Epstein-Barr virus and cytomegalovirus infection — branching viva

Branching structured-oral viva on EBV and CMV infection: the pathophysiology of EBV B-cell tropism and the CD8 T-cell response, the classic mononucleosis triad and the amoxicillin rash, the 21-day diagnostic window and valganciclovir treatment for congenital CMV, the splenic-rupture and return-to-play rules, CMV in the immunocompromised host, and the EBV-lymphoproliferation and EBV-multiple-sclerosis associations.

branching clinical structured oral5 min readVerification in progress

Prompt

You are the general paediatric registrar in the emergency department. A 16-year-old is brought in with a week of fever, a severe sore throat, marked fatigue and posterior cervical lymphadenopathy; her tonsils are encroaching on the airway and her spleen is palpable. A Monospot is positive. She was started on oral amoxicillin by her GP two days ago and a confluent rash has appeared. The examiner asks you to take the candidate through the diagnosis, the rash, the pathophysiology, the management and the complications, and then to contrast this with a neonate who presents with congenital CMV.

Opening question

Examiner: Take me through this adolescent. What is the diagnosis, and what is the significance of the rash? [2]

Candidate: The diagnosis is Epstein-Barr virus infectious mononucleosis. The triad of fever, exudative pharyngitis and posterior cervical lymphadenopathy, with splenomegaly and a positive Monospot, is classic. The maculopapular rash that appeared after amoxicillin is an EBV-driven immune phenomenon rather than a true penicillin allergy — it develops in nearly all patients with EBV mononucleosis given ampicillin or amoxicillin and resolves when the antibiotic stops. The clinical error was giving the antibiotic at all, because the sore throat is viral. [6] [2]

Examiner: Why does EBV produce this illness at all? [1]

Candidate: EBV enters through the oropharynx, infects the epithelium, and then infects B cells via the CD21 complement receptor. It drives polyclonal B-cell activation and establishes lifelong latency in memory B cells. But the symptoms of mononucleosis are largely the host CD8 cytotoxic T-cell response to those infected B cells — the atypical lymphocytes on the blood film are reactive T cells, not infected B cells. The illness is the immune response. [1] [4]

Paediatrics Fellowship Pro

You have read the opening of this viva. The complete unit — every section and its primary-source references — is part of the Paediatrics Fellowship fellowship atlas.

References9Show ledger

[1]Cohen JI Epstein-Barr virus infection. N Engl J Med, 2000.PMID 10944566
[2]Ebell MH Epstein-Barr virus infectious mononucleosis. Am Fam Physician, 2004.PMID 15508538
[4]Taylor GS; Long HM; Brooks JM; Rickinson AB; Hislop AD The immunology of Epstein-Barr virus-induced disease. Annu Rev Immunol, 2015.PMID 25706097
[6]Abreu A; Nunes S; Botelho C Eosinophilia in Amoxicillin-Induced Rash in Infectious Mononucleosis. Cureus, 2023.PMID 36756024
[7]Putukian M; McGrew CA; Benjamin HJ; et al American Medical Society for Sports Medicine Position Statement: Mononucleosis and Athletic Participation. Clin J Sport Med, 2023.PMID 37186809
[8]Kimberlin DW; Jester PM; Sánchez PJ; Ahmed A; et al Valganciclovir for symptomatic congenital cytomegalovirus disease. N Engl J Med, 2015.PMID 25738669
[9]Rawlinson WD; Boppana SB; Fowler KB; Kimberlin DW; et al Congenital cytomegalovirus infection in pregnancy and the neonate: consensus recommendations for prevention, diagnosis, and therapy. Lancet Infect Dis, 2017.PMID 28291720
[10]Fowler KB; Boppana SB Congenital cytomegalovirus infection. Semin Perinatol, 2018.PMID 29503048
[11]Boppana SB; Ross SA; Shimamura M; Palmer AL; et al Saliva polymerase-chain-reaction assay for cytomegalovirus screening in newborns. N Engl J Med, 2011.PMID 21631323