skin 5: chicken pox

Question 1

Chickenpox (varicella) is ??
affects what age group??
how severe??

Answer 1

a highly contagious, generalized vesicular exanthematous disease of seasonally epidemic propensity caused by varicella-zoster virus (VZV)

mild, self-limiting childhood disease, but it does cause significant morbidity and mortality in some children (i.e., immune compromised) and especially in adults

Question 2

Shingles (zoster) is a ??

Answer 2

disease caused by a recrudescence of the same virus as chicken pox.
VZV, like all herpesviruses, is a latent virus.

Question 3

VZV etiology

Answer 3

an alpha herpesvirus (enveloped, dsDNA virus which encodes its own thymidine kinase) with one serotype.
VZV is closely related to HSV-1 and HSV-2

Question 4

Herpesviridae

Answer 4

large, enveloped dsDNA viruses.

• possess a unique gene that encodes for thymidine kinase that activates herpes antiviral agents and allows for targeting by the drugs.
• 8 different herpesviruses are known to infect humans, the sole host and reservoir.
• numerous other herpesviruses infect other primates, cows (bovine), etc. that may be occasional or accidental pathogens for humans.

Question 5

8 different HHVs

Answer 5

Human Herpesvirus-1 = HHV-1, Herpes simplex virus (HSV)-1; α group)
Human Herpesvirus-2 = HHV-2, Herpes simplex virus (HSV-2; (α group)
Human Herpesvirus-3 = HHV-3, Varicella-Zoster Virus (VZV; (α group)
Human Herpesvirus-4 = HHV-4, Epstein-Barr Virus (EBV; γ group)
Human Herpesvirus-5 = HHV-5, Cytomegalovirus (CMV; β group)
Human Herpesvirus-6 = HHV-6 (β group)
Human Herpesvirus-7 = HHV-7 (β group)
Human Herpesvirus-8 = HHV-8 (Kaposi sarcoma associated herpesvirus; γ group)

Question 6

Varicella hosts?
age?
season?
POE?

Answer 6

Humans are the only host. Carrier state

1 -6 years-of-age. Approx. 5% of adults are susceptible
winter and early spring

POE is the URT or conjunctiva, spread via direct contact with respiratory secretions (primary) and secondary POE is skin lesions

Question 7

Varicella, contagious?

when no longer contagious?

reinfection?

Answer 7

highly contagious –Primary attack rate >90% and secondary attack rate is 80%.
most contagious 1 to 2 days before rash appears to 4 to 5 days after.
Once scabs have formed on all lesions and there are no new lesions, the patient is no longer infectious

Re-infection is rare and the course tends to be milder.

Question 8

Zoster (aka belt, girdle, shingles) common??
can be a source of ??
season?

Answer 8

Common. 500,000-750,000 cases per year in the U.S and the incidence is rising as immunosuppressed population increases.

The zoster (shingles) patient can be the source of chickenpox outbreaks in a community.

no seasonality because this is a reactivated infection.

Question 9

Zoster: predisposing factors, occurs in who?

Answer 9

Adults, with the highest rate among those over 60 years-of-age.
Immunocompromised children
Cancer pt.
For 30% of zoster pt., there is no known predisposing factor.

Question 10

VZV: incubation period??

Answer 10

14 to 16 days; range is 10 to 21 days

Question 11

Initial VZV multiplication occurs in the ??, then the ??;

then resulting in a ?? 4-6 days following infection

Answer 11

mucosa of the URT
draining lymph nodes
viremia

Question 12

During the primary viremia, the VZV infects and replicates in ??

Answer 12

lymphoid tissue in the liver, spleen and possibly other organs.

Question 13

Secondary viremia occurs about 10 to 14 days post-infection and is coincident with the appearance of ??

?? are found in lesions.

There are 5 to 6 temperature spikes and each coinciding with the appearance of ??

Answer 13

fever and a vesicular rash.

Both virus and antibody complexes

a new set of lesions.

Question 14

The virus becomes latent in ?? after primary infection.

Rarely, the virus will travel up arteries to the brain causing an ??

Answer 14

dorsal root or cranial nerves (trigeminal ganglia)

ischemic stroke: 1 child/15,000 with chickenpox.

Question 15

Clinical Manifestations: Varicella: prodrome??

Answer 15

Prodromal symptoms are usually absent in the young.

In older children and adults there is a prodrome of flu-like symptoms 24-48 hours prior to rash

Question 16

Varicella: symptoms during primary disease

Answer 16

mild to high fever; malaise, anorexia, headache, vomiting and rash.

Question 17

Varicella: rash appears first??

what type of pattern??

Answer 17

first on the on head (scalp sometimes, face) or trunk and becomes generalized,
but is more severe on head and trunk than on the extremities (centripetal pattern)

Question 18

Varicella rash characteristics: starts out as ?? then within hours become ??

Within 24-48 h, vesicles become ??

New vesicular lesions occur over the next ?? days
corresponding with ??

