EBV

Question 1

What is the most common cause of infectious mononucleosis?

Answer 1

Epstein-Barr virus (EBV).

Infectious mononucleosis (IM) is a viral syndrome most commonly due to Epstein-Barr virus, with manifestations that commonly include fever, fatigue, exudative pharyngitis, lymphadenopathy, and hepatosplenomegaly. Liver function test results may be mildly elevated. Patients with IM may develop an erythematous exanthematous rash, which is usually maculopapular, urticarial, or morbilliform and most often erupts after inappropriate administration of amoxicillin or ampicillin. The etiology of this well-known phenomenon is unclear, although it may be an immune-mediated response to circulating antibodies against penicillin derivatives. The rash is not considered a true antibiotic allergy and will resolve spontaneously over time with observation and supportive care.

Question 2

To which virus family does Epstein-Barr virus belong?

Answer 2

Herpesvirus family (Herpesviridae)

Question 3

What type of genetic material does EBV have?

Answer 3

Double-stranded DNA (dsDNA)

Question 4

Is Epstein-Barr virus enveloped or non-enveloped?

Answer 4

Enveloped

Question 5

How is Epstein-Barr virus primarily transmitted?

Answer 5

Through saliva (‘kissing disease’)

Question 6

Which cell surface receptor does EBV bind to?

Answer 6

CD21 on B cells

Question 7

What glycoprotein of EBV binds to CD21?

Answer 7

GP350

Question 8

What are the classic symptoms of infectious mononucleosis?

Answer 8

• Severe fatigue
• Fever
• Pharyngitis
• Tonsillar exudates
• Tender posterior cervical lymphadenopathy

Question 9

What type of immune response is seen in EBV infection?

Answer 9

Peripheral lymphocytosis with reactive lymphocytes (Downy cells).

Question 10

What are Downy cells?

Answer 10

Atypical lymphocytes with abundant basophilic cytoplasm seen in EBV infection.

Question 11

What complications arise from lymphoid proliferation in EBV infection?

Answer 11

Splenomegaly and enlarged lymph nodes.

Question 12

Why would LFTs be checked when a patient has mononucleosis?

Answer 12

Transient hepatitis.

Question 13

Where does Epstein-Barr virus remain latent?

Answer 13

In B cells.

Question 14

Which malignancies are associated with Epstein-Barr virus?

Answer 14

• Hodgkin lymphoma
• Burkitt lymphoma
• non-Hodgkin lymphoma
• nasopharyngeal carcinoma
• oral hairy leukoplakia

Question 15

What are the histological features of Hodgkin lymphoma?

Answer 15

Reed-Sternberg cells (large abnormal B cells with owl-eye nuclei).

Question 16

What is endemic Burkitt lymphoma?

Answer 16

A subtype of Burkitt lymphoma in children from equatorial Africa, often presenting with jaw swelling.

Question 17

Which malignancy is particularly common in Southeast Asia and strongly associated with EBV?

Answer 17

Nasopharyngeal carcinoma.

Question 18

What condition is associated with EBV infection in HIV patients?

Answer 18

Oral hairy leukoplakia.

Question 19

What test is commonly used for rapid diagnosis of infectious mononucleosis?

Answer 19

Monospot test (detects heterophile IgM antibodies).

Question 20

Why is the Monospot test no longer recommended by the CDC?

Answer 20

Due to low sensitivity and specificity.

Question 21

What is the gold standard test for diagnosing EBV infection?

Answer 21

Serum testing for Epstein-Barr virus-specific antibodies.

Question 22

What is the clinical course for mononucleosis and how does this evolve overtime?

Answer 22

Most patients with IM will have an uncomplicated course and symptoms will resolve spontaneously within weeks of onset. However, persistent fatigue is common and may exist for months (with some patients experiencing chronic fatigue for >6 months). Women and individuals with preexisting mood disorders may be at increased risk for prolonged fatigue.

Question 23

Is mononucleosis considered to be an STI?

Answer 23

No. Although Epstein-Barr virus can be isolated in cervical discharge and semen, there is no evidence that these fluids are more contagious than saliva, and close sexual contacts are not considered to be at higher risk of infection than other contacts. Testing is not indicated for any contact who is asymptomatic.

Question 24

Why should patients with infectious mononucleosis avoid contact sports?

Answer 24

Risk of splenic rupture due to splenomegaly.

Question 25

How long should patients avoid contact sports after EBV infection?

Answer 25

At least 4 weeks (3 weeks for regular sports)

Question 26

What happens if a patient with EBV is mistakenly treated with amoxicillin or penicillin?

Answer 26

They develop a maculopapular rash. This rash rash is commonly described as a diffuse, erythematous, blanching, maculopapular rash is seen on the chest, abdomen, and extremities. The rash is not considered a true antibiotic allergy and will resolve spontaneously over time with observation and supportive care.

Question 27

Why do patients with EBV develop a rash after receiving amoxicillin?

Answer 27

Immune-mediated reaction due to abnormal immune response to antibiotics. This rash rash is commonly described as a diffuse, erythematous, blanching, maculopapular rash is seen on the chest, abdomen, and extremities. The rash is not considered a true antibiotic allergy and will resolve spontaneously over time with observation and supportive care. The rash does not correlate with increase risk of spreading this infection.

Question 28

Are corticosteroids or antihistamines used to treat the rash that develops after administering penicillin in an EBV infection, when would these be indicated?

Answer 28

The rash will not improve if treated with medications used to combat allergic reactions (eg, corticosteroids, antihistamines). The rare occasions in which corticosteroids are indicated in the management of IM include severe sequelae such as hemolytic anemia or airway obstruction.