Varicella zoster

Question 1

What is chickenpox

Answer 1

Chickenpox is caused by primary infection with varicella zoster virus.

Question 2

What is shingles

Answer 2

Shingles is a reactivation of the dormant virus in dorsal root ganglion

Question 3

What is the transmission

Answer 3

spread via the respiratory route
can be caught from someone with shingles

Question 4

What is the infectivity and incubation

Answer 4

infectivity = 4 days before rash, until 5 days after the rash first appeared*
incubation period = 10-21 days

Question 5

What are the clinical features

Answer 5

Fever
itchy, rash starting on head/trunk before spreading. Initially macular then papular then vesicular
systemic upset is usually mild

Question 6

What is the management of chicken pox

Answer 6

keep cool, trim nails
calamine lotion

Question 7

When children be excluded

Answer 7

he most infectious period is 1–2 days before the rash appears, but infectivity continues until all the lesions are dry and have crusted over (usually about 5 days after the onset of the rash).

Question 8

what should immunocompromised patients and newborns with peripartum exposure receive

Answer 8

Varicella zoster immunoglobulin

Question 9

What is a secondary complication

Answer 9

bacterial infection of the lesions - INCREASED RISK WITH nsaids

Question 10

What can occur as a result of bacterial infection

Answer 10

whilst this commonly may manifest as a single infected lesion/small area of cellulitis, in a small number of patients invasive group A streptococcal soft tissue infections may occur resulting in necrotizing fasciitis

Question 11

What are the rare complication

Answer 11

pneumonia
encephalitis (cerebellar involvement may be seen)
disseminated haemorrhagic chickenpox
arthritis, nephritis and pancreatitis may very rarely be seen

Question 12

What is shingles

Answer 12

acute, unilateral, painful blistering rash caused by reactivation of the varicella-zoster virus (VZV), the virus lies dormant in the dorsal root or cranial nerve ganglia.

Question 13

What are the risk factors for shingles

Answer 13

increasing age
HIV: strong risk factor, 15 times more common
other immunosuppressive conditions (e.g. steroids, chemotherapy)

Question 14

What are the most affected dermatomes

Answer 14

T1-L2

Question 15

What occurs during the prodromal period

Answer 15

burning pain over the affected dermatome for 2-3 days
pain may be severe and interfere with sleep
around 20% of patients will experience fever, headache, lethargy

Question 16

What is the rash like in shingles

Answer 16

initially erythematous, macular rash over the affected dermatome
quickly becomes vesicular
characteristically is well demarcated by the dermatome and does not cross the midline. However, some ‘bleeding’ into adjacent areas may be seen

Question 17

What is advised to shingles patients

Answer 17

remind patients they are potentially infectious
may need to avoid pregnant women and the immunosuppressed
should be advised that they are infectious until the vesicles have crusted over, usually 5-7 days following onset
covering lesions reduces the risk

Question 18

What analgesia should be given in shingles

Answer 18

paracetamol and NSAIDs are first-line
if not responding then use of neuropathic agents (e.g. amitriptyline) can be considered
oral corticosteroids may be considered in the first 2 weeks in immunocompetent adults with localized shingles if the pain is severe and not responding to the above treatments

Question 19

When to give anti virals in shingles

Answer 19

in practice, they recommend antivirals within 72 hours for the majority of patients, unless the patient is < 50 years and has a ‘mild’ truncal rash associated with mild pain and no underlying risk factors

Question 20

What are the benefits of giving anti virals

Answer 20

reduced incidence of post-herpetic neuralgia, particularly in older people

Question 21

What are the antivirals used in shingles

Answer 21

aciclovir, famciclovir, or valaciclovir are recommended

Question 22

What is the most common complication

Answer 22

Post hepatic neuralgia

Question 23

What is herpes zoster opthalmicus

Answer 23

shingles affecting affecting the ocular division of the trigeminal nerve) is associated with a variety of ocular complications

Question 24

What is heroes zoster optics

Answer 24

Ramsay Hunt syndrome): may result in ear lesions and facial paralysis

Question 25

What can happen to pregnant women with chicken pox

Answer 25

Risks to the mother
5 times greater risk of pneumonitis

Fetal varicella syndrome (FVS)

Question 26

When can FVS occur

Answer 26

risk of FVS following maternal varicella exposure is around 1% if occurs before 20 weeks gestation
studies have shown a very small number of cases occurring between 20-28 weeks gestation and none following 28 weeks

Question 27

What are the features of FVS

Answer 27

include skin scarring, eye defects (microphthalmia), limb hypoplasia, microcephaly and learning disabilities

Question 28

What can happen if there is chicken pox exposure during the second or third trimester

Answer 28

Shingles in infancy

Question 29

What is neonatal Varicella

Answer 29

if the mother develops rash between 5 days before and 2 days after birth there is a risk of neonatal varicella, which may be fatal to the newborn child in around 20% of cases

Question 30

How to determine if there is previous exposure to chicken pox

Answer 30

Maternal blood checked for antibopdies

Question 31

What is given to mothers who are <20 weeks gestation that do not have antibodies

Answer 31

Given VZIG- IS EFFECTIVE UPTO 10 DAYS POST EXPOSURE

Question 32

What to do in mothers who are> 20 weeks who are not immune

Answer 32

Give VZIG or aciclovir 7-14 days after exposure

Question 33

How to manage chickenpox in pregnant women

Answer 33

specialist advice should be sought, oral aciclovir should be given if the pregnant women is ≥ 20 weeks and she presents within 24 hours of onset of the rash
if the woman is < 20 weeks the aciclovir should be ‘considered with caution’

Question 34

Who is given VZIG

Answer 34

1. significant exposure to chickenpox or herpes zoster
   e.g. exposure to limited, covered-up shingles may not warrant post-exposure prophylaxis
2. a clinical condition that increases the risk of severe varicella; this includes immunosuppressed patients, neonates and pregnant women
   e.g. long-term steroids, methotrexate and other common immunosuppressants
3. no antibodies to the varicella virus
   ideally all at-risk exposed patients should have a blood test for varicella antibodies
   this should not, however, delay post-exposure prophylaxis past 7 days after initial contact

Question 35

What are the two types of varicella zoster vaccine

Answer 35

a vaccine that stops you from developing primary varicella infection (chickenpox)
a vaccine that reduces the incidence of herpes zoster (shingles) caused by reactivation of VZV

Question 36

Who is given the live attenuated vaccine

Answer 36

healthcare workers who are not already immune to VZV
contacts of immunocompromised patients (e.g. child whose parent is undergoing chemotherapy)

Question 37

Examples of live attenuated vaccine

Answer 37

Varilrix and Varivax.

Question 38

Who is given the shingles vaccine and how

Answer 38

offered to all patients aged 70-79 years*
is live-attenuated and given sub-cutaneously
examples include Zostavax

Question 39

What are the contraindications of live vaccine

Answer 39

Immunosuppressed individuals