25 - 165 - VARICELLA AND HERPES ZOSTER

Question 1

What virus causes varicella and herpes zoster?

Answer 1

varicella-zoster virus (VZV)

Question 2

What virus causes herpes zoster

Answer 2

varicella-zoster virus (VZV).

Question 3

Clinical manifestations of varicella

Answer 3

The rash of varicella usually begins on the face and scalp and spreads rapidly to the trunk, with relative sparing of the extremities. Lesions are scattered, rather than clustered, reflecting viremic spread to the skin, and they progress sequentially from rose-colored macules to papules, vesicles, pustules, and crusts. Lesions in all stages are usually present at the same time.

Question 4

Compare the severity of varicella in children and adults

Answer 4

In immunocompetent children, systemic symptoms are usually mild and serious complications are rare.

In adults and immunocompromised persons of any age, varicella is more likely to be severe and can be associated with life-threatening complications.

Question 5

Herpes zoster is most common in what population

Answer 5

Older adults and immunocompromized individuals

Question 6

Most common debilitating complication of herpes zoster

Answer 6

Chronic neuropathic pain (Postherpetic neuralgia)

Question 7

Varicella is common in what age population

Answer 7

Children

Question 8

Infectious period of varicella

Answer 8

1-2 days before appearance of exanthem until 4 - 5 days therafter, until all vesicles have crusted

Question 9

Mean incubation period of varicella infection

Answer 9

14 - 17 days

Question 10

major route by which varicella is acquired and transmitted

Answer 10

respiratory tract by airborne droplets or aerosols, but infection also may be spread by direct contact

Question 11

T/F: Varicella crusts are not infectious

Answer 11

True

Question 12

occurs in individuals who develop varicella early in infancy in the presence of maternal antibody or following postexposure prophylaxis with varicella-zoster immune globulin or varicella vaccine

Answer 12

Modified varicella

Question 13

occurs when vaccinated individuals are reinfected following exposure to wildtype VZV

Answer 13

Breakthrough varicella

Question 14

T/F: Herpes zoster can be acquired through exposure to Varicella and herpes zoster

Answer 14

False

There is no convincing evidence that herpes zoster can be acquired by contact with persons with varicella or herpes zoster. 1 Rather, the incidence of herpes zoster is determined by factors that influence the host–virus relationship and the presence of immune responses necessary to prevent reactivation of latent VZV

Question 15

major risk factor for herpes zoster

Answer 15

• Age
• Decreased VZV-specific cell-mediated immunity (Immunocompromising conditions associated with increased risk of herpes zoster include bone marrow and solid organ transplants, hematologic and solid tumor malignancies, and immune-mediated diseases (eg, systemic lupus erythematous, rheumatoid arthritis)
• Other factors reported to correlate with the risk of herpes zoster include female sex, 32 physical trauma in the affected dermatome, 46 IL-10 gene polymorphisms,47 family history of herpes zoster, 48-50and white race

Question 16

characteristic feature of varicella lesions

Answer 16

A characteristic feature of varicella lesions is their rapid progression, over as little as 12 hours, from rosecolored macules to papules, and then to vesicles, pustules, and crusts

Question 17

Describe the typical vesicle of varicella

Answer 17

The typical vesicle is 2 to 3 mm in diameter and elliptical, with its long axis parallel to the folds of the skin. The early vesicle is superficial and thin-walled, and surrounded by an irregular area of erythema, which gives the lesions the appearance of a “dewdrop on a rose petal.

Question 18

distinctive feature of varicella

Answer 18

simultaneous presence, in any one area of the skin, of lesions in all stages of development

Question 19

Prodrome in varicella is more common what age group

Answer 19

Older children and adults

In young children, prodromal symptoms are uncommon. In older children and adults, the rash is often preceded by 2 to 3 days of mild fever, chills, malaise, headache, anorexia, backache and, in some patients, sore throat and dry cough.

Question 20

Most common complication of varicella in normal children

Answer 20

Secondary bacterial infection of skin lesions, usually by Staphylococci or Streptococci, which may produce impetigo, cellulitis, erysipelas, and, rarely, necrotizing fasciitis

Question 21

Can varicella produce bullous lesions?

Answer 21

Yes.

Bullous lesions may develop when vesicles are superinfected by Staphylococci that produce exfoliative toxins.

Question 22

characterize varicella in adults based on symptoms, rash and complications

Answer 22

In adults, fever and constitutional symptoms are more prominent and prolonged, the rash of varicella is more profuse, and complications are more frequent.

Question 23

major severe complication of varicella in adults

Answer 23

Varicella Pneumonia

Varicella pneumonia is characterized by cough, dyspnea, tachypnea, high fever, pleuritic chest pain, cyanosis, and hemoptysis beginning 1 to 6 days after rash onset.