Answer 18

starts out as a pruritic, red, maculopapular rash then within hours, each lesion is a small, thin-walled vesicle on a maculopapular base (dew drop on a rose petal).

pustular, crusted, then scabbed.

3-6 days, corresponding with each fever spike, so that at any given time, all stages of the skin lesions are visible for some time

Question 19

Varicella: more lesions

Answer 19

Painful, ulcerative lesions occur on mucous membranes of oropharynx, conjunctiva, vagina.

patient is infectious until all lesions have scabbed and no new lesions are visible.

Question 20

Varicella Lesions can scar if they become ?? by what ??

the most common reason for hospitalization of children with varicella ??

Answer 20

secondarily bacterial infected - impetiginized by group A Strep (GAS, Streptococcus pyogenes) or by Staphylococcus aureus and form a honey-colored crust over the lesion.

is this complication It is rare for scarring to occur in non-impetiginized lesions.

Question 21

Varicella Re-infection: Occurs in about ??

factors??

Answer 21

5% of all cases usually in persons whose first infection was a mild case as a young child.

Genetics is a factor. Some have asymptomatic or mild infections and will seroconvert. Later in life, they may report having not had chickenpox but will be seropositive and may develop zoster.

Question 22

Varicella Adult infection: more or less severe than in children??
typically have 1+ of the following:

Answer 22

MORE
Interstitial pneumonia (20 to 30% of adults)
Hepatitis
Meningoencephalitis
Thrombocytopenia
Other complications

Question 23

Varicella maternal disease: when is neonate at high risk for severe VZV infection??

Answer 23

4 to 5 days pre-partum to 2 to 3 days post-partum

Question 24

Maternal Varicella manifestation

Answer 24

During primary infection or with recrudescence (herpes zoster), a disseminated infection involving all tissues and organs can occur that can be fatal. The lesions are hemorrhagic, i.e. non-blanching

Question 25

Herpes zoster is a recrudescence or reactivation of latent VZV infection due to
??
when this occurs, the virus follows the nerve pathway to a dermatome following ?? from ??

Answer 25

waning cell-mediated immunity (CMI) to VZV later in life or during immunosuppression.

reverse axoplasmic flow from the dorsal root ganglion (DRG)

Question 26

Herpes zoster risk factors

The suppressed CMI allows ??

how is the virus limited in its spread ??

Answer 26

Age, disease, drug-induced reduction CMI, environmental stress, etc

reactivation/proliferation of VZV causing neuronal destruction, inflammation and pain at the site.

The virus is probably limited in its spread and does not disseminate because antibody prevents it.

Question 27

The zoster pt.: infectious??

Answer 27

The zoster pt. is infectious. The disease contracted from a zoster patient is varicella, not zoster.

Question 28

zoster initial clinical presentation

Answer 28

Initially tingling sensation or pin-prick sensations followed later by severe pain in areas innervated by the nerve (usually precedes by hours or days)

Question 29

zoster: rash follows tingling: characteristics??

additional symptoms?

Answer 29

The rash is an asymmetrical maculopapular or vesicular-crusting rash following a single thoracic dermatome or cranial nerve distribution.

1. Flu-like symptoms may be present.
2. Pain: acute herpetic neuralgia that lasts for approx.. 30 days after onset of the rash

Question 30

Zoster complications

Answer 30

Ophthalmic or ocular zoster and herpes zoster oticus (involving the geniculate
ganglion, i.e., the ear) must be referred to appropriate specialist as a medical
emergency

More severe, widespread rashes occur in immunosuppressed individuals.

Question 31

Zoster complications: Postherpetic neuralgia -
may last how long?
more common in who?

Answer 31

a severe burning, lancinating pain, can be debilitating, typically accompanied by allodynia (pain from non-noxious stimuli).
It may persist for >120 days (4mos!) after the rash has healed and occurs in 10% of all cases but at a much higher incidence in those ≥60 y-o-age.

Question 32

more Zoster complications related to postherpetic neuralgia:
Acute peripheral facial palsy and idiopathic peripheral facial palsy -

Answer 32

Reactivation of either VZV (Zoster or Zoster Sine Herpete [No rash]) or HSV, Lyme disease, etc.

Unilateral facial paralysis resulting from demyelination by VZV or HSV of the trigeminal nerve, geniculate ganglion of the 7th cranial nerve, the 2nd or 3rd cervical roots or the 5th cranial nerve.

Question 33

Zoster complication: Ramsey-Hunt syndrome:

also, VZV may also soon be added to the growing list of triggers for ??

Answer 33

Acute facial palsy and/or ipsilateral facial palsy plus herpes zoster oticus (board question?).

Guillian-Barre’ syndrome.

Question 34

Other syndromes involving VZV: Congenital varicella syndrome

when is fetus at risk? mother?
only risk to mothers with??

prevention??

Answer 34

VZV can cross the placenta and infect the child in utero

-2% risk of severe VZV infection if fetus is infected during first 20 weeks
-Pregnant mother is at great risk, especially if she is infected in the last
trimester.
-Only risk is to seronegative mothers with no history of
chickenpox.

Can be prevented if varicella-zoster immune globulin (VZIG) is provided
within 72 to 96 hours of exposure

Question 35

VZV dx

Answer 35

Clinical criteria are usually sufficient

Question 36

VZV Laboratory diagnosis.

Answer 36

Presence of multinucleated giant cells with intranuclear inclusions (syncytia formation with Cowdry type A intranuclear inclusions) are present in skin lesions, respiratory specimens or organ biopsies.
DFA or Tzanck smear of scraping from the base of the lesion can also be diagnostic.
Virus can be isolated from the lesions using mammalian cell culture – not routine.

Question 37

VZV dx: serologic testing used to ??
Especially important in ??

who should be vaccinated??

Answer 37

establish immune status in adults.
-pregnant women who have been exposed and prior to clinician training and rotations for health professional students.

If there is no history of chickenpox, and no history of infection as indicated by the presence of antibodies, you should get vaccinated.

Question 38

tx for immunocompetent children with varicella:

Answer 38

symtomatic:
-lotion or antihistamines for pruritus.
-ASA is contraindicated (Reye’s syndrome- also
associated with influenza virus and essentially any febrile illness of childhood) -Acetaminophen or other antipyretics are recommended during childhood.

Question 39

VZIG is?

Answer 39

• pooled  globulin from selected population of donors with higher anti-VZV titer

Question 40

VZIG is recommended for persons who fulfill all 3 requirements :

Answer 40

-VZV susceptible (as determined by seronegativity)
-Exposure to VZV is likely to result in VZV infection
-At increased risk for complication compared to general population, i.e.,
adolescents, adults or immunosuppressed children with specific leukemia,
pregnant women

Question 41

VZIG: must be administered within ??

can VZIG be used as tx?

Answer 41

72-96 h (3-4 days) post-
exposure to obtain full or partial protection.
-NOT a treatment for any type of VZV infection or disease.

Question 42

Varicella Antiviral and palliative therapy:
effective when administered ??
Only recommend for ??
why??

Answer 42

Oral acyclovir administered 9 days or fewer post-infection can prevent/minimize
signs and symptoms of disease.
If administered within 24 h of onset of varicella symptoms is also efficacious.

-Only recommend for persons at high risk for severe disease, because widespread usage increases risk of thymidine kinase mutation and thus resistance.

Question 43

Zoster Antiviral and palliative therapy:

Must administer within ??

Answer 43

Acyclovir, Famciclovir, Valacyclovir are licensed for modification/treatment of zoster.
-72 h (3 days) of onset of rash to reduce degree and duration of pain.

Question 44

Postherpetic neuralgia tx:

Answer 44

Nortriptyline (a tricyclic antidepressant)
Lidocain patch, 5%
Gabapentin (anticonvulsant - analgesic)
Opioid analgesics (e.g., sustained release oxycodone)
Nucleoside analog (acyclovir, famciclovir, valacyclovir, brivudin)

Question 45

VZV prevention, vaccine??
given to who and with what else??

more or less effective than WT chicken pox ?

Answer 45

Live attenuated vaccine (Varivax®)
Children 13 months to 12 years-of-age and in susceptible adolescent and adult populations and administered on same schedule as MMR vaccine. Significantly reduced risk compared to a child who develops wild type chicken pox

Question 46

Varivax efficacy

Answer 46

Efficacy is high with 1 dose in children, 2 doses in adolescents, adults.

90% effective against moderate-to-severe varicella and 56% effective in preventing mild varicella

Question 47

Some recent evidence suggests that children immunized before ?? can acquire chickenpox if exposed at a later date, though the infection course, signs and symptoms are less than if not immunized

Answer 47

18 months, and especially those  14 months of age

Question 48

Varivax, anergy?

Transmission of vaccine strain??
Breakthrough?? when?

Answer 48

Some anergy. However, in all cases, symptoms are extremely mild, no significant VZV sequelae occur, immunity to both vaccine and wild-type strain is boosted.

Transmission of vaccine strain to susceptible persons is extremely rare.

Breakthrough chickenpox is most likely >5 years post-vaccination unless
immunized at  14 months in which case, it can occur sooner

Question 49

Other recommendations for VZV vaccination

Answer 49

• 3 -5 days post-exposure to prevent/ameliorate disease potential for immunocompetent persons.
• Persons with humoral immunodeficiencies.
• Has been efficacious in preventing zoster



Question 50

contraindications for VZV vaccination

Answer 50

Pregnant women, women planning to become pregnant in next 3 months.
Immunocompromised children.

Question 51

another VZV vaccine
more/less potent than Varivax?
recommended for who??

The most thorough studies have indicated that the zoster vaccine significantly
reduces the:

Answer 51

Live attenuated vaccine - Zostavax®
Same as Varivax but the potency is 14 times that of the Varivax.
Recommended in adults ≥ 60 years of age.

a. burden of herpes zoster disease by 61%
b. incidence of herpes zoster by 51%
c. incidence of clinically significant post-herpetic neuralgia by 67%
It neither causes nor induces herpes zoster.