3–5 days.
3. Swollen glands – mobile; usually located around the back of the neck (posterior
cervical lymph nodes) and sometimes throughout the body.
Cohen JI (2008). "Epstein-Barr Infections, Including Infectious Mononucleosis". In Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo
DL, Jameson JL, Loscalzo J (eds.). Harrison's principles of internal medicine (17th ed.). New York: McGraw-Hill Medical Publishing
Division. pp. 380–91.

21. PROGRESSIONOFTHE C/P
• Symptoms most often disappear after about 2–4 weeks. However, fatigue
and a general feeling of being unwell (malaise) may sometimes last for
months.
• Caution!!!
Do not give a patient suspected of mononucleosis ampicillin or
amoxicillin because it's associated with the development of a generalized
itchy maculopapular rash.
Cohen JI (2008). "Epstein-Barr Infections, Including Infectious Mononucleosis". In Kasper
DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson JL, Loscalzo J (eds.). Harrison's
principles of internal medicine (17th ed.). New York: McGraw-Hill Medical Publishing Division.
pp. 380–91.

22. DIAGNOSIS

23. DIAGNOSIS OF MONONUCLEOSIS
HISTORYTAKING
PHYSICAL
EXAMINATION
INVESTIGATIONS

24. INVESTIGATIONS:
Heterophile Ab testing Serological testing
• Cheap
• Considered a screening test
• Easy to perform
• Results come back in 1 day
• Not specific! (however if the
C/P is typical for MONO and
heterophile Ab’s are +ve 
no need for further testing)
• Relatively more expensive
• Results take longer to come
back
• More accurate
(confirmatory)
• detect antibodies directed
against EBV.
• IgG  past infection
• IgM  recent infection
JOHNS HOPKINGS MEDICINE

25. INVESTIGATIONS:
• Epstein–Barr nuclear antigen detection  EBV nuclear Ag is not normally
recognizable until several weeks into the disease and is useful for distinguishing
between a recent-onset of infectious mononucleosis and symptoms caused by a
previous infection.
• LIVER FUNCTIONTEST  shows elevated transaminases in 50% of cases
• Peripheral blood smear  .50% lymphocytes with at least 10% atypical
lymphocytes. “lymphocytosis with atypical lymphocytes”
JOHNS HOPKINGS MEDICINE

26. LYMPHADENOPATHY
A case
comes with
a triad of:
WHAT IS YOUR DIFFERENTIAL DIAGNOSIS?

27. DIFFERENTIAL DIAGNOSIS
1. INFECTIONS:
• BACTERIAL (Group A beta hemolytic streptococci, Arcanobacterium haemolyticum).
• VIRAL (EBV, acute HIV, HHV-6, HHV-7).
• PROTOZOAL (Toxoplasma gondii)
2. DRUGS:
• ANTICONVULSANTS (phenytoin, carbamazepine)
• ANTIBIOTICS (Isoniazid, Minocycline)
3. MALIGNANCY
• Most importantly lymphoma.
4. Other causes of generalized lymphadenopathy (metabolic, etc…)

28. COMPLICATIONSOF MONONUCLEOSIS
1. Ruptured spleen
2. Kidney inflammation
3. Hemolytic anemia,Thrombocytopenia.
4. Nervous system problems, such as encephalitis, meningitis, and other
conditions
5. Inflammation of the heart muscle
6. Heart rhythm problems
7. Obstruction of the upper airways
8. EBV has also been implicated in causing lymphomas and nasopharyngeal
cancers
NOTETHAT COMPLICATIONS OF
MONONUCLEOSIS ARE RARE
UP TO DATE

29. TREATMENT

30. TREATMENT OF MONONUCLEOSIS
• mononucleosis is generally self-limiting, so only symptomatic or supportive
treatments are used.
• Treatment mainly involves:
1. Bed rest.
2. Avoiding sports
3. Good nutrition.
4. Drinking plenty of fluids.
5. Treating secondary infections.
6. Symptomatic treatment:
• Fever and pain  NSAIDs
• To reduce upper respiratory tract obstruction  corticosteroids “controversial”
UP TO DATE

31. TREATMENT OF MONONUCLEOSIS
• Intravenous corticosteroids are not recommended for routine use but may be
useful if there is:
• Risk of airway obstruction.
• Very low platelet count.
• Hemolytic anemia.
• There is no evidence that supports the use of antivirals like Acyclovir.
• Avoid using ampicillin and amoxicillin.
UP TO DATE

32. PREVENTION

33. PREVENTION
• There’s no vaccine for mono.
• The best way to prevent getting the viruses that
cause mono is by:
1. practicing good hygiene.
2. Don’t share foods, drinks or bodily fluids with
someone who has mono or any signs of viral
illness, like fever, cough, sore throat or fatigue
Zaki A. Primary Epstein-Barr Virus Infection in Healthy Children in Saudi Arabia: A Single Hospital-Based
Study. J Trop Pediatr. 2021 Jan 29;67(1):fmaa121. doi: 10.1093/tropej/fmaa121. PMID: 33351945.