The severity of the symptoms usually exceeds the physical findings, but imaging typically reveals diffuse, peribronchial nodular densities throughout both lung fields with a tendency to concentrate in the perihilar regions and at the bases. The mortality in adults with frank varicella pneumonia is estimated to be between 10% and 30%, but it is less than 10% if immunocompromised patients are excluded and patients receive prompt antiviral therapy

Question 24

The highest risk (2%) of occurrence of congenital varicella syndrome when maternal varicella occurs between what AOG?

Answer 24

13 - 20 weeks AOG.

Question 25

varicella-associated Reye syndrome (acute encephalopathy with fatty degeneration of the liver) may occur in patients treated with what drug?

Answer 25

Salicylates

Question 26

In herpes zoster, Pain and paresthesia in the involved dermatome often precede the eruption by how many days

Answer 26

1 to 3 days but occasional a week or longer

Question 27

A few patients experience acute segmental neuralgia without ever developing a cutaneous eruption—a condition known as

Answer 27

zoster sine herpete

Question 28

Most frequently affected nerve in herpes zoster

Answer 28

trigeminal nerve, particularly the ophthalmic division (10%-15%), and the trunk from T3 to L2 (>50%),

Question 29

Differentiate herpes zoster and varicella based on virus spread

Answer 29

intraneural (axonal) spread of virus to the skin in herpes zoster, as opposed to viremic spread in varicella.

Question 30

Describe the evolution of lesions of herpes zoster

Answer 30

Herpes zoster lesions begin as erythematous macules and papules in a dermatomal distribution. Vesicles form within 12 to 24 hours and evolve into pustules by the third day (Fig. 165-3E). These dry and crust in 7 to 10 days. The crusts generally persist for 2 to 3 weeks. In normal individuals, new lesions continue to appear for 1 to 4 days (occasionally for as long as 7 days). The rash is most severe and lasts longest in older people, and is least severe and of shortest duration in children.

Question 31

What nerve is associated with hutchinson sign

Answer 31

Nasociliary branch of the ophthalmic division of the trigeminal nerve Involvement of the nasociliary branch, which innervates the eye, as well as the tip and side of the nose, provides VZV with direct access to intraocular structures. Thus, when ophthalmic zoster involves the tip and the side of the nose (Hutchinson sign), careful attention must be given to the condition of the eye. Involvement of the nasociliary branch is frequently accompanied by unilateral conjunctivitis and impaired corneal sensation, which can lead to corneal ulceration and sight-threatening bacterial infection. The eye is involved in 20% to 70% of patients with ophthalmic zoster.

Question 32

Syndrome that results from involvement of facial and auditory nerves

Answer 32

Ramsay Hunt syndrome (facial palsy in combination with herpes zoster of the external ear, ear canal, or tympanic membrane, with or without tinnitus, vertigo, and deafness)

Question 33

Cardinal symptom of herpes zoster

Answer 33

Pain

Question 34

Complications of Herpes Zoster

Answer 34

Question 35

most significant risk factor for PHN

Answer 35

Age

Question 36

Most serious complications of herpes zoster are more common in immunocompromised persons. These include _____

Answer 36

necrosis of skin and scarring, and cutaneous dissemination Patients with cutaneous dissemination may also have widespread, often fatal, visceral dissemination, particularly to the lungs, liver, and brain.

Question 37

Question 38

best diagnostic test for detection of VZV

Answer 38

Polymerase chain reaction (PCR) because of its very high sensitivity and specificity, ready availability, and relatively quick (1 day or less) turnaround time.

Question 39

best specimen for PCR analysis of VZV

Answer 39

Vesicle fluid but lesion scrapings, crusts, tissue biopsy, or cerebrospinal fluid are equally useful

Question 40

Papular lesions of varicella evolve into intraepithelial vesicles within how many hours

Answer 40

12 - 24 hours

Question 41

guanosine analogs that are selectively phosphorylated by VZV thymidine kinase; they are poor substrates for cellular thymidine kinase and thus are not activated in, and are not toxic for, uninfected cells

Answer 41

acyclovir and penciclovir

Question 42

Prodrug of penciclovir

Answer 42

Famciclovir

Question 43

thymidine analog, also activated by viral thymidine kinase, with very high activity against VZV

Answer 43

Brivudin

Question 44

* second-line drug that is an analog of inorganic pyrophosphate, inhibits the replication of all known herpesviruses in vitro * it does not require phosphorylation by thymidine kinase to be activated and is therefore active against nucleoside-resistant VZV mutants

Answer 44

Foscarnet

Question 45

potent helicase-primase inhibitor that is active against acyclovir-resistant VZV and HSV

Answer 45

Amenamevir

Question 46

True or false: Topical antiviral therapy is an option for treatment of varicella

Answer 46

False Topical antiviral therapy has no role in the treatment of varicella. It has limited efficacy against herpes zoster and is not recommended

Question 47

Preferred oral therapy for VZV infections

Answer 47

FAMCICLOVIR OR VALACYCLOVIR Because of their superior pharmacokinetics and the reduced sensitivity of VZV compared to HSV to acyclovir and penciclovir, famciclovir, or valacyclovir are preferred over acyclovir for oral therapy of VZV infections.

Question 48

Topical therapy for varicella

Answer 48

- Cool compresses, - calamine lotion or Caladryl Clear (zinc acetate 0.1% + pramoxine 1%) locally, - tepid baths with baking soda or colloidal oatmeal (3 cups per tub of water), and - oral antihistamines may relieve itching. - Creams and lotions containing glucocorticoids and occlusive ointments should not be used. - Antipyretics may be needed, but salicylates must be avoided because of their association with Reye syndrome.

Question 49

In what instances can you give antiviral medication for varicella?

Answer 49

- Some experts favor its use where cost is not a concern; - when it can be begun in time to benefit the patient (within 24 hours of rash onset); and - where there is a perceived need to speed resolution of the infection.

Question 50

Recommendations for initiation of oral antiviral therapy for varicella

Answer 50

- preferably valacyclovir or famciclovir, for persons >12 years of age - persons with chronic cutaneous or pulmonary disorders or other debilitating diseases, - persons receiving long-term salicylate therapy, and - persons receiving short, intermittent, or aerosolized courses of corticosteroids because these individuals are at increased risk for moderate-to-severe varicella

Question 51

Why is famciclovir or valacyclovir preferred over acyclovir for treatment of herpes zoster?

Answer 51

because of their thrice-daily dosing schedule, their greater oral bioavailability, and the higher and more reliable blood levels of antiviral activity achieved. This is important because of the reduced sensitivity to acyclovir of VZV compared with HSV, and the potential existence of barriers to the entry of antiviral agents into tissues that are sites of VZV replication.

Question 52

In VZV infections, the utility of antiviral agents is unproven if treatment is initiated more than how many hours?

Answer 52

72 hours after rash onset

Question 53

Antiviral Treatment of Varicella in the Normal and Immunocompromised Host

Answer 53

Question 54

VARICELLA Treatment regimen for Adolescent (≥40 kg) or adult, especially with mild immunocompromise (eg, use of inhaled glucocorticoids)

Answer 54

- Valacyclovir 1 g orally every 8 h for 7 d or - Famciclovir 500 mg orally every 8 h for 7 d or - Acyclovir 800 mg orally 5 times a day for 7 days

Question 55

Varicella treatment regimen for neonates

Answer 55

- Acyclovir 10mg/kg or 500 mg/m2 q8 x 10 days

Question 56

Varicella treatment regimen for patients who develop pneumonia

Answer 56

Acyclovir 10 mg/kg IV q8 x 7-10d

Question 57

Varicella Treatment regimen for Acyclovir resistant patients (advanced AIDS)

Answer 57

Foscarnet 40 mg/kg IV q8 until healed

Question 58

Instances where administration of antiviral meds is prudent to initiate even after 72 hours of rash onset

Answer 58

it is prudent to initiate antiviral therapy even if more than 72 hours have elapsed after rash onset in patients with: - herpes zoster involving cranial nerves (eg, ophthalmic zoster), - in patients who continue to have new vesicle formation, or - in patients who are of advanced age and may thus have a delay in development of effective immune responses

Question 59

Question 60

Herpes zoster regimen for patients < 50 y/o

Answer 60

- symptomatic treatment alone or - famciclovir 500 mg orally q8 x 7d or - valacyclovir 1g orally q8 x 7 days or - acyclovir 800 mg orally 5x/day for 7 days

Question 61

Herpes zoster treatment regimen for e ≥50 y, and patients of any age with cranial nerve involvement (eg, ophthalmic zoster)

Answer 61

- famciclovir 500 mg orally q8 x 7d or - valacyclovir 1g orally q8 x 7 days or - acyclovir 800 mg orally 5x/day for 7 days

Question 62

Treatment regimen for patients with severe varicella or severe immunocompromise (varecella or zoster)

Answer 62

Acyclovir 10 mg/kg IV q8 x 7 - 10 days

Question 63

Varicella and herpes zoster treatment regimen for Mild immunocompromise, including HIV-1 infection

Answer 63

- Valacyclovir 1 g orally every 8 h for 7-10 d or - Famciclovir 500 mg orally every 8 h for 7-10 d or - Acyclovir 800 mg orally 5 times a day for 7-10 days

Question 64

What vaccine is effecacious in protecting susceptible children agaist varicella

Answer 64

Live attenuated Oka VZV varicella vaccines 2 doses given 4 to 8 weeks apart

Question 65

In 2005, the FDA approved a combined measles, mumps, rubella, and varicella (MMRV) vaccine for routine immunization of children what age?

Answer 65

12 months to 12 years of age

Question 66

Because of the frequency of breakthrough varicella, the CDC Advisory Committee on Immunization Practices (ACIP) now recommends hoe many doses of varicella vaccine

Answer 66

two 0.5-mL doses of varicella vaccine for healthy children aged ≥12 months, and for all adolescents and adults without evidence of immunity.

Question 67

What is considered significant exposure to varicella and herpes zoster?

Answer 67

risk period of 1-2 days before rash until crusting is well under way

Question 68

When exposure is recognized (risk period of 1-2 days before rash until crusting is well under way), preventive measures include _________

Answer 68

- varicella vaccine, - high-titer varicella-zoster immune globulin (VARIZIG), and - postexposure chemoprophylaxis with acyclovir

Question 69

Active immunization with varicella vaccine is effective in preventing illness or modifying varicella severity in immunocompetent children if administered within how many days of exposure?

Answer 69

Within 3 days after exposure

Question 70

VARIZIG, a purified human immune globulin prepared from plasma containing high levels of immunoglobulin G antibody to VZV, may be considered for patients who have been exposed to varicella and are at increased risk for severe disease and complications. It is dosed on a weight basis and should be given as soon as possible, preferably within how many hours of exposure?

Answer 70

Within 96 hours of exposure, although current recommendations permit an interval of up to 10 days

Question 71

T/F: Protection afforded by VARIZIG is TRANSIENT, varicella vaccine induces LONG-LASTING VZV immunity and protection against subsequent exposures.

Answer 71

TRUE Therefore, the ACIP recommends varicella vaccine for postexposure prophylaxis in unvaccinated susceptible immunocompetent persons

Question 72

Clinically significant PHN is defined as pain and discomfort (eg, allodynia, severe pruritus) due to herpes zoster scored as ______ on a 0-10 scale that persists for more than _____ days after rash onset.

Answer 72

≥3 90

Question 73

In 2006, the ACIP recommended routine administration of _____________ to adults 60 years of age and older for the prevention of herpes zoster and its complications, particularly PHN.

Answer 73

live attenuated Oka/Merck strain VZV zoster vaccine (ZVL; Zostavax® )

Question 74

Question 75

Varicella is infectious ______ days before to ______ days after. a. 2-3 days before to 3-4 days after b. 1-2 days before to 3-4 days after c. 2-3 days before to 4-5 days after d. 1-2 days before to 4-5 days after

Answer 75

C

Question 76

A distinctive feature of varicella is ____________. a. Dewdrop on a rose petal b. Crusting with shallow pink depressions c. Simultaneous presence, in any one area of the skin, of lesions in all stages of development d. Localization and distribution of rash – unilateral, generally limited to the area of skin innervated by a single sensory ganglion

Answer 76

C

Question 77

The following are risk factors for herpes zoster infection except _____ . a. Increasing age b. Physical trauma c. Family history d. Male gender

Answer 77

D

Question 78

A distinctive feature of herpes zoster: a. Dewdrop on a rose petal b. Crusting with shallow pink depressions c. Simultaneous presence, in any one area of the skin, of lesions in all stages of development d. Localization and distribution of rash – unilateral, generally limited to the area of skin innervated by a single sensory ganglion

Answer 78

D

Question 79

Hutchinson sign involves the ______. a. Upper eyelid b. Lower eyelid c. Tip and side of the nose d. Temporal side of face

Answer 79

C

Question 80

_____________ is required for recovery from varicella. a. T-cell mediated immunity b. B-cell mediated immunity c. IL-10 mediated d. NK-cell mediated

Answer 80

A

Question 81

Antiviral treatment of Herpes Zoster for immunocompetent host include the ff. Except _______ . a. Symptomatic treatment b. Famciclovir 500 mg q8 x 7 days c. Valacyclovir 1g q8 x 7 days d. Foscarnet 40mg/kg IV q8 until healed

Answer 81

D

Question 82

what is the % likelihood of recurrent herpes zoster

Answer 82

1 - 6 % ## Footnote * Recurrent herpes zoster is more common in patients who are immunocompromised, and they are more likely to have multidermatomal or bilateral disease * Immunocompetent patients thought to be suffering multiple episodes of herpes zoster, especially when they occur in the same dermatome, are more likely to have recurrent zosteriform