CH7- Viral Infections - The Herp Flashcards
What % of the US is infected by HHV6 and 7 by the age of 5?
90%
Most HHV6/7 infections are asymptomatic, but if it is symptomatic, what are the 2 parts of presentation?
What are the 3 names?
Which virus more often causes it?
Presents as:
- Febrile
- Erythematous maculopapular eruption
Names:
- Roseola
- Exanthema subitum
- Sixth disease
More often HHV6, but may also be caused by HHV7
HHV6/7 may replicate in which tissue and establish latency in which cell type?
salivary glands…CD4+ Tcells
What is the major cell of latency for HHV8? What is the most common mode of transmission?
Circulating B-lymphocytes…male-to-male sexual contact
Which virus is assocated with Castleman disease?
HHV8
What is the most common site for latency for HSV1?
Trigeminal ganglion (other sites: nodose ganglion of the vagus nerve, dorsal root ganglia, and brain)
What % of the population is estimated to asymptomatically shed HSV1 every month?
70%
Age of initial HSV1 infection:
early age exhibits:
later in life:
early age exhibits: gingivostomatitis
later in life: pharyngotonsillitis
HSV2 infection is associated with a 2x increased risk for which other virus?
HIV
More than 15% of cases of erythema multiforme are preceded by a symptomatic recurrence of WHICH VIRUS? 3 to 10 days earlier
HSV (1 or 2? assuming 1?) some investigators believe that up to 60% of mucosal erythema multiforme may be triggered
What is the expected age range for Acute herpetic gingivostomatitis (primary herpes)?
Most affected individuals are between the ages of 6 months and 5 years, with the peak prevalence occurring between 2 and 3 years of age. However, occasional cases have been reported in patients over 60 years of age.
What 2 conditions can pharyngotonsillitis of primary HSV1 (or2) infection closely resemble in a young adult?
strep throat or mono
What is the alternate term for herpetic whitlow?
herpetic paronychia (para = around, onyx = nail)
What are three conditions that can predispose a patient to eczema herpeticum?
Which herpes virus causes this?
What is the alternate name for this?
Eczema, pemphigus, Darier disease
HSV-1 or 2
Kaposi varicelliform eruption (confusing name eh?)
What virus often co-infects with HSV-1 in persistent oral ulcers of AIDS patients (or immunocompromised pts in general)?
CMV
This term refers to free-floating epithelial cells in any intraepithelial vesicle and is not specific for herpes.)
Tzanck cell
What is the term for nuclear elargement in HSV histology?
ballooning degeneration
What are the 3 M’s of HSV histology?
Margination: condensation of chromatin around the periphery of the nucleus
Multinucleated: fusion between adjacent cells
Molding: cellular/nuclear (not in Neville)
What is the traditional method of diagnosis for HSV?
viral isolation collected from fluid of intact vesicles
but contamination from normal HSV shedding and 2 week culture are significant down sides
Ok, so culture of HSV takes 2 weeks, you decide to do a cytologic smear. What other virus has similar features to HSV and therefore is excluded based on clinical signs?
VZV
Primary herpetic gingivostomatitis treatment?
Within first 3 days: Acyclovir suspension. rinse-and-swallow 5x/day for 5 days
What are 3 supplemental medications for primary gingivostomatitis? (besides acyclovir)
- dyclonine hydrochloride spray,
- tetracaine hydrochloride lollipops (prepared by a compounding pharmacist)
- NSAIDs
- chlorhexidine (mentioned separately, no clinical trials done, but may work synergistically with acyclovir)
What are two reasons to avoid viscous lidocaine and topical benzocaine use in children?
- lidocaine-induced seizures in children
2. topical benzocaine and methemoglobinemia
Which medication has been shown to reduce pain by 1 day for herpes labialis?
penciclovir cream
What is the best treatment for HSV, CMV coinfected ulcers?
ganciclovir. (foscarnet IV used in refractory situations)
Ok, lets get this straight. Initial presentation of HHV3 is called:
recurrence due to latency is called:
Initial: varicella (chickenpox)
recurrence: herpes zoster
“Dew drop on a rose pedal”
primary VZV infection: vesicle surrounded by a zone of erythema
What is a good way to distinguish gingival lesions of VZV from HSV?
VZV typically painless
How does the presence of oral lesions in VZV relate to severity of infection?
Mild severity +/- oral lesions.
Sever ++ oral lesions
(patients with severe infections almost always have oral ulcerations, often numbering up to 30 and persisting for 5 to 10 days)
What are the 3 most frequent complications with childhood VZV infection?
- Secondary skin infections (grp a, Beta-heme strep progress to necrotizing fasciitis, septecemia, toxic shock syndrome)
- encephilitis
- pneumonia
What public educational intervention has helped lessen life-threatening complications of VZV infection?
decreased use of Aspirin in children (Reye syndrome: acute encephalopathy, liver failure, and other major organ damage)
(Though aspirin is approved for use in children older than age 3, children and teenagers recovering from chickenpox or flu-like symptoms should never take aspirin.
What is increased risk of death in adults who contract VZV? What is it primarily caused by?
The risk of death is reported to be 15 times greater in adults compared with children, mostly because of an increased prevalence of encephalitis.
What is the most definitive method for VZV diagnosis?
PCR on tissue obtained from the base of a lesion
What are 2 non-recommended medications for initial VZV infection?
- Diphenhydramine lotion (toxicity 2/2 percutaneous absorption)
- Aspirin (Reye Syndrome) / other NSAIDS (increased risk for severe skin and soft tissue
complications)
What is the Vericella vaccine paired with now?
MMR (so now its MMRV)
Where does VZV establish latency?
dorsal root ganglia
Herpes zoster occurs during the lifetime of approximately what % range of individuals?
33% - 50% (Herpes zoster occurs during the lifetime of approximately one in three individuals and as many as 50% of individuals who live to 85 years of age will be affected at sometime) yeah, im confused, but this card is just for perspective
Can the VZV vaccine present as herpes zoster later in life?
Yes. Risk is much lower than wild type VZV though
What is dermatomal pain without development
of a rash in herpes zoster called?
zoster sine herpete
What are 5 possible tooth manifestations as a consequence of herpes zoster infection?
- pulpitis
- pulpal necrosis
- pulpal calcification
- root resorption
- Bone necrosis (tooth loss)
What is the term for herpes zoster on the nasociliary branch (tip of the nose) of the trigeminal nerve? What is at risk for sever infection in this circumstance?
Hutchinson sign…possible severe ocular infection (mandatory referral to ophthalmologist)
Reactivation of VZV in WHICH ganglion may
cause Ramsay Hunt syndrome?
the geniculate ganglion
A potentially fatal ischemic stroke syndrome, termed __________ may develop weeks to months after resolution of a zoster rash involving the trigeminal nerve distribution.
Granulomatous angiitis
So gnarly. (This condition appears to result from direct extension of VZV and associated inflammation from the trigeminal ganglion to the internal carotid artery)
Herpes zoster primary and supportive therapy:
Primary: Prompt therapy with antiviral medications, such as acyclovir, valacyclovir, and famciclovir
Supportive: diphenhydramine and non-aspirin antipyretics
What is the age eligibility for the herpes zoster vaccine?
FDA approved 50 years or older, but due to shortages, CDC recommends 60 years or older
(interesting! Zostavax contains the same live, attenuated strain of VZV used in the varicella vaccines; however, it is 14 times more potent than Varivax, the monovalent varicella vaccine)
Similar Mono symptoms can be produced by what three pathogens?
- CMV
- HIV
- Toxoplasma gondii
What are the 3 main malignancies associated with EBV?
- Burkitt lymphoma
- Nasopharyngeal carcinoma
- Salivary lymphoepithelial carcinoma
aside: some gastric carcinomas, possibly breast and
hepatocellular carcinomas, and occasional smooth muscle tumors.
Which virus? hemophagocytic lymphohistiocytosis appears to be caused by massive activation of T lymphocytes and histiocytes and is often fatal without prompt treatment
EBV
Can add this one to the palsy ddx:
Enlargement of parotid lymphoid tissue rarely has
been reported and can be associated with facial nerve palsy.
WHICH virus?
EBV
5 Head&Neck/Oral manifestations of Mono. Go
- Bilateral LAD
- Facial nerve palsy 2/2 parotid LN swelling
- tonsilar enlargment (oropharyngeal/lingual) (+/- exudates, abscesses)
- petechiae (25%)
- NUG
Interesting….In less than __% of classic infectious mononucleosis cases, patients experience fatigue persisting for several weeks to months
10%
you’d think this is more common
Interesting, some studies suggest that infectious mononucleosis increases the risk for developing ________ later in life.
multiple sclerosis
5 things for Mono dx:
1.clinical presentation combined
2. greater than 10% atypical lymphocytes on a
peripheral blood smear
3.positive heterophile antibody test using:
3a. Paul-Bunnell test
3b. Monospot: rapid slide agglutination
(Heterophile antibodies are IgM antibodies that are
directed against viral antigens and cross-react with sheep and horse erythrocytes)
Children under 4 years frequently test negative for these
Why should penicillins be avoided in patients w Mono? (beyond the fact that antibiotics dont work on viruses, but hey Mono and Strep throat can look similar)
nonallergic morbilliform skin rashes (hives)
Tonsillar involvement may resemble streptococcal pharyngitis or tonsillitis. However, ampicillin,
amoxicillin, or other penicillins should be avoided because these antibiotics commonly cause nonallergic morbilliform skin rashes in patients with infectious mononucleosis.
What medications have been used sucessfully for the temporary resolution of OHL?
antivirals (acyclovir, valascylovir, famciclovir mentioned)
Which viral infection represents the most common cause of nonhereditary sensorineural hearing loss, with infected infants often developing hearing loss at birth or later in childhood.
CMV (although 90% of infections are asymptomatic)
While CMV and EBV mononucleosis can have similar symptoms, what is one thing that can usually set them apart clinically?
Exudative Pharyngitis seen in EBV, not in CMV
along with LAD and hepatosplenomegaly in EBV and not CMV, but my brain can only fit so much in it
What are the 2 most common manifestations of CMV infection in AIDS patients?
- chorioretinitis (chorioid is the layer between the sclera and the retina, may cause blindness)
- gastrointestinal involvement (bloody diarrhea or odynophagia)
Neonatal CMV infection can have effects on tooth formation like (4)….
- diffuse enamel hypoplasia
- significant attrition
- enamel hypomaturation
- yellow coloration from underlying dentin
(so all enamel problems essentially)
Where do you look for CMV cellular changes? What is the buzzword for the cytologic appearance?
endothelial cells and salivary ductal cells…“owl eye” alterations
What 2 stains can show the cytoplasmic inclusions of a CMV infected cell?
GMS and PAS
Diagnostic tests for CMV (#)
- ELISA
- serum: 4x increase in IgG and IgM antibodies to CMV
- Plasma viral load by PCR (immunocompromised pts)
CMV should resolve spontaneously, but in immunocompromised patients what is the go to?
Ganciclovir